In order to prolong solar battery bank life span, here are some things you can do:
Rotate batteries periodically will help ones in the middle of the system to balance the charge.
Leave The Battery Charged
Never leave a battery left uncharged for too long because it can damage it.
Learn how to charge a 12V solar battery bank with a 24V solar panel here
Limit The Number Of Batteries
More batteries mean more connections, and each connection increases resistance and can cause uneven charging. Limit the battery to 16 or less, so a higher capacity battery is the go-to option instead of a bunch of smaller capacity ones.
Reduce Cable Resistence
Use larger cables to reduce resistance and allows for more even charge. Please use 4/0 size cable for 12V and 24V systems, and 2/0 for 48V systems.
Use Distilled Water
Do not add battery additives or electrolytes because they can harm the battery
Gassing is normal for a battery. In fact, it should on a regular basis at around 14.1 Vdc, 28.2 Vdc, or 56.4 Vdc.
The process will produce hydrogen and water build-up, so having ventilation is important.
Equalization controls the overcharge of the battery and prevents some cells from reaching a full charge on a regular basis.
It’s because individual cells within the battery can be unevenly charged overtime during normal cycling. Equalization also knocks off sulfation off the plates through gassing and returns all the cells to full charge.