"COLIN LAMB" wrote in message
ink.net...
In fact, you can often hang a auto lamp across the battery with a digital
voltmeter and watch the voltage drop. The less drop, the better the battery.

That is exactly how I have been doing it for years, and I have never found
a need for anything more fancy. For small gel cells, (as are used in gliders) I
use a digital voltmeter and a 50-watt sealed beam light. For larger batteries,
I use a commercial load tester that you can buy at NAPA or any similar auto
parts store for about $50.00 US.

Vaughn