Some battery manufacturers recommend equalising their batteries a couple of times a year. You can do this with a dedicated device, or a function on your charger if it has one.
Equalising means charging them fully, then charging it again at a 10% higher voltage than normal. What this does is removes the sulfation that is a normal part of battery use and helps the battery achieve a longer working life at a greater efficiency.
Remember your battery will vent much more during this process so good ventilation is necessary due to the risk of explosion. Also it should only be done in cooler temperatures.
It’s recommended that once fully charged you check with an SG (Specific gravity) meter if your battery is OLA (Open Lead Acid) and only equalise if the SG difference between the cells is 0.030.
You also have to check the SG of the battery during the equalisation process, if you don’t you could damage it when it no longer requires the higher charge. The voltage also should be about 10% of the charging voltage. So if you normally boost at 14.4 the equalising charge should be +10%, ie: 15.8 volts.
DON’T leave anything connected to the batteries while equalising and only do it in a very cool environment.
Check with the manufacturer for dedicated advice.