This stage of charging will continue until the battery is removed. The maintenance current is needed to make up for self-discharge, which occurs to some extent in all battery types. The next thing we do with our battery is discharge it. This part is easy, we just use our total station, GPS receiver, data collector, radio, or other piece of portable electronic equipment. But what happens when the battery doesn't perform like it was supposed to.
Rechargeable batteries are famous for having problems.
They get overcharged, undercharged, develop sulfation, develop shorted or open cells, the list goes on. Let's address these problems and explore some solutions. Overcharging batteries shortens their service life. When a lead-acid battery is completely charged, continued charging causes the electrolyte to break down and form hydrogen and oxygen gases. If the pressure becomes great enough, the sealed one way valves on the battery will open and vent the excess gas pressure and possibly liquid electrolyte.