Battery health tesing

I have had been very happy with the CBAII computerized battery analyzer
from Westmountainradio.com. Click the RC Model Products button on the
left of the page.

It runs abou $100 and hooks to a PC to plot discharge curves.

They also offer the whatthour meter which provides load information.

More expensive solutions than some others suggested here, but very
convenient and easy to use.

wrote:

I'm wondering if there's a simple or straightforward way to test an SLA
battery for general condition. Or a device I can buy that sucks a
charge out of a battery over a few hours and reports its actual
amp-hour capacity?

I've built Peter Nyffelers amperehour tester:

http://www.ppc.ethz.ch/~peny/sf/ah_test.html

The simple circuit is easy to build out of standard components.

It discharges the batteries with a fixed constant current until the voltage
is down to 10.5 V then it switches the battery back to the charger.

With a discharge current of 1 A the timer shows the capacity in ampere
hours.(at 1/2 A multiply by two).

This tester is convenient when you take care of a lot of batteries:
- Charge battery (I do this with a second charger)
- Connect the battery
- Reset the hour meter
- press the discharge button
- The next day the battery is fully charged and the hour meter shows you its
capacity.

Sometimes it is possible to revive tired batteries with a few cycles of
discharge and recarge (use a smart 3 phase charger).
If 5 cycles don't help you can give up.

George

Georg, what is the "M1 Elapsed Time Meter"? This looks like a simple
enough project but I'm not sure I can identify enough of those
components (ask me about software!). I do know how to handle a
soldering iron though...