MPPT Solar Panel 12V Battery Charge Board

MPPT Solar Panel 12V Battery Charge Board CN3767

13,5V 3A Battery Lead Acid Accumulator Charge Solar Cell Deep Charge

     This board charges a 12V lead acid battery with energy from an 18V solar panel and has MPPT (maximum power point tracking). It carries the CN3767 charge IC; with enough sunlight it charges the battery with up to 3A. When the battery is full it lowers the charge voltage to the 13.55V float level, and when the battery voltage drops it restarts charging automatically.

     Using the constant voltage method, the CN3767 keeps the panel voltage close to the point where the panel delivers the most power, so more energy is taken from the panel in cloudy weather or when light changes. Charging runs in stages: low current precharge for a deeply discharged battery, constant current, 14.8V constant voltage and 13.55V float. The 50mm x 33mm red board has solder holes for the panel input (SOLAR INPUT +/-) and battery output (+BAT/-), two status LEDs and mounting holes in three corners (the hole in the fourth corner is the panel + input).

     It is suitable for keeping the battery charged by the sun in off-grid 12V systems such as garden lighting, security cameras, irrigation pumps, caravan and boat batteries. At charge currents above 2A the board must be cooled (see Usage information below).

Key features:

     More energy with MPPT: The CN3767 keeps the panel voltage near the maximum power point; as panel current and voltage change, more energy reaches the battery than with the panel connected directly to the battery.

     Charge stages for lead acid batteries: A deeply discharged battery is first charged with low current, then filled with constant current and 14.8V constant voltage; when full it is held at the 13.55V float voltage.

     Up to 3A charge current: With enough sunlight it charges the battery with up to 3A. Above 2A the board must be cooled with an aluminium plate underneath.

     Automatic operation: No adjustment needed; charging starts when sunlight arrives, switches to float when the battery is full and restarts when the battery voltage drops.

     Small board, two status LEDs: 50mm x 33mm in size and 13gr in weight; the red and green LEDs show panel energy and charge status.

Features:

• Product type: MPPT solar panel charge board for 12V lead acid batteries
• Charge IC: CN3767 (lead acid battery charge IC with MPPT)
• Battery type: 12V lead acid battery (6 cells)
• Solar panel: 18V nominal panel (panel made for 12V systems)
• Panel input voltage upper limit: 30V (panel open circuit voltage must not exceed this value)
• Charge current: up to 3A (with enough sunlight); cooling required above 2A
• Constant voltage stage charge voltage: 14.8V
• Float charge voltage: 13.55V
• MPPT: Constant voltage maximum power point tracking; about 10-30% more energy than PWM charge boards
• Charge stages: Precharge (trickle) for a deeply discharged battery, constant current, constant voltage, float
• Automatic recharge: Charging restarts by itself when the battery voltage drops
• Battery overcharge protection: Yes
• Soft start: Yes
• Switching frequency: 300kHz
• Status indicator: 2 LEDs (red: panel energy / charging, green: battery full or no battery connected)
• Connection: Solder holes for panel input (SOLAR INPUT +/-) and battery output (+BAT/-)
• Code on the board: HW-845
• Operating temperature: -10°C - 85°C
• Material and colour: Red PCB, mounting hole in 3 corners
• Dimensions: 50mm x 33mm x 18mm
• Weight: 13gr

Usage information:

• Solder the solar panel + lead to the SOLAR INPUT + hole and the - lead to SOLAR INPUT -; solder the battery + lead to the +BAT hole and the - lead to the - hole on the lower edge of the board, using wire thick enough for the current. Do not reverse the polarity.
• When energy comes from the panel the red LED lights. When the panel voltage exceeds 15V the green LED lights and, with no battery connected, 13.5V can be measured at the output; this shows the charge circuit is working (robiz test). With a battery connected, the red LED lights while charging and the green LED lights when the battery is full.
• At charge currents above 2A, place an aluminium plate under the board, keeping it insulated, so the board passes its heat to the plate.
• The main job of the board is charging a 12V battery. In sunny weather a 12V device can also be run directly for a moment; we tested this by running a 12V motor. Since the panel current depends on sunlight, supply your devices from the battery.

Areas of use:

•  Garden lighting and garden lamps
•  Battery for security cameras and recorders
•  Drip irrigation pumps and irrigation valves
•  Solar charging of caravan and camping batteries
•  Keeping boat batteries charged
•  Lighting for cabins, field huts and sheds
•  Electric fence batteries for fields and animal pens
•  Remote weather stations and measuring devices
•  Garden gate motor and barrier batteries
•  Bird repellers and wild animal repellers
   

Precautions:

•  The board is only for 12V lead acid batteries. Do not connect lithium packs (3S Li-ion / LiPo, LiFePO4): the 14.8V charge voltage is above the 12.6V full voltage of a 3 cell lithium pack.
•  Cooling is required at charge currents above 2A; without cooling the board overheats.
•  The panel open circuit voltage must not exceed 30V; do not connect a 24V system panel (open circuit voltage 36V and above).
•  Do not reverse panel or battery polarity; check with a multimeter before connecting.
•  This is a bare board; mount it in a suitable enclosure to protect it from rain, humidity and dust.

Package contents:

•  1 Piece 12V Lead Acid Battery MPPT Solar Charge Board CN3767
•  Note: Solar panel, battery and connection cables are not included in the package.