On 12/07/2019 13:42, Harry Bloomfield wrote:
laid this down on his screen :
Measure oc battery voltage

Easy.
Measure battery resistance

How do they do that - place a small load on the battery, then measure
the voltage drop? Cannot be much of a load, in such a small device.

It could be a failt large load, but only for a very short time.

SteveW