
Originally Posted by
oj88
The battery warning indicator lights up when the battery is not charging. Meaning, it only lights up if there is something wrong with the charging system.
There's hardly any practical need for a battery voltmeter as it doesn't show any indication of battery condition or health. People install them (including myself) for their novelty.
To avoid being stuck with a dead battery, you should have its condition tested every time the vehicle undergoes preventive maintenance (typically every 4-6 months). A proper test would indicate if the battery is nearing the end of its service life. Typically, when the state of health (SOH) goes down to around 50-60%, it's time to consider retiring it..... or suffer inconvenience or bitter humiliation down the road.