In article ,
William Sommerwerck wrote:
I have an electronic battery tester -- an expensive device.
This gives a instantaneous readout of the capacity in Ah.
If you don't know what it should be it is fairly useless.

You cannot take an "instantaneous" reading of a cell's Ah capacity. Such
a measurement requires actually draining the battery.

I dunno how it actually achieves this, but in practice it's what it does.
And is pretty accurate if you check it against doing an actual discharge.
Nor does it need the battery to be fully charged to test it.

I've used it on many batteries of different capacities - and on known
good ones gives a readout within something like 5% of the stated capacity.
Unless the charge is too low for it to work.

For me, it's invaluable.

--
*Puritanism: The haunting fear that someone, somewhere may be happy.

Dave Plowman London SW
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