Purchase notes 1 before purchasing, please confirm whether the picture and battery back port are correct. If you are not sure whether the battery is compatible, please click here to contact customer service for purchase guidance. Don't buy wrong wrong purchase and cannot be used 2 the port on the back of the battery is different, so it is not compatible and the battery base cannot be replaced. 2 Pins sse-221 : there are 2 pins on the insert port on the back of the battery. Suitable for two-pin battery bases. 4 Pins dp-5c : there are 4 pins on the insert port on the back of the battery and no white screws next to it. 4 Pins hl085 : there are 4 pins on the insert port on the back of the battery and 2 white screws next to it. 3 Free shipping on all orders.This bike battery are shipped from united states & china warehouse, delivery time is 7-25 working days. 4 Batteries are special items and cannot be returned. No refunds or exchanges if you buy the wrong battery applicable bike model style bike model bike style bikes 48v 18ah 2 pins sse-221 f26ful amak00021 seat tube without controller box 500w 48v 48v 12.8Ah 4 pins dp-5c f26ful amak00021 seat tube without controller box 500w 48v 48v 13ah 4 pins hl085 f26f spa000061 seat tube with controller box 500w 48v product details battery type e-bike lithium battery pack applicable scope f26f battery cell composition lithium color black rated voltage 48v rated capacity 12.8Ah 13ah 18ah battery power 614.4Wh 624wh 864wh max charge volta...