On 10/12/14, 7:38 AM, Stormin Mormon wrote:
On 10/11/2014 11:04 PM, J Burns wrote:
On 10/11/14, 9:25 PM, Stormin Mormon wrote:
On 10/11/2014 8:39 PM, J Burns wrote:
I test the amps of alkaline batteries because a perfectly good battery
may have much less than the nominal open-cell voltage.


Do you load test, or just drop a dead short?

Dead short.

What amp ranges have you seen?

Q: What do basketball players wear when they die?
A: Dead shorts.

A new AA might show 5 amps or more. 3 amps may work in many devices. 1
amp is low. Internal resistance increases as an alkaline battery is
used up. Assuming an open circuit voltage of 1.5 V,

5 amps would mean about 3/10 ohms of internal resistance.
3 amps would mean 5/10 ohm.
1 amp would mean 1.5 ohm.

Energizer says a brief short is harmless. If I'm checking an assortment
of AA's, surge current is a quick way to tell which ones to discard.
Open-circuit voltage doesn't seem to work as well.

I also use current to check 9 V batteries, but I don't do it enough to
remember what a new one should produce. I just check a suspect battery
against a new one.