The newer type sealed lead-acid that uses absorbed glass mats between the plates. It is sealed, maintenance-free and the plates are rigidly mounted to withstand extensive shock and vibration. Nearly all batteries are recombinant, meaning they can recombine 99% of the oxygen and hydrogen. There is almost no water is loss.
The charging voltages are the same as for other lead-acid batteries. Even under severe overcharge conditions, hydrogen emission is below the 4% specified for aircraft and enclosed spaces. The low self-discharge of 1-3% per month allows long storage before recharging. The costs twice that of the flooded version of the same capacity.
Inexpensive and simple to manufacture.
Mature, reliable and well-understood technology – when used correctly, lead-acid is durable and provides dependable service.
The self-discharge is among the lowest of rechargeable battery systems.Capable of high discharge rates.