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Old August 25th 10, 01:41 AM posted to rec.aviation.soaring
Martin Gregorie[_5_]
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Default Glider Batteries and Chargers

On Tue, 24 Aug 2010 08:03:48 -0700, Tony wrote:

I went to the local Interstate Battery store. Picked up a 12V Sealed
Lead Acid battery, 7 amp hour I think but maybe 10. Either way plenty
of juice to run my Microair radio and Cambridge FR. I also bought a
charger from them with a float mode. Usually I plug it in before I go
to bed the night before a flight and take it off in the morning and its
charged up real good.

SLAs in good condition have a very low self-discharge rate, so IMO its
better for the battery to put it on charge as soon as you get home and
then put it back in your flight kit when the charger says its done or
next morning if red light is still on when you go to bed.

Example of holding charge: yesterday when I ran the discharge rate test
Eric asked about I used one of my flight batteries to power the charger
while it discharged my other flight battery. Pulled 22 mAh out of the
test target and (probably) less from the other one. After the test both
went back on the multi-stage SLA chargers and both were showing green
lights in under 30 minutes. Both batteries are 3 years old and were last
charged overnight 14 days ago directly after I last used them, so can
have lost very little charge since then.

Yeah, I know: its been GREAT summer weather over here!


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