Battery test

The battery acid density can be used to measure the state of charge. However this check produces uncertainty caused by a design-related range of variation. The acid density e.g. for a charged battery is 1.28 kg/l (in the variant for hot countries the acid density is 1.23 kg/l).

Another interference factor is the acid layer immediately after filling with distilled water.

Battery wear with partially sulfated and/or heavily contaminated panels will also lead to incorrect acid density test results.