BT100 battery is used with solar panels. Ideal for yachts, campers, RVs, camping, outdoor lighting systems, solar and off-grid, making your travels as easy as plugging in at home. Additional Details ------------------------------ Bullet point: 【Large Capacity】BT100 batteries can be connected in parallel and series to obtain larger capacity and higher voltage. Maximum series connection: up to 4 identical cells, up to 48V. Parallel connection: up to 4 identical batteries with capacities up to 400Ah. The series-parallel connection makes it ideal for drone charging stations, electric golf carts, and home backup power.