How do I load test a VRLA battery

[Drunkard #1]

A while back, I upgraded all my UPSs batteries because the old ones were melting. I now have 112 batteries in various conditions, plus a few more gathered over the years.

I've bought a charger, and plan to test them one by one. How do I do this? I took a piece of stainless wire and make a DIY resistor, which gives 5 amps at 11.5 volts. The battery doesn't heat up, and returns to 12.5 volts when the load is removed.

Is this the right resistance (approx 2.5Ω)? What voltage should I expect during the test and after? How important is the timing of the load test?

I've read that the current should be 3 x the Ah rating (so 15A in my case), the voltage should be checked 15 seconds into the test, and the voltage shouldn't drop below 10.5V. How does this sound?

Thanks.

 

[sajunky]

Generally OK, but I recommend full cycle individual discharging/charging (at normal rate 0.1C - no stressing) before testing. A reason is that batteries are not uniformly charged (when connected in series with a bad battery in a string), giving full charge for a weak battery and not charging fully a good ones. Also leave alone for few days before testing, to add effect of self discharging.