maintenance free electric Bike battery 1,It is designed specially for electric vehicles, such as electric bicycle,electric golf cart,electric wheelchair, mower, dust collector etc.2,It has safety, low resistance so recharge is easy and energy output is moreremarkable. It will last a long time both physically and chemically and deep dischargerecovery performance.3,It is valve regulated which makes it impossible to spill, and with its tightly sealedconstruction, it can be operated from any angle!4,The container material is frame retardant ABS with Fire Certificate and batteries arestrictly tested by our computer charge/discharge system.We are an established full line battery company so please feel safe doing businesswith us. Thanks for browsing our product and good luck.