[⚡【Built in 30A BMS】36V 15Ah E-bike batteries are equipped with 30A BMS protection boards which can provide multiple protections for the batteries such as over-charge over-discharge over-voltage over-current short-circuit temperature protection with higher reliability and safety! It also ensures the consistency of voltage during use and extends battery life. ⚡ 【Multi function】 Helpdrea 36v 4-PIN ebike battery is equiped with LED power indicator to remind you to charge on time. And equipped with a safety lock (2 keys) to prevent theft. In addition the USB port (5V 1A) allows you to use it with other devices anytime and anywhere such as mobile phones and Bluetooth speakers. ⚡ 【Long Life Span】Our electric bike battery is made of waterproof ABS material and Class A cells and the riding time longer than other ordinary batteries. Each lithium battery has passed QC performance testing before leaving the factory and has more than 1500 charge and discharge cycles to protect your riding. ⚡ 【Meet Multiple Needs】36V ebike lithium battery is suitable for 36v controller and most motor(0-1000W). It compatible with lots of electirc bike tricycles folding bikes city bikes and balance bikes. Please check and confirm your vehicle voltage before placing an order to choose the battery that suits you. ⚡ 【Customer Service】We will provide 1 year post-sales for this product. Within one month if the product is not suitable or damaged we can provide free return service. You will get 36V 15Ah ebike battery * 1 battery mounting plate* 1 42V 2A charger* 1 XT60 cable* 1 3 screws 2 Key.]