Which Battery

[damienengland]

Batteries have two conditions that affect their performance and lifespan. State of charge (SOC) and State of health (SOH). State of charge is the electrical pressure stored in each cell from charging (Volts) but more importantly is the state of health, which is the batteries ability to deliver current under load (internal resistance).

SOH deteriorates when sulphation of the cells occurs and this starts to happen when a 12VDC battery voltage drops below 12.4VDC A lead acid battery is fully charged at 12.72VDC, at risk of sulphation at 12.4VDC and chemically empty at 11.7VDC

High sulphation results in a high internal resistance across the cells and can lead to boiling off of the acid when charging. This boiling off can show itself as an explosion, warped or cracked battery or acid leakage from battery vents or cell caps.

This might be what you are experiencing if the battery has been left standing for a long period without charging.

Batteries that have fallen below 5VDC may not be recoverable and if they do recover under charge, will most definitely have cell sulphation which limits their CCA ability

Hope this is of some help

[thatotherguy]

We have a battery in our ski boat that is 11 years old and one used to move cars around that is 10 years old but they are always disconnected after use,not sure if disconnecting the has anything to do with their long life.