While it's perfectly fine to string together a few batteries to increase your storage capacity, make an effort to keep the number of batteries in your bank as low as possible. The general guideline is to make sure you have enough storage for five days' worth of power. While it may be tempting to add capacity beyond that,. The batteries in your bank need to be rotated within the circuit on a regular basis in order to provide the maximum effective lifespan. Because of the possibility of uneven charging,. Most of the deep cycles batteries that are used for solar storage require water in their cells to keep them in optimal working order. While some tout. Another common mistake made with solar batteries that can cut their lifespan short is allowing them to become completely discharged and failing to recharge them for long periods of time. When batteries reach a nearly full charge, they can begin a phenomenon known as gassing or boiling. While that may sound disconcerting, gassing is a normal part of the battery usage and is actually good for a battery. It should occur.