Battery monitoring. How ?

[Paul1]

T 6.1. Lot of threads of battery levels which state for example, starter battery 75% leisure batteries 60%. How so precise? Multimeter use ? I know a check is made by looking at the gauge on screen above mirror but I assume it isn’t that precise and is it just for the camping batts. Handbook doesn’t help. Checked car menu, am I missing something on screen?

 

[m10chkcalifornia]

Its not particularly sophisticated. There is a relationship between charge and voltage and you can find graphs for different kinds of batteries on the web. The assumption is that the battery has no load which is hard to achieve in modern vehicles (due to lots of systems staying live even with ignition off). But basically a multimeter and a graph are your starting point.