> Quick answer: A modern Maximum Power Point Tracking (MPPT) charge controller ensures safe and efficient charging of a LiFePO₄ battery in sub-zero conditions. It dynamically adjusts voltage to maintain peak power, compensates for cold temperatures, prevents overcharging, and manages energy use effectively [2][9][10][13][15][22][23].
During the harsh Romanian winters with their overcast skies and sub-zero temperatures, solar lamps rely on advanced technology to maintain performance. A polycrystalline solar panel generates significantly less power under these conditions, yet a LiFePO₄ battery still requires careful charging to prevent damage and ensure efficient energy transfer. The charge controller plays an essential role in this process by dynamically regulating the voltage and current output from the solar panel.
How MPPT Charge Controllers Work
The primary mechanism enabling efficient charging is Maximum Power Point Tracking (MPPT). This technology dynamically adjusts the electrical load on the solar panel to maintain operation at its peak power point [2][13][18]. Unlike older Pulse Width Modulation (PWM) controllers, which are inefficient in variable or low-light conditions [5][6], MPPT can convert excess voltage from the panel into usable charge [2][13].
For example, a 30–33V solar panel can efficiently charge a 12V battery system through MPPT, capturing energy that would otherwise be lost [2][13]. This is especially critical during overcast days when the panel’s voltage may not match the battery’s charging voltage. The controller adjusts the impedance to extract usable power.
Battery State and Charging Profile
The charge controller continuously monitors the LiFePO₄ battery voltage to determine its state of charge, adjusting the charging profile accordingly [2][13][16]. When the battery is nearly full, the controller tapers the charging current to maintain a constant voltage, preventing overcharging [1][3][4].
Cold temperatures increase the battery’s internal resistance and reduce its ability to accept charge. The controller compensates for this by increasing the charging voltage in cold conditions to ensure proper charging [22][23]. This temperature compensation is essential during sub-zero Romanian winters.
Preventing Battery Damage
A critical feature of a charge controller is Low Voltage Disconnect (LVD), which disconnects the load when battery voltage drops below a set threshold, such as 11.0V [2][13][22]. This prevents deep discharge and preserves enough charge to restart the system when sunlight returns.
In one test, a system maintained battery voltage above 11V for over two months of winter with little sunshine, demonstrating the effectiveness of LVD and energy management [14][19].
Managing Low Solar Input
When available solar power is insufficient to meet the battery’s charging requirements, the controller reduces the charge current to maintain the panel’s voltage at its maximum power point (VMP), maximizing the panel’s output [11][12]. This input voltage regulation ensures that even minimal solar input can sustain operation.
Advanced Charging Profiles
The controller supports advanced charging profiles such as multi-step charging with auto-equalization, though this is more commonly associated with lead-acid batteries. The principle of periodic over-voltage charging (e.g., to 14.5V) to reduce sulfation is mentioned [2][13][17]. However, the sources do not confirm whether such steps are applied to LiFePO₄ batteries.
Temperature-Based Charge Termination
While the specific method for using temperature data to terminate charging in terrestrial systems isn’t confirmed, this suggests that temperature-based logic can be a viable method for charge termination [9][24]. This could be adapted for cold-weather operation, ensuring battery health and performance.
Key Takeaways
- MPPT Technology: Ensures efficient energy transfer by dynamically adjusting the electrical load on the solar panel.
- Temperature Compensation: Increases charging voltage in cold conditions to prevent overcharging and ensure proper charging.
- Low Voltage Disconnect (LVD): Protects against deep discharge, preserving battery life during extended periods of low sunlight.
Frequently Asked Questions
[
{
„q”: „What is the main advantage of using an MPPT charge controller?”,
„a”: „The primary benefit of an MPPT charge controller is its ability to convert excess voltage from the solar panel into usable charge, optimizing energy transfer even in low-light conditions [2][13].”
},
{
„q”: „How does temperature compensation work in a charge controller?”,
„a”: „Temperature compensation adjusts charging voltage based on ambient temperature, increasing it in cold conditions to ensure proper battery charging and prevent overcharging [22][23].”
},
{
„q”: „What is the role of Low Voltage Disconnect (LVD) in solar systems?”,
„a”: „Low Voltage Disconnect (LVD) disconnects the load when battery voltage drops below a set threshold, such as 11.0V, to prevent deep discharge and preserve enough charge for system restart [2][13][22].”
}
]
References
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# Solar Basics (At Home!): What are solar charge controllers? Source: YouTube — Solar Power World URL: https://www.youtube.com/watch?v=iOqJvWRyxSA Video ID: iOqJvWRyxSA Transcript: generated welcome to solar basics i'm kelsey misbrenner senior editor of solar power world and i'm kelly pickerel editor-in-chief customers who want a hybrid solar plus storage system that can sell solar generated electricity during the day and store that power for use at night during an outage or during peak times we'll need a solar charge controller charge controllers are the regulators of solar plus storage systems they deliver power from the pv array to system loads and the battery bank when the battery bank is nearly full the controller will taper off the charging current to maintain the required voltage to fully charge the battery and keep it topped off by being able to regulate the voltage the solar controller protects the battery batteries can be the most expensive part of the system and a solar charge controller protects them from both overcharging and under charging extended periods with a partial state of charge will cause the plates of a lead acid battery to become sulfated and greatly reduce life expectancy lithium battery chemistries are equally vulnerable to chronic undercharging running batteries down to zero can kill them quickly overcharging all types of batteries can cause irreparable damage overcharging lead acid batteries may cause excessive gassing that can actually boil the w
- [2] WO2010057138A2_-_Energy-efficient_solar-powered_outdoor_lighting__593d23e6 — patent
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and which are incorporated by reference into this document. – the battery charge controller is connected between the solar collector and the battery subsystem. – the charge controller controls the current and voltage delivered to the batteries and optimizes the charging conditions to the battery to assure that the batteries are not overcharged, preferably according to the multi-step process portrayed in Figure 40. – the multi-step process features an auto-equalize step (to 14.5V) every 28 days or if low charge, that is preferably 3 hours of over-voltage charge to reduce plate sulfation. – the charge controller provides for low voltage disconnect (LVD) at 11.0V (and reconnect when 12 V is again reached), to prevent damage to the batteries from over-draining. Battery charge is monitored through voltage level, as shown in Figure 41. – the Inventors and Applicant use an advanced Maximum Power Point Tracking technology that converts the voltage from the solar panel that is above the battery voltage into usable energy that can be stored in the batteries. Older technologies, including PWM (pulse width modulation) charge controllers, are unable to do this. Because the batteries are a 12V system and the solar panel is a 30-33V system, significant energy can be converted from the solar panel for storage in the batteries. This enables the system to generate energy on sunny days (or even mostly-sunny days) typically well in excess of what is consumed at night. This excess is stored in th
- [3] How_to_select_a_solar_charge_controller_for_your_PV_system__97277523 — magazine
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# How to select a solar charge controller for your PV system Source: Blog/Web URL: https://www.solarpowerworldonline.com/2019/12/how-to-select-a-solar-charge-controller/ Author: SPW Date: 2019-12-10 By Douglas Grubbs, applications engineer, Morningstar Corporation In its basic forms, solar PV is a very straightforward proposition. Hook a solar panel up to a DC load and it will run until the sun goes down. Connect solar panels to a grid-tied inverter and, as long as the sun is shining, power will be sent to the utility. It’s all fairly easy — until the sun stops shining. Where it starts to get more complex is with energy storage, for use when the sun isn’t shining or when the grid is down. Storing electricity to do useful work later requires batteries connected to a solar PV system. Once a battery is added, a charge controller becomes one of the most important system components. Anyone going off-grid or wanting to use a hybrid system that can sell solar-generated electricity during the day and store that power for use at night, during an outage or during peak times will need a solar charge controller. What a solar charge controller does Think of a solar charge controller as a regulator. It delivers power from the PV array to system loads and the battery bank. When the battery bank is nearly full, the controller will taper off the charging current to maintain the required voltage to fully charge the battery and keep it topped off. By being able to regulate the voltage, the sola
- [4] How_to_select_a_solar_charge_controller_for_your_PV_system__97277523 — authority
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# How to select a solar charge controller for your PV system Source: Blog/Web URL: https://www.solarpowerworldonline.com/2019/12/how-to-select-a-solar-charge-controller/ Author: SPW Date: 2019-12-10 By Douglas Grubbs, applications engineer, Morningstar Corporation In its basic forms, solar PV is a very straightforward proposition. Hook a solar panel up to a DC load and it will run until the sun goes down. Connect solar panels to a grid-tied inverter and, as long as the sun is shining, power will be sent to the utility. It’s all fairly easy — until the sun stops shining. Where it starts to get more complex is with energy storage, for use when the sun isn’t shining or when the grid is down. Storing electricity to do useful work later requires batteries connected to a solar PV system. Once a battery is added, a charge controller becomes one of the most important system components. Anyone going off-grid or wanting to use a hybrid system that can sell solar-generated electricity during the day and store that power for use at night, during an outage or during peak times will need a solar charge controller. What a solar charge controller does Think of a solar charge controller as a regulator. It delivers power from the PV array to system loads and the battery bank. When the battery bank is nearly full, the controller will taper off the charging current to maintain the required voltage to fully charge the battery and keep it topped off. By being able to regulate the voltage, the sola
- [5] What_is_a_solar_charge_controller__556e52bf — magazine
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# What is a solar charge controller? Source: Blog/Web URL: https://www.solarpowerworldonline.com/2015/07/what-is-a-charge-controllers-function/ Author: Joshua Smalley; Intern; SPW Date: 2015-07-20 Any system with energy storage needs a way to regulate the flow of energy into the batteries. Philip Undercuffler, director of strategic platforms at OutBack Power, said that regulation prevents the batteries from overcharging and potentially receiving damage. “Solar charge controllers regulate the energy flowing from the PV array and transfer it directly to the batteries as a DC-coupled system, which is the most efficient and effective manner,” he said. Giving batteries as long of a life as possible is an important function of a charge controller. Two different types of charge controllers exist for solar systems. The first, which Undercuffler simply referred to as the “standard,” is usually small and commonly features pulse-width modulation (PWM). “The PWM controllers are old school and not very efficient,” said Bob Gudgel and Kim Silva of MidNite Solar. PWM technology sends out short controlling pulses to the batteries and is not particularly agile. It lacks the ability to optimize an entire array based on differences between panels, for example. PWM is adequate in places with constant, steady and strong solar radiation and in systems that are cost-sensitive, according to Undercuffler. The second and most common type of controller has maximum power point tracking (MPPT) technology
- [6] What_is_a_solar_charge_controller__556e52bf — authority
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# What is a solar charge controller? Source: Blog/Web URL: https://www.solarpowerworldonline.com/2015/07/what-is-a-charge-controllers-function/ Author: Joshua Smalley; Intern; SPW Date: 2015-07-20 Any system with energy storage needs a way to regulate the flow of energy into the batteries. Philip Undercuffler, director of strategic platforms at OutBack Power, said that regulation prevents the batteries from overcharging and potentially receiving damage. “Solar charge controllers regulate the energy flowing from the PV array and transfer it directly to the batteries as a DC-coupled system, which is the most efficient and effective manner,” he said. Giving batteries as long of a life as possible is an important function of a charge controller. Two different types of charge controllers exist for solar systems. The first, which Undercuffler simply referred to as the “standard,” is usually small and commonly features pulse-width modulation (PWM). “The PWM controllers are old school and not very efficient,” said Bob Gudgel and Kim Silva of MidNite Solar. PWM technology sends out short controlling pulses to the batteries and is not particularly agile. It lacks the ability to optimize an entire array based on differences between panels, for example. PWM is adequate in places with constant, steady and strong solar radiation and in systems that are cost-sensitive, according to Undercuffler. The second and most common type of controller has maximum power point tracking (MPPT) technology
- [9] US5703468A_-_Electrical_charge_control_apparatus_-_Google_Patents__9e2c41a8 — patent
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is broken at preselected intervals to permit the voltage levels of the panel and battery to be tested. The ratio of the voltages is used to determine if a direct connection should be reestablished, or trickle charging through the float regulator should occur. U.S. Pat. No. 4,401,935 discloses an apparatus and method for controlling the charging of a rechargeable battery by a photovoltaic panel and discharging the battery through a lead, in which a relay is switched between a first condition coupling of the battery to the lead and a float regulator, and a second condition coupling of the battery directly to the panel. Exemplary photovoltaic charging systems which employ temperature compensated charging regulation may be found in U.S. Pat. No. 4,349,775 and U.S. Pat. No. 4,622,509. In U.S. Pat. No. 4,349,775, there is provided means for automatic adjustment of the regulator's reference potential in response to monitored temperature changes, thereby providing temperature compensation of the maximum charging voltage and improved protection of the system battery. U.S. Pat. No. 4,622,509 discloses a method and circuit for Ni-Cd battery charge control in low earth orbit spacecraft applications, according to which battery charging is terminated when the battery temperature starts to increase following a decrease at the end of charge. Canadian Patent 1,162,607 and European Patent 342,578 provide disclosures which are based on extensions of the shunt control method of photovoltaic batt
- [10] US20250253703A1_-_Method_for_directly_charging_battery__c5959e18 — patent
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it is discovered that in the latest unit time interval there are severe or violent weather changes, it is determined that the battery is not adapted to be charged. – the latest weather change conditions such as the ambient temperature, the illuminance and the like – the maximum power point voltage is generally low on cloudy days, the maximum power point voltage cannot match the desired battery charging voltage even though the number of series-connected photovoltaic panels is adjusted to a maximum value, whereupon the secondary battery is not adapted to be directly charged, and the reminding information is triggered to be generated and displayed. – step S 2 judging whether the target number of series-connected photovoltaic panels is equal to the current number of series-connected photovoltaic panels, if YES, executing step S 4 , otherwise, executing step S 3 . – step S 2 for example, if the target number of series-connected photovoltaic panels is 6 and the current number of series-connected photovoltaic panels is also 6 , it is not necessary to adjust the number of series-connected photovoltaic panels of each of the photovoltaic panel series branches, and the process may jump to step S 3 , otherwise performing step S 3 to adjust the number of series-connected photovoltaic panels of each of the photovoltaic panel series branches. – step S 3 generating a first control signal according to the target number of series-connected photovoltaic panels, and transmitting the first contro
- [11] How_to_use_solar_power_to_charge_batteries_efficiently__d6070934 — magazine
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# How to use solar power to charge batteries efficiently | Electronics Weekly Source: Blog/Web URL: https://www.electronicsweekly.com/market-sectors/power/use-solar-power-charge-batteries-efficiently-2014-03/ Author: Richard Wilson Date: 2014-03-10 An important characteristic of any solar panel is that it achieves peak power output at a relatively constant operating voltage (VMP) regardless of illumination level. The LT3652 2A battery charger is designed to exploit this characteristic to maintain a solar panel at peak operating efficiency by implementing input voltage regulation (patent pending). When available solar power is inadequate to meet the power requirements of the battery charger, input voltage regulation reduces the battery charge current. This reduces the load on the solar panel to maintain the panel voltage at VMP, maximising the panel output power. This method of achieving peak panel efficiency is called maximum power point control (MPPC). While MPPC optimises solar panel efficiency during periods of low illumination, the power conversion efficiency of the battery charger suffers when power levels are low, degrading the overall power transfer efficiency from the panel to the battery. This article shows how to improve battery charger efficiency by applying a simple PWM charging technique that forces the battery charger to release energy in bursts when power levels are low. Using the Current Monitor Status Pin to Indicate Low Power Conditions The /CHRG current mon
- [12] How_to_use_solar_power_to_charge_batteries_efficiently__d6070934 — authority
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# How to use solar power to charge batteries efficiently | Electronics Weekly Source: Blog/Web URL: https://www.electronicsweekly.com/market-sectors/power/use-solar-power-charge-batteries-efficiently-2014-03/ Author: Richard Wilson Date: 2014-03-10 An important characteristic of any solar panel is that it achieves peak power output at a relatively constant operating voltage (VMP) regardless of illumination level. The LT3652 2A battery charger is designed to exploit this characteristic to maintain a solar panel at peak operating efficiency by implementing input voltage regulation (patent pending). When available solar power is inadequate to meet the power requirements of the battery charger, input voltage regulation reduces the battery charge current. This reduces the load on the solar panel to maintain the panel voltage at VMP, maximising the panel output power. This method of achieving peak panel efficiency is called maximum power point control (MPPC). While MPPC optimises solar panel efficiency during periods of low illumination, the power conversion efficiency of the battery charger suffers when power levels are low, degrading the overall power transfer efficiency from the panel to the battery. This article shows how to improve battery charger efficiency by applying a simple PWM charging technique that forces the battery charger to release energy in bursts when power levels are low. Using the Current Monitor Status Pin to Indicate Low Power Conditions The /CHRG current mon
- [13] WO2010057138A2_-_Energy-efficient_solar-powered_outdoor_lighting__593d23e6 — patent
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the charging conditions to the battery to assure that the batteries are not overcharged, preferably according to the multi-step process portrayed in Figure 40. In addition to the main steps shown in Figure 40, the multi-step process features an auto-equalize step (to 14.5V) every 28 days or if low charge, that is preferably 3 hours of over-voltage charge to reduce plate sulfation. Also, the charge controller provides for low voltage disconnect (LVD) at 11.0V (and reconnect when 12 V is again reached), to prevent damage to the batteries from over-draining. Battery charge is monitored through voltage level, as shown in Figure 41. [0212] The Inventors and Applicant use an advanced Maximum Power Point Tracking technology that converts the voltage from the solar panel that is above the battery voltage into usable energy that can be stored in the batteries. Older technologies, including PWM (pulse width modulation) charge controllers, are unable to do this. Because the batteries are a 12V system and the solar panel is a 30-33V system, significant energy can be converted from the solar panel for storage in the batteries. This enables the system to generate energy on sunny days (or even mostly-sunny days) typically well in excess of what is consumed at night. This excess is stored in the batteries. [0213] As portrayed in Figure 42, the preferred Morningstar SunSaver MPPT-15 Maximum Power Point Tracking algorithms provide 90% more efficient operation (compared to conventional PWM char
- [14] US20120020060A1_-_Energy-efficient_solar-powered_-_Google_Patents__619c8cff — patent
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accomplished, without any tie to or contribution of energy from the electrical grid, without any replacement of the batteries, and without any energy input into the batterys or any part of the lighting system except from the amorphous PV cell material on each pole. – In FIG. 50 , one may see long periods of days and weeks of sky cover (measured in hours during the day, defined as “cloudy” or “overcast” as judged from the local weather report), but the system maintained minimum battery voltage above the important benchmark of approximately 11 volts all through the roughly two month winter period, except for the “waving tree limb” incident in December, described above. InFIGS. 51A and B, which represent a different test, of a set of poles operating over about 2.5 winter months (the graph being split roughly in two), multiple poles operating independent of each other and autonomously (not tied to the grid) all performed continuously at or above 11 volts throughout the winter, despite long stretches of little or no sunshine per day. Even during the dark days of January, only a few of the poles came near to dropping to 11 volts, at which increased dimming action per the energy-savings mode E6 kept the poles operating successfully, at least at dimmed condition, during the crucual periods after dusk and before dawn, and upon motion being sensed. Up an increase in sunshine late in January, the batteries all rebounded to a range of 12-12.5 volts. – Preferred embodiments may therefore
- [15] REGULATOR_CONTROLER_SOLAR_Releu_de_arhiva_Okaziiro__a91a550e — authority
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back to normal and the load will restart working. . Thunder protection . According to the battery voltage grade, the controller can automatically set charge-off voltage, the load-off voltage, the load- restore voltage. (The parameter is default under 25℃ condition, locked by the CPU procedure, cannot adjust.) . The controller will automatically compensate the temperature of the charging voltage according to the changes of ambient temperature. Warning: Before connecting to the solar panel, please connect the controller to the battery; do not use solar panel supply power to the loads directly. Notes: Do not use lamplight to charge the solar panel (lamplight is too weak to charge) DC power source to replace the solar panel will cause troubles to controller. Choose the suitable wire which diameter should not be too small, please refer to the parameter. 4. INDICATE LIGHT AND BUTTON . When Red LED (CHARGE) is on, battery is charged up strongly; When Red LED is flickering, battery is MPPT charged up in constant voltage; when Red LED is oft charge off . When Green LED (LOAD) is on, loads are working; when Green LED (LOAD) is off, loads stop working. . Three Color-changing LED (BATTERY), When light is red, it indicates low voltage, green indicate battery full charged, orange indicate normal status. Color-changing LED working voltage indicates area: 5. PARAMETERS 6. TROUBLE SOLUTION Phenomenon:Green LED off, battery indicator LED is red. Reason: Low voltage of battery Solution: A:Cut o
- [16] WO2010057138A2_-_Energy-efficient_solar-powered_outdoor_lighting__593d23e6 — patent
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during peak electricity-usage hours, while also being capable of being autonomous (independent of the grid) operation in the event of disaster or other grid outage. In such embodiments, an inverter and control and measurement systems (G3 in Figure 18) will be added, for example, inside the pole, to cooperate with the utility grid and measure and record the system's energy contribution to the grid. [0082] Controllers are provided to manage charging of the batteries and delivery of energy to the lighting system and/or other components. Control of the operative connection between the batteries 62 and panel 14 and the operative connection between the batteries and the LED fixture 40 and other components may be done by electronics, circuitry, and/or semiconductors, for example, control board 80 shown in Figure 7. The controller(s) preferably continually monitor(s) battery voltage and temperature to determine battery health, to improve both battery performance and life. As further described later in this document, said controller(s) preferably control the speed and the amount that the batteries are charged and discharged, which can significantly affect battery life. Combined with the preferred cooling system for managing battery temperature, the batteries of the preferred embodiments are expected to exhibit longer lives, and better performance, than prior art batteries installed in solar-powered light systems. [0083] A first controller function delivers a low-current (trickle) char
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salt spray, etc. It can be easily wash with water and detergents. – Measured power generation on Inventors'/Applicant's poles according to embodiments of the invention has been measured at least 50 Watts at Boise, Id., U.S.A. during the month of November, with energy generated well in excess of 300 Watt-hours. The actual performance of the system depends on the location of the installation. Many factors influence this including shading from adjacent buildings or structures and weather patterns in the area installed. Inventors'/Applicant's preferred solar collector is currently the Unisolar PVL 136, specifications for which may be obtained from the company Unisolar and/or from appendices in the provisional U.S. application of which this application claims benefit and which are incorporated by reference into this document. – The battery charge controller is connected between the solar collector and the battery subsystem. The charge controller controls the current and voltage delivered to the batteries and optimizes the charging conditions to the battery to assure that the batteries are not overcharged, preferably according to the multi-step process portrayed in FIG. 40 . In addition to the main steps shown inFIG. 40 , the multi-step process features an auto-equalize step (to 14.5V) every 28 days or if low charge, that is preferably 3 hours of over-voltage charge to reduce plate sulfation. Also, the charge controller provides for low voltage disconnect (LVD) at 11.0V (and reconn
- [18] Solar_Charge_Controller_Improves_Efficiency_Of_Solar_Hackaday__d130cbce — authority
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# Solar Charge Controller Improves Efficiency Of Solar Panels Source: Blog/Web URL: https://hackaday.com/2015/03/17/solar-charge-controller-improves-efficiency-of-solar-panels/ Author: Bryan Cockfield Date: 2015-03-17 The simplest and easiest way to charge a battery with a solar panel is to connect the panel directly to the battery. Assuming the panel has a diode to prevent energy from flowing through it from the battery when there’s no sunlight. This is fairly common but not very efficient. [Debasish Dutta] has built a charge controller that addresses the inefficiencies of such a system though, and was able to implement maximum power point tracking using an Arduino. Maximum power point tracking (MPPT) is a method that uses PWM and a special DC-DC converter to match the impedance of the solar panel to the battery. This means that more energy can be harvested from the panel than would otherwise be available. The circuit is placed in between the panel and the battery and regulates the output voltage of the panel so it matches the voltage on the battery more closely. [Debasish] reports that an efficiency gain of 30-40% can be made with this particular design. This device has a few bells and whistles as well, including the ability to log data over WiFi, an LCD display to report the status of the panel, battery, and controller, and can charge USB devices. This would be a great addition to any solar installation, especially if you’ve built one into your truck. This is [Debasish]’s
- [19] WO2010057138A2_-_Energy-efficient_solar-powered_outdoor_lighting__593d23e6 — patent
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a different test, of a set of poles operating over about 2.5 winter months (the graph being split roughly in two), multiple poles operating independent of each other and autonomously (not tied to the grid) all performed continuously at or above 1 1 volts throughout the winter, despite long stretches of little or no sunshine per day. – a solar- powered outdoor lighting system comprising: a flexible photovoltaic solar collector panel curved at least 180 degrees around a generally cylindrical light pole and attached to the light pole so that the panel is generally vertical; a lighting fixture connected to the pole and comprising multiple light emitting diodes (LEDs); at least one battery operatively connected to the solar collector panel and the LEDs; an active controller system comprising a maximum power point tracking charge controller adapted to charge said at least one battery, and a load controller adapted for management of energy delivery to said LEDs, wherein said management of energy delivery is adapted to turn on, turn off, dim and brighten said LEDs; at least one motion sensor connected to said pole and operatively connected to said load controller; wherein said load controller is adapted, in response to said motion sensor sensing motion near the pole when the LEDs are in a dimmed state, to increase power to said LEDs to brighten said LEDs at least while said motion is detected. – LEDs light emitting diodes – Said active controller may be adapted to dim said LEDs when
- [22] How_to_select_a_solar_charge_controller_for_your_PV_system__97277523 — magazine
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for the connected DC electrical loads is very important. The low voltage disconnect (LVD) switching included with a charge controller protects batteries from over-discharging. Overcharging all types of batteries can cause irreparable damage. Overcharging lead-acid batteries may cause excessive gassing that can actually “boil” the water away, damaging a battery’s plates by exposing them. In a worst-case scenario, overheating and high pressure can cause explosive results upon release. Typically, smaller charge controllers include a load control circuit. On larger controllers such as the Morningstar TriStar, separate load control switches and relays can also be used for load control of DC loads up to 45 or 60 Amps. Alongside a charge controller, a relay driver is also commonly used to switch relays on and off for load control. The relay driver includes four separate channels to prioritize more critical loads to stay on longer than less critical loads. It’s also useful for automatic generator start control and alarm notifications. More advanced solar charge controllers can also monitor temperature and adjust battery charging to optimize the charging accordingly. This is referred to as temperature compensation, which charges to a higher voltage in cold temperatures and a lower voltage when it is warm. Many solar charge controllers include on-site and remote data monitoring. Morningstar offers serial communications options so the controllers can be monitored locally or remotely wit
- [23] How_to_select_a_solar_charge_controller_for_your_PV_system__97277523 — authority
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for the connected DC electrical loads is very important. The low voltage disconnect (LVD) switching included with a charge controller protects batteries from over-discharging. Overcharging all types of batteries can cause irreparable damage. Overcharging lead-acid batteries may cause excessive gassing that can actually “boil” the water away, damaging a battery’s plates by exposing them. In a worst-case scenario, overheating and high pressure can cause explosive results upon release. Typically, smaller charge controllers include a load control circuit. On larger controllers such as the Morningstar TriStar, separate load control switches and relays can also be used for load control of DC loads up to 45 or 60 Amps. Alongside a charge controller, a relay driver is also commonly used to switch relays on and off for load control. The relay driver includes four separate channels to prioritize more critical loads to stay on longer than less critical loads. It’s also useful for automatic generator start control and alarm notifications. More advanced solar charge controllers can also monitor temperature and adjust battery charging to optimize the charging accordingly. This is referred to as temperature compensation, which charges to a higher voltage in cold temperatures and a lower voltage when it is warm. Many solar charge controllers include on-site and remote data monitoring. Morningstar offers serial communications options so the controllers can be monitored locally or remotely wit
- [24] US5703468A_-_Electrical_charge_control_apparatus_-_Google_Patents__9e2c41a8 — patent
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in low earth orbit spacecraft applications, according to which battery charging is terminated when the battery temperature starts to increase following a decrease at the end of charge. – Canadian Patent 1,162,607 and European Patent 342,578 provide disclosures which are based on extensions of the shunt control method of photovoltaic battery charge regulation. – Canadian Patent 1,162,607 there is provided an apparatus which selectively includes portions of the photovoltaic array, or alternatively shunts portions of the photovoltaic array, to provide appropriate charging voltage to the storage batteries. – the photovoltaic array is electrically subdivided into subarrays which are sequentially removed from, or included in, the charging circuit, based on the measured terminal voltage of the battery. – European Patent 342,578 discloses a charge control apparatus and method comprising one or more subarrays of photovoltaic panels connected in series, wherein a fixed portion of the subarray is shunted or alternatively contributing to battery charging, depending on measured battery potential compared to predefined voltage setpoints. – a method of charge control for rechargeable batteries which comprises the electrical connection of one or more voltage setpoint control terminations to one of three electrical potential contacts, each connection thus executed resulting in a specific and predefined charge voltage setpoint condition for charge terminate voltage threshold and charge resume
# Solar Basics (At Home!): What are solar charge controllers? Source: YouTube — Solar Power World URL: https://www.youtube.com/watch?v=iOqJvWRyxSA Video ID: iOqJvWRyxSA Transcript: generated welcome to solar basics i'm kelsey misbrenner senior editor of solar power world and i'm kelly pickerel editor-in-chief customers who want a hybrid solar plus storage system that can sell solar generated electricity during the day and store that power for use at night during an outage or during peak times we'll need a solar charge controller charge controllers are the regulators of solar plus storage systems they deliver power from the pv array to system loads and the battery bank when the battery bank is nearly full the controller will taper off the charging current to maintain the required voltage to fully charge the battery and keep it topped off by being able to regulate the voltage the solar controller protects the battery batteries can be the most expensive part of the system and a solar charge controller protects them from both overcharging and under charging extended periods with a partial state of charge will cause the plates of a lead acid battery to become sulfated and greatly reduce life expectancy lithium battery chemistries are equally vulnerable to chronic undercharging running batteries down to zero can kill them quickly overcharging all types of batteries can cause irreparable damage overcharging lead acid batteries may cause excessive gassing that can actually boil the w
and which are incorporated by reference into this document. – the battery charge controller is connected between the solar collector and the battery subsystem. – the charge controller controls the current and voltage delivered to the batteries and optimizes the charging conditions to the battery to assure that the batteries are not overcharged, preferably according to the multi-step process portrayed in Figure 40. – the multi-step process features an auto-equalize step (to 14.5V) every 28 days or if low charge, that is preferably 3 hours of over-voltage charge to reduce plate sulfation. – the charge controller provides for low voltage disconnect (LVD) at 11.0V (and reconnect when 12 V is again reached), to prevent damage to the batteries from over-draining. Battery charge is monitored through voltage level, as shown in Figure 41. – the Inventors and Applicant use an advanced Maximum Power Point Tracking technology that converts the voltage from the solar panel that is above the battery voltage into usable energy that can be stored in the batteries. Older technologies, including PWM (pulse width modulation) charge controllers, are unable to do this. Because the batteries are a 12V system and the solar panel is a 30-33V system, significant energy can be converted from the solar panel for storage in the batteries. This enables the system to generate energy on sunny days (or even mostly-sunny days) typically well in excess of what is consumed at night. This excess is stored in th
# How to select a solar charge controller for your PV system Source: Blog/Web URL: https://www.solarpowerworldonline.com/2019/12/how-to-select-a-solar-charge-controller/ Author: SPW Date: 2019-12-10 By Douglas Grubbs, applications engineer, Morningstar Corporation In its basic forms, solar PV is a very straightforward proposition. Hook a solar panel up to a DC load and it will run until the sun goes down. Connect solar panels to a grid-tied inverter and, as long as the sun is shining, power will be sent to the utility. It’s all fairly easy — until the sun stops shining. Where it starts to get more complex is with energy storage, for use when the sun isn’t shining or when the grid is down. Storing electricity to do useful work later requires batteries connected to a solar PV system. Once a battery is added, a charge controller becomes one of the most important system components. Anyone going off-grid or wanting to use a hybrid system that can sell solar-generated electricity during the day and store that power for use at night, during an outage or during peak times will need a solar charge controller. What a solar charge controller does Think of a solar charge controller as a regulator. It delivers power from the PV array to system loads and the battery bank. When the battery bank is nearly full, the controller will taper off the charging current to maintain the required voltage to fully charge the battery and keep it topped off. By being able to regulate the voltage, the sola
# How to select a solar charge controller for your PV system Source: Blog/Web URL: https://www.solarpowerworldonline.com/2019/12/how-to-select-a-solar-charge-controller/ Author: SPW Date: 2019-12-10 By Douglas Grubbs, applications engineer, Morningstar Corporation In its basic forms, solar PV is a very straightforward proposition. Hook a solar panel up to a DC load and it will run until the sun goes down. Connect solar panels to a grid-tied inverter and, as long as the sun is shining, power will be sent to the utility. It’s all fairly easy — until the sun stops shining. Where it starts to get more complex is with energy storage, for use when the sun isn’t shining or when the grid is down. Storing electricity to do useful work later requires batteries connected to a solar PV system. Once a battery is added, a charge controller becomes one of the most important system components. Anyone going off-grid or wanting to use a hybrid system that can sell solar-generated electricity during the day and store that power for use at night, during an outage or during peak times will need a solar charge controller. What a solar charge controller does Think of a solar charge controller as a regulator. It delivers power from the PV array to system loads and the battery bank. When the battery bank is nearly full, the controller will taper off the charging current to maintain the required voltage to fully charge the battery and keep it topped off. By being able to regulate the voltage, the sola
# What is a solar charge controller? Source: Blog/Web URL: https://www.solarpowerworldonline.com/2015/07/what-is-a-charge-controllers-function/ Author: Joshua Smalley; Intern; SPW Date: 2015-07-20 Any system with energy storage needs a way to regulate the flow of energy into the batteries. Philip Undercuffler, director of strategic platforms at OutBack Power, said that regulation prevents the batteries from overcharging and potentially receiving damage. “Solar charge controllers regulate the energy flowing from the PV array and transfer it directly to the batteries as a DC-coupled system, which is the most efficient and effective manner,” he said. Giving batteries as long of a life as possible is an important function of a charge controller. Two different types of charge controllers exist for solar systems. The first, which Undercuffler simply referred to as the “standard,” is usually small and commonly features pulse-width modulation (PWM). “The PWM controllers are old school and not very efficient,” said Bob Gudgel and Kim Silva of MidNite Solar. PWM technology sends out short controlling pulses to the batteries and is not particularly agile. It lacks the ability to optimize an entire array based on differences between panels, for example. PWM is adequate in places with constant, steady and strong solar radiation and in systems that are cost-sensitive, according to Undercuffler. The second and most common type of controller has maximum power point tracking (MPPT) technology
# What is a solar charge controller? Source: Blog/Web URL: https://www.solarpowerworldonline.com/2015/07/what-is-a-charge-controllers-function/ Author: Joshua Smalley; Intern; SPW Date: 2015-07-20 Any system with energy storage needs a way to regulate the flow of energy into the batteries. Philip Undercuffler, director of strategic platforms at OutBack Power, said that regulation prevents the batteries from overcharging and potentially receiving damage. “Solar charge controllers regulate the energy flowing from the PV array and transfer it directly to the batteries as a DC-coupled system, which is the most efficient and effective manner,” he said. Giving batteries as long of a life as possible is an important function of a charge controller. Two different types of charge controllers exist for solar systems. The first, which Undercuffler simply referred to as the “standard,” is usually small and commonly features pulse-width modulation (PWM). “The PWM controllers are old school and not very efficient,” said Bob Gudgel and Kim Silva of MidNite Solar. PWM technology sends out short controlling pulses to the batteries and is not particularly agile. It lacks the ability to optimize an entire array based on differences between panels, for example. PWM is adequate in places with constant, steady and strong solar radiation and in systems that are cost-sensitive, according to Undercuffler. The second and most common type of controller has maximum power point tracking (MPPT) technology
is broken at preselected intervals to permit the voltage levels of the panel and battery to be tested. The ratio of the voltages is used to determine if a direct connection should be reestablished, or trickle charging through the float regulator should occur. U.S. Pat. No. 4,401,935 discloses an apparatus and method for controlling the charging of a rechargeable battery by a photovoltaic panel and discharging the battery through a lead, in which a relay is switched between a first condition coupling of the battery to the lead and a float regulator, and a second condition coupling of the battery directly to the panel. Exemplary photovoltaic charging systems which employ temperature compensated charging regulation may be found in U.S. Pat. No. 4,349,775 and U.S. Pat. No. 4,622,509. In U.S. Pat. No. 4,349,775, there is provided means for automatic adjustment of the regulator's reference potential in response to monitored temperature changes, thereby providing temperature compensation of the maximum charging voltage and improved protection of the system battery. U.S. Pat. No. 4,622,509 discloses a method and circuit for Ni-Cd battery charge control in low earth orbit spacecraft applications, according to which battery charging is terminated when the battery temperature starts to increase following a decrease at the end of charge. Canadian Patent 1,162,607 and European Patent 342,578 provide disclosures which are based on extensions of the shunt control method of photovoltaic batt
it is discovered that in the latest unit time interval there are severe or violent weather changes, it is determined that the battery is not adapted to be charged. – the latest weather change conditions such as the ambient temperature, the illuminance and the like – the maximum power point voltage is generally low on cloudy days, the maximum power point voltage cannot match the desired battery charging voltage even though the number of series-connected photovoltaic panels is adjusted to a maximum value, whereupon the secondary battery is not adapted to be directly charged, and the reminding information is triggered to be generated and displayed. – step S 2 judging whether the target number of series-connected photovoltaic panels is equal to the current number of series-connected photovoltaic panels, if YES, executing step S 4 , otherwise, executing step S 3 . – step S 2 for example, if the target number of series-connected photovoltaic panels is 6 and the current number of series-connected photovoltaic panels is also 6 , it is not necessary to adjust the number of series-connected photovoltaic panels of each of the photovoltaic panel series branches, and the process may jump to step S 3 , otherwise performing step S 3 to adjust the number of series-connected photovoltaic panels of each of the photovoltaic panel series branches. – step S 3 generating a first control signal according to the target number of series-connected photovoltaic panels, and transmitting the first contro
# How to use solar power to charge batteries efficiently | Electronics Weekly Source: Blog/Web URL: https://www.electronicsweekly.com/market-sectors/power/use-solar-power-charge-batteries-efficiently-2014-03/ Author: Richard Wilson Date: 2014-03-10 An important characteristic of any solar panel is that it achieves peak power output at a relatively constant operating voltage (VMP) regardless of illumination level. The LT3652 2A battery charger is designed to exploit this characteristic to maintain a solar panel at peak operating efficiency by implementing input voltage regulation (patent pending). When available solar power is inadequate to meet the power requirements of the battery charger, input voltage regulation reduces the battery charge current. This reduces the load on the solar panel to maintain the panel voltage at VMP, maximising the panel output power. This method of achieving peak panel efficiency is called maximum power point control (MPPC). While MPPC optimises solar panel efficiency during periods of low illumination, the power conversion efficiency of the battery charger suffers when power levels are low, degrading the overall power transfer efficiency from the panel to the battery. This article shows how to improve battery charger efficiency by applying a simple PWM charging technique that forces the battery charger to release energy in bursts when power levels are low. Using the Current Monitor Status Pin to Indicate Low Power Conditions The /CHRG current mon
# How to use solar power to charge batteries efficiently | Electronics Weekly Source: Blog/Web URL: https://www.electronicsweekly.com/market-sectors/power/use-solar-power-charge-batteries-efficiently-2014-03/ Author: Richard Wilson Date: 2014-03-10 An important characteristic of any solar panel is that it achieves peak power output at a relatively constant operating voltage (VMP) regardless of illumination level. The LT3652 2A battery charger is designed to exploit this characteristic to maintain a solar panel at peak operating efficiency by implementing input voltage regulation (patent pending). When available solar power is inadequate to meet the power requirements of the battery charger, input voltage regulation reduces the battery charge current. This reduces the load on the solar panel to maintain the panel voltage at VMP, maximising the panel output power. This method of achieving peak panel efficiency is called maximum power point control (MPPC). While MPPC optimises solar panel efficiency during periods of low illumination, the power conversion efficiency of the battery charger suffers when power levels are low, degrading the overall power transfer efficiency from the panel to the battery. This article shows how to improve battery charger efficiency by applying a simple PWM charging technique that forces the battery charger to release energy in bursts when power levels are low. Using the Current Monitor Status Pin to Indicate Low Power Conditions The /CHRG current mon
the charging conditions to the battery to assure that the batteries are not overcharged, preferably according to the multi-step process portrayed in Figure 40. In addition to the main steps shown in Figure 40, the multi-step process features an auto-equalize step (to 14.5V) every 28 days or if low charge, that is preferably 3 hours of over-voltage charge to reduce plate sulfation. Also, the charge controller provides for low voltage disconnect (LVD) at 11.0V (and reconnect when 12 V is again reached), to prevent damage to the batteries from over-draining. Battery charge is monitored through voltage level, as shown in Figure 41. [0212] The Inventors and Applicant use an advanced Maximum Power Point Tracking technology that converts the voltage from the solar panel that is above the battery voltage into usable energy that can be stored in the batteries. Older technologies, including PWM (pulse width modulation) charge controllers, are unable to do this. Because the batteries are a 12V system and the solar panel is a 30-33V system, significant energy can be converted from the solar panel for storage in the batteries. This enables the system to generate energy on sunny days (or even mostly-sunny days) typically well in excess of what is consumed at night. This excess is stored in the batteries. [0213] As portrayed in Figure 42, the preferred Morningstar SunSaver MPPT-15 Maximum Power Point Tracking algorithms provide 90% more efficient operation (compared to conventional PWM char
accomplished, without any tie to or contribution of energy from the electrical grid, without any replacement of the batteries, and without any energy input into the batterys or any part of the lighting system except from the amorphous PV cell material on each pole. – In FIG. 50 , one may see long periods of days and weeks of sky cover (measured in hours during the day, defined as “cloudy” or “overcast” as judged from the local weather report), but the system maintained minimum battery voltage above the important benchmark of approximately 11 volts all through the roughly two month winter period, except for the “waving tree limb” incident in December, described above. InFIGS. 51A and B, which represent a different test, of a set of poles operating over about 2.5 winter months (the graph being split roughly in two), multiple poles operating independent of each other and autonomously (not tied to the grid) all performed continuously at or above 11 volts throughout the winter, despite long stretches of little or no sunshine per day. Even during the dark days of January, only a few of the poles came near to dropping to 11 volts, at which increased dimming action per the energy-savings mode E6 kept the poles operating successfully, at least at dimmed condition, during the crucual periods after dusk and before dawn, and upon motion being sensed. Up an increase in sunshine late in January, the batteries all rebounded to a range of 12-12.5 volts. – Preferred embodiments may therefore
back to normal and the load will restart working. . Thunder protection . According to the battery voltage grade, the controller can automatically set charge-off voltage, the load-off voltage, the load- restore voltage. (The parameter is default under 25℃ condition, locked by the CPU procedure, cannot adjust.) . The controller will automatically compensate the temperature of the charging voltage according to the changes of ambient temperature. Warning: Before connecting to the solar panel, please connect the controller to the battery; do not use solar panel supply power to the loads directly. Notes: Do not use lamplight to charge the solar panel (lamplight is too weak to charge) DC power source to replace the solar panel will cause troubles to controller. Choose the suitable wire which diameter should not be too small, please refer to the parameter. 4. INDICATE LIGHT AND BUTTON . When Red LED (CHARGE) is on, battery is charged up strongly; When Red LED is flickering, battery is MPPT charged up in constant voltage; when Red LED is oft charge off . When Green LED (LOAD) is on, loads are working; when Green LED (LOAD) is off, loads stop working. . Three Color-changing LED (BATTERY), When light is red, it indicates low voltage, green indicate battery full charged, orange indicate normal status. Color-changing LED working voltage indicates area: 5. PARAMETERS 6. TROUBLE SOLUTION Phenomenon:Green LED off, battery indicator LED is red. Reason: Low voltage of battery Solution: A:Cut o
during peak electricity-usage hours, while also being capable of being autonomous (independent of the grid) operation in the event of disaster or other grid outage. In such embodiments, an inverter and control and measurement systems (G3 in Figure 18) will be added, for example, inside the pole, to cooperate with the utility grid and measure and record the system's energy contribution to the grid. [0082] Controllers are provided to manage charging of the batteries and delivery of energy to the lighting system and/or other components. Control of the operative connection between the batteries 62 and panel 14 and the operative connection between the batteries and the LED fixture 40 and other components may be done by electronics, circuitry, and/or semiconductors, for example, control board 80 shown in Figure 7. The controller(s) preferably continually monitor(s) battery voltage and temperature to determine battery health, to improve both battery performance and life. As further described later in this document, said controller(s) preferably control the speed and the amount that the batteries are charged and discharged, which can significantly affect battery life. Combined with the preferred cooling system for managing battery temperature, the batteries of the preferred embodiments are expected to exhibit longer lives, and better performance, than prior art batteries installed in solar-powered light systems. [0083] A first controller function delivers a low-current (trickle) char
salt spray, etc. It can be easily wash with water and detergents. – Measured power generation on Inventors'/Applicant's poles according to embodiments of the invention has been measured at least 50 Watts at Boise, Id., U.S.A. during the month of November, with energy generated well in excess of 300 Watt-hours. The actual performance of the system depends on the location of the installation. Many factors influence this including shading from adjacent buildings or structures and weather patterns in the area installed. Inventors'/Applicant's preferred solar collector is currently the Unisolar PVL 136, specifications for which may be obtained from the company Unisolar and/or from appendices in the provisional U.S. application of which this application claims benefit and which are incorporated by reference into this document. – The battery charge controller is connected between the solar collector and the battery subsystem. The charge controller controls the current and voltage delivered to the batteries and optimizes the charging conditions to the battery to assure that the batteries are not overcharged, preferably according to the multi-step process portrayed in FIG. 40 . In addition to the main steps shown inFIG. 40 , the multi-step process features an auto-equalize step (to 14.5V) every 28 days or if low charge, that is preferably 3 hours of over-voltage charge to reduce plate sulfation. Also, the charge controller provides for low voltage disconnect (LVD) at 11.0V (and reconn
# Solar Charge Controller Improves Efficiency Of Solar Panels Source: Blog/Web URL: https://hackaday.com/2015/03/17/solar-charge-controller-improves-efficiency-of-solar-panels/ Author: Bryan Cockfield Date: 2015-03-17 The simplest and easiest way to charge a battery with a solar panel is to connect the panel directly to the battery. Assuming the panel has a diode to prevent energy from flowing through it from the battery when there’s no sunlight. This is fairly common but not very efficient. [Debasish Dutta] has built a charge controller that addresses the inefficiencies of such a system though, and was able to implement maximum power point tracking using an Arduino. Maximum power point tracking (MPPT) is a method that uses PWM and a special DC-DC converter to match the impedance of the solar panel to the battery. This means that more energy can be harvested from the panel than would otherwise be available. The circuit is placed in between the panel and the battery and regulates the output voltage of the panel so it matches the voltage on the battery more closely. [Debasish] reports that an efficiency gain of 30-40% can be made with this particular design. This device has a few bells and whistles as well, including the ability to log data over WiFi, an LCD display to report the status of the panel, battery, and controller, and can charge USB devices. This would be a great addition to any solar installation, especially if you’ve built one into your truck. This is [Debasish]’s
a different test, of a set of poles operating over about 2.5 winter months (the graph being split roughly in two), multiple poles operating independent of each other and autonomously (not tied to the grid) all performed continuously at or above 1 1 volts throughout the winter, despite long stretches of little or no sunshine per day. – a solar- powered outdoor lighting system comprising: a flexible photovoltaic solar collector panel curved at least 180 degrees around a generally cylindrical light pole and attached to the light pole so that the panel is generally vertical; a lighting fixture connected to the pole and comprising multiple light emitting diodes (LEDs); at least one battery operatively connected to the solar collector panel and the LEDs; an active controller system comprising a maximum power point tracking charge controller adapted to charge said at least one battery, and a load controller adapted for management of energy delivery to said LEDs, wherein said management of energy delivery is adapted to turn on, turn off, dim and brighten said LEDs; at least one motion sensor connected to said pole and operatively connected to said load controller; wherein said load controller is adapted, in response to said motion sensor sensing motion near the pole when the LEDs are in a dimmed state, to increase power to said LEDs to brighten said LEDs at least while said motion is detected. – LEDs light emitting diodes – Said active controller may be adapted to dim said LEDs when
for the connected DC electrical loads is very important. The low voltage disconnect (LVD) switching included with a charge controller protects batteries from over-discharging. Overcharging all types of batteries can cause irreparable damage. Overcharging lead-acid batteries may cause excessive gassing that can actually “boil” the water away, damaging a battery’s plates by exposing them. In a worst-case scenario, overheating and high pressure can cause explosive results upon release. Typically, smaller charge controllers include a load control circuit. On larger controllers such as the Morningstar TriStar, separate load control switches and relays can also be used for load control of DC loads up to 45 or 60 Amps. Alongside a charge controller, a relay driver is also commonly used to switch relays on and off for load control. The relay driver includes four separate channels to prioritize more critical loads to stay on longer than less critical loads. It’s also useful for automatic generator start control and alarm notifications. More advanced solar charge controllers can also monitor temperature and adjust battery charging to optimize the charging accordingly. This is referred to as temperature compensation, which charges to a higher voltage in cold temperatures and a lower voltage when it is warm. Many solar charge controllers include on-site and remote data monitoring. Morningstar offers serial communications options so the controllers can be monitored locally or remotely wit
for the connected DC electrical loads is very important. The low voltage disconnect (LVD) switching included with a charge controller protects batteries from over-discharging. Overcharging all types of batteries can cause irreparable damage. Overcharging lead-acid batteries may cause excessive gassing that can actually “boil” the water away, damaging a battery’s plates by exposing them. In a worst-case scenario, overheating and high pressure can cause explosive results upon release. Typically, smaller charge controllers include a load control circuit. On larger controllers such as the Morningstar TriStar, separate load control switches and relays can also be used for load control of DC loads up to 45 or 60 Amps. Alongside a charge controller, a relay driver is also commonly used to switch relays on and off for load control. The relay driver includes four separate channels to prioritize more critical loads to stay on longer than less critical loads. It’s also useful for automatic generator start control and alarm notifications. More advanced solar charge controllers can also monitor temperature and adjust battery charging to optimize the charging accordingly. This is referred to as temperature compensation, which charges to a higher voltage in cold temperatures and a lower voltage when it is warm. Many solar charge controllers include on-site and remote data monitoring. Morningstar offers serial communications options so the controllers can be monitored locally or remotely wit
in low earth orbit spacecraft applications, according to which battery charging is terminated when the battery temperature starts to increase following a decrease at the end of charge. – Canadian Patent 1,162,607 and European Patent 342,578 provide disclosures which are based on extensions of the shunt control method of photovoltaic battery charge regulation. – Canadian Patent 1,162,607 there is provided an apparatus which selectively includes portions of the photovoltaic array, or alternatively shunts portions of the photovoltaic array, to provide appropriate charging voltage to the storage batteries. – the photovoltaic array is electrically subdivided into subarrays which are sequentially removed from, or included in, the charging circuit, based on the measured terminal voltage of the battery. – European Patent 342,578 discloses a charge control apparatus and method comprising one or more subarrays of photovoltaic panels connected in series, wherein a fixed portion of the subarray is shunted or alternatively contributing to battery charging, depending on measured battery potential compared to predefined voltage setpoints. – a method of charge control for rechargeable batteries which comprises the electrical connection of one or more voltage setpoint control terminations to one of three electrical potential contacts, each connection thus executed resulting in a specific and predefined charge voltage setpoint condition for charge terminate voltage threshold and charge resume