In the event of an overcharge condition it is possible for excess pressure to build up inside your battery.
Vented lead acid batteries.
Since these are stored inside your vehicle you run the risk of inhaling dangerous battery acid vapors.
While nicd loses approximately 40 percent of their stored energy in three months lead acid self discharges the same amount in one year.
Overcharging especially if the battery is old heavily corroded or damaged can produce h 2 s.
Such treatments are rarely if ever effective.
Epsom salts reduces the internal resistance in a weak or damaged battery and may allow a small amount of extended life.
High performance batteries are designed to give long services life.
Vented lead acid batteries are commonly called flooded spillable or wet cell batteries because of their conspicuous use of liquid electrolyte figure 2.
They are maintenance free in the sense of not requiring the addition of water to offset hydrogen gas released during the charging process.
Most of the battery complies with bs 6290 din40738 and iec standard.
Deteriorated old or damaged lead acid batteries should be removed from service as damaged batteries are much more likely to be associated with production of h 2 s.
Crown cr430 6v flooded lead acid battery.
Chemical additives have been used ever since the lead acid battery became a commercial item to reduce lead sulfate build up on plates and improve battery condition when added to the electrolyte of a vented lead acid battery.
Flooded lead acid batteries release toxic hydrogen gas when charging.
Agm batteries must still be vented.
These products are suitably used by utilities marine oil gas and petrochemical.
This vent is valuable because it gives a good amount of airflow to keep the battery compartment cool and vapor free.
Even though your batteries are normally sealed they actually do have a venting system integrated into the case top.
As long as a vent is present and operating properly this should not present an issue.
The short answer is your mechanic is giving you the straight story and you do need to vent these batteries.
Agm batteries are a type of valve regulated lead acid battery.
Vented lead acid battery.
Vented lead acid batteriesare commonly called flooded or wet cell batteries be cause of their conspicuous use of liquid electrolyte.
They need to be enclosed and vented to the outside to prevent this gas from being trapped and creating a hazardous environment.
As the name implies this type of battery vents hydrogen continuously during normal float operation.
Lead acid has a moderate life span but it is not subject to memory as nickel based systems are and the charge retention is best among rechargeable batteries.