SLA represents sealed lead acid. This is a safer lead-acid battery that can be found in anything from a home safety system to an electric bike battery, like a car battery for a standard lead-acid battery, SLA batteries will run out too! This note is best inspired by water, but another option is to use distilled water! Tap water is not recommended. Option 1: Make your own product using evaporation! When the water evaporates and hits the lid, it condenses and drops into the bowl. Option 2: Make your air conditioner work Option 3: make nature work for you not all air conditioners have valves like me and you may need to install something to collect your water. Place distilled water in the ideal syringe so you can carefully add water to the cells. Or you can make a mess like me. Whatever you use, be sure to enjoy them! These 24ah batteries (upgraded from 10ah) will make my e-bike faster and faster! ) Please don't forget to vote if you like!