Ebike Battery Replacement for F2

Want a spare battery, or need NAKTO battery replacement? NAKTO Ebike Battery for F2 FEATURES 48V16A Charging: 4hours Waterproof design Energy Conservation and Environment Protection 1-year warranty   What could I do if I lost the battery key? ATTENTION: Please take care of your battery key, we don't have copy keys for sold battery  When you charger the battery, you need connect the battery and charger first.Then the the charger plug to connect with Wall. It would damage the battery fuse. How to take the battery out of the bike? 1. Take the seat down,there is a small blue bar under the seat, pull that bar up to take turn the seat straight. 2. Left hand turn the battery key to unlock (in the photo),at the same time, push the key in.Meanwhile the right hand take the battery out. What is the problem if the charger signal is always green when chargering?Is that the battery has a problem? If the single light is always green after charging at once that is the fuse of the battery burnt. If it fuse the blown, replacing the new fuse is suggested.