Background
I have an electrical scooter with 6 x 12Volt lead acid batteries (72 Volts total), which are now in such a condition that they can barely get me to my work and back. I got a bunch of used UPS batteries from a friend, and want to check their capacity and compare them with the batteries that are currently in my scooter.
I roughly think I know how to measure their capacity, after loading them I should discharge them at a certain rate and see how long it takes before the voltage drops below a certain threshold. I'm not sure about the exact numbers though, and I'm also not quite sure how I should discharge them at the same rate as my scooter would typically do (power a heater or something like that?).
Question
Is there a device/machine/instrument that can do all of that for me? Load the battery, discharge it at a constant rate and log the results.
If not, I guess a UPS hooked up to a computer could be programmed to do the job? Any ideas?
Best Answer
Yes, there are lead acid battery testers that will tell you the condition of each battery. They are often used by UPS service technicians during preventative maintenance checks to check on the health of each battery in a large series string.
Here are a couple examples:
http://www.cadex.com/technology/our-technologies/spectro http://www.bkprecision.com/products/electrical-battery-testers/battery-capacity-analyzers/600-12v-sla-battery-capacity-analyzer.html
The good ones probably cost more than a set of replacement batteries for your device, but if you can find a UPS dealer or service tech, they may be able to test your batteries for a small fee.