Yep.. and the issue of buying used batteries (for rejuvenation by
desulphator) for off-grid power was where I first encountered the use of
"testing battery internal resistance", years ago.

One example I forgot to mention which may prove worthwhile for using a
battery impedance meter, would be routinely checking SLA batteries for large
UPS batteries, if the batteries are of similar capacities/models, and most
from the same manufacturer.
Fleet vehicle maintenance personnel may also find these meters helpful when
used periodically.

Specific battery specs are becoming more readily available more recently..
perhaps just to appease potential buyers, moreso than actually being
factual.

I feel the way you do about battery *packs*.. their worthiness will become
evident in real-world use. I generally put stickers on rechargeable packs
for noting dates and charging durations.
I thought that one good use for the battery impedance meter would be to help
match cells for pack building.. and maybe it would be after some rather
extensive testing experience (hundreds of cells).

Although I have several battery load testers (and hydrometers) for large LA
batteries.. load testing can be very useful, but not very scientific without
a precise timer and/or other means of plotting the battery's output during
the test (also temperature).
Overall, I'd say load testing is a reliable good/bad test (no large grey
area) when checking high capacity (automotive sized) batteries.

--
WB
..........


"Jim Wilkins" wrote in message
...
On Feb 16, 6:32 pm, "Wild_Bill" wrote:
...
It seems that the meter's usefullness would mostly be of use for comparing
readings of nearly identical cell/battery types, but otherwise just a tool
to gather readings which could be useful for statistical data (which may
or
may not be useful after many entries).
WB

It might be good if you buy second-hand batteries replaced on a
schedule. To test and accept/reject new ones you'd need the battery
manufacturer's spec sheet.

I measure a battery's remaining capacity as how long it will run this
laptop. When the screen brightness changes the inverter has just shut
down.

jsw