A built in valve will release excess gas in case of a severe overcharge.
Vented type lead acid batteries.
These batteries have a negative and a positive terminal on their top or sides along with vent caps on their top.
The difference between the two is the construction.
Undercharging results in sulfation of the plates.
They can be topped up when required and are therefore more tolerant to high temperature operation and over charging.
A vented battery can give off sixty times more gas than a vrla battery in normal use.
Crown cr430 6v flooded lead acid battery.
The glass mat in the battery absorbs the hydrogen produced prior to it escaping to the atmosphere allowing it to remain inside the battery.
Generally overcharging will boil out the water resulting in cooked batteries that smell very bad.
Vented lead acid vla group batteries are all open allowing gas to escape without any positive pressure building up in the cells.
About 60 of the weight of an automotive type lead acid battery rated around 60 a h is lead or internal parts made of lead.
For example there are approximately 8 7 kg 19 lb of lead in a typical 14 5 kg 32 lb battery.
Valve regulated lead acid vrla batteries are the most widely used battery type because of their high power density and ease of use.
Vrla batteries are considered to be sealed because they normally do not allow for the addition or loss of liquid.
They are maintenance free in the sense of not requiring the addition of water to offset hydrogen gas released during the charging process.
An agm battery is constructed by compressing a glass fiber mat between each plate.
Flooded gel agm battery bulging is caused by undercharging.
Vented lead acid batteries are commonly called flooded spillable or wet cell batteries because of their conspicuous use of liquid electrolyte figure 2.
The free electrolyte also facilitates cooling of the battery.
There are two types for vented or flooded lead acid batteries namely tubular and plante.
Regulated lead acid vrla batteries.
Agm batteries are a type of valve regulated lead acid battery.
These products are suitably used by utilities marine oil gas and petrochemical.
The plante battery is both mechanically and electrically more durable.
Vented lead acid battery high performance batteries are designed to give long services life.
These batteries are designed so that hydrogen and oxygen are recombined within the battery rather than being vented.
Most of the battery complies with bs 6290 din40738 and iec standard.
For tubular battery normal life is 8 10 years.
The balance is electrolyte separators and the case.
