HOW TO CHOOSE A BATTERY 

The GP-PWM-30-UL is suitable for use with lead acid batteries (vented, GEL, or AGM type) as well as some lithium iron phosphate (LiFePO4) batteries that are supplied with a Battery Management System (BMS). If using lithium ion, it must be lithium iron phosphate (LiFePO4) chemistry with a BMS. No other chemistries are compatible.

Lithium batteries typically have maximum allowed charge currents. These maximums typically decrease in cold temperatures. GP-PWM-30-UL does not limit current for these restrictions, and system design of the solar array must account for this.

Be sure to follow all battery manufacturer safety instructions.