Built-in 20A BMS】Deep cycle battery has internal with 20A BMS, which can prevent battery overcharge, current short circuit, with high temperature auto disconnect function, better protect the battery.It can prevent charging over 167°F (75°C). 【Advanced technology】LiFePO4 battery manufacturing is completed by four automotive grade 3.2v20ah batteries with high energy density, stable performance and more power. High quality cycle performance, fast charge and discharge speed continuous output 20A, charging efficiency up to 100%, no matter what state the battery is in, as long as the charge can be used. Support battery expansion, up to 4 in series (12V 20AH). 【High Quality Life and Weight】12V 20AH Lithium Iron Phosphate LiFePO4 battery has long life and light weight. 12V 20AH LiFePO4 battery provides more than 5000 cycles, lead-acid batteries only 400 to 500 times, the life of LiFePO4 battery is 10 times longer than standard lead-acid batteries, and the weight of LiFePO4 battery is 50% lighter than lead-acid batteries of the same capacity, so it can be more convenient to Carry 【Safety & Environmental Protection】 Lithium iron phosphate chemical structure makes lithium iron phosphate batteries will not burn or explode even under high temperature, impact, crash and puncture. It has the highest level of safety based on the CE/ROHS test certificate of the battery inside the cell. And it does not contain any heavy metals and rare metals, more environmentally friendly, known as the green energy battery.