I guess a 12v automotive light bulb would be a readily available load?
Perhaps one of the electronic wizards here could suggest an
appropriate wattage for a meaningful, safe, fast test?

Also, is it valid to do a 'fast' test when a glider load is hopefully
closer to 10 to 20 hrs? Can we presume that if the battery can cope
with a 'fast' discharge then it should be able to handle a slow
discharge rate?

Cheers,

Jim Kelly.


"Dusty" wrote in message
.com...
| Assuming your amp demand for your sailplane averages about 1 amp,
buy a 10
| to 15 ohm, 20 watt resistor. Safely hook up the resistor across the
battery
| (it will get hot), and measure periodically. When the voltage starts
| dropping fast (11 volts?), disconnect the resistor. Plot the voltage
versus
| time.
|
|
| "Kurt" wrote in message
| om...
| It seems that most ships are using a 12 volt 7 amp battery for
ships
| power, radios, varios computers etc.. Is there a way to test the
| battery to see when it should be replaced with a new one? I don't
| know how old my ships battery is and I was hoping that someone had
a
| "simple" way to test the battery at home (load test vs. time vs.
| voltage?).
|
| Thanks
|
| Kurt
|
|
|