What is the difference between an open and sealed battery?
Batteries can be either open or sealed. Most industrial batteries are sealed. You can easily recognise open batteries as they contain tops that can be opened. This means that the battery may need to have its fluid levels regulated. In addition to open batteries needing occasional refilling with water, they are also freely ventilated. This means that they have valves where the storage gasses can escape. Sealed batteries have a special recombination structure that ensures all the gasses are converted to water, meaning that both the gasses and fluid levels are kept in equilibrium. This means that sealed batteries are maintenance-free. AGM and gel batteries look different, but are always seal valve regulated (VRLA) batteries.
