Solar Charge Controllers

The charge controller is a key component of a solar power system and specifying the best one for the system requires some analysis.

The two types of charge controllers most commonly used in today’s solar power systems are pulse width modulation (PWM) and maximum power point tracking (MPPT). Both adjust charging rates depending on the battery's charge level to allow charging closer to the battery’s maximum capacity as well as monitor battery temperature to prevent overheating.

In solar power system, charge controller is the heart of the system which was designed to protect the rechargeable battery.

The PWM controller is in essence a switch that connects a solar array to the battery. The result is that the voltage of the array will be pulled down to near that of the battery.

A solar charge controller regulates the voltage and current coming from your solar panels which is placed between a solar panel and a battery .It is used to maintain the proper charging voltage on the batteries. As the input voltage from the solar panel rises, the charge controller regulates the charge to the batteries preventing any overcharging.

Pulse Width Modulation (PWM) is the most effective means to achieve constant voltage battery charging by adjusting the duty ratio of the switches ( MOSFET ). In PWM charge controller, the current from the solar panel tapers according to the battery’s condition and recharging needs. When a battery voltage reaches the regulation set point, the PWM algorithm slowly reduces the charging current to avoid heating and gassing of the battery, yet the charging continues to return the maximum amount of energy to the battery in the shortest time.

  • PWM 12V, (3 – 60)A Charge Controller
  • PWM 24V, (3 – 60)A Charge Controller
  • PWM 36V, (10 – 60)A Charge Controller
  • PWM 48V, (10 – 80)A Charge Controller
  • PWM 96V, (10 – 80)A Charge Controller
  • PWM 120V, (10 – 80)A Charge Controller
  • PWM 240V, (10 – 80)A Charge Controller
  • PWM 360V, (10 – 80)A Charge Controller
  • Higher charging efficiency
  • Longer battery life
  • Reduce battery over heating
  • Minimizes stress on the battery
  • Ability to isolate a battery




 Min PV Input Voltage    14.5V  28.0V
 Max PV Input Voltage   25.0V  50.0V
 Operating Voltage   12.0V   24.0V 
Grid Stop Charging Voltage   13.6V   27.6V
 Grid Start Charging Voltage     11.6V  23.2V
 Low Voltage Battery Cut-Off    10.5V  21.0V
 Rated Current  10A - 50A
 LCD Display (Optional)   V, I of Solar PV and Battery, Solar Power & Energy
 MPPT   Yes

1. Battery Over Voltage/Current

2. Battery & Panel Reverse Protection

GEESYS MPPT solar controller with Microcontroller technology is an advanced maximum power point tracking (MPPT) battery charger for off-grid photovoltaic(PV) systems. The controller features a smart tracking algorithm that maximizes the energy harvest from the PV and also provides load control to prevent over discharge of the battery.

The GEESYS MPPT is well suited for both professional and consumer PV applications including automatic lighting control. Its charging process has been optimized for long battery life and improved system performance. This product is epoxy encapsulated for environmental protection, may be adjusted by the user via four settings switches or connection to a personal computer, and has an optional remote meter and battery temperature sensor.

The MPPT controller is more sophisticated (and more expensive): it will adjust its input voltage to harvest the maximum power from the solar array and then transform this power to supply the varying voltage requirement, of the battery plus load. Thus, it essentially decouples the array and battery voltages so that there can be, for example, a 12 volt battery on one side of the MPPT charge controller and a large number of cells wired in series to produce 36 volts on the other.

To fully exploit the potential of the MPPT controller, the array voltage should be substantially higher than the battery voltage. The MPPT controller is the solution of choice for higher power systems (because of the lowest overall system cost due to smaller cable cross sectional areas). The MPPT controller will also harvest substantially more power when the solar cell temperature is low (below 45°C), or very high (above 75°C), or when irradiance is very low.

  • MPPT 12V, (3 – 60)A Charge Controller
  • MPPT 24V, (3 – 60)A Charge Controller
  • MPPT 36V, (10 – 60)A Charge Controller
  • MPPT 48V, (10 – 80)A Charge Controller
  • MPPT 96V, (10 – 80)A Charge Controller
  • MPPT 120V, (10 – 80)A Charge Controller
  • MPPT 240V, (10 – 80)A Charge Controller
  • MPPT 360V, (10 – 80)A Charge Controller
  • Auto input PV – VMP tracking
  • DSP based controlled algorism
  • Single card state – of - the
  • Wide PV input voltage range
  • User friendly LCD displays for all parameters
  • Temp compensation for charging
  • Up to 30% extra power as compared to PWM
  • Rs232 for external communication
  • Maximum Power Point Tracking : The MPPT controller will harvest more power from the solar array. The performance advantage is substantial (10% to 40%) when the solar cell temperature is low (below 45°C), or very high (above 75°C),or when irradiance is very low.At high temperature or low irradiance the output voltage of the array will drop dramatically. More cells must then be connected in series to make sure that the output voltage of the array exceeds battery voltage by a comfortable margin.
  • Lower cabling cost and/or lower cabling losses: Ohm’s law tells us that losses due to cable resistance are Pc (Watt) = Rc x I², where Rc is the resistance of the cable. What this formula shows is that for a given cable loss, cable cross sectional area can be reduced by a factor of four when doubling the array voltage.
    In the case of a given nominal power, more cells in series will increase the output voltage and reduce the output current of the array (P = V x I, thus, if P doesn’t change, then I must decrease when V increases).
    As array size increases, cable length will increase. The option to wire more panels in series and thereby decrease the cable cross sectional area with a resultant drop in cost, is a compelling reason to install an MPPT controller as soon as the array power exceeds a few hundred Watts (12 V battery), or several 100s of Watts (24 V or 48 V battery).
  • MPPT controllers offer a potential increase in charging efficiency up to 30% (Maximizes energy harvest)
  • These controllers also offer the potential ability to have an array with higher input voltage than the battery bank
  • You can get sizes up to 80 Amps
  • MPPT controller warranties are typically longer than PWM units
  • MPPT offer great flexibility for system growth
  • Longer Battery life
  • Extensive electronic Protections
  • Fully adjustable and highly reliable
  • MCU based buck converter 12/24Volt 20/40A.
  • MPPT Technology, efficiency improved by more than 20%.
  • First in its class LCD with Power and Energy measurement.
  • Menu settable configuration using 2x16 LCD and 3 push buttons.
  • Menu settable Battery voltage, battery current , Float voltage and Float current.
  • Three stage Charging.
  • Over voltage/Over current protection.
  • Optional relays to control Mains charger and Inverter.
  • Lower System Cost






 BATTERY INPUT  12V  24V  24V  48V  48V  48V
 ARRAY INPUT RANGE  25 - 50Vdc  45 - 100Vdc  45 - 100Vdc  60 - 150Vdc  60 - 150Vdc  60 - 150Vds
 MAX PV ARRAY CAPACITY   500W  1000W 2000W  3000W 
 RECOMMENDED PV PANEL TYPE  250Wx2  250Wx4  250Wx8   250Wx12 
 WEIGHT  1.5Kg   1.7Kg  2.5Kg   2.5Kg
 DIMENSION    185X140x90mm (HxWxL)  250x175x100mm (HxWxL)