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What is this 200 mah figure?

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Old 07-18-2003, 11:39 AM
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Zpat
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Default What is this 200 mah figure?

The last time I was out flying, I attached my Ace expanded scale volt meter to my batteries and put a 200 mah load on them and it registered a voltage in the red (below 4.8 volts).
I went home and attached the flight pack to a Digi Pace charger and discharged them.
It took over an hour to discharge the batteries. What kind of load is put on the batteries in the discharge mode?
My question is, what is this 200 mah figure we use to check these batteries. Is it the results of 4 servos with tremendous loads imposed on them or what?
If someone could please explain I would be forever grateful.
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Old 07-18-2003, 01:21 PM
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Default What is this 200 mah figure?

I assume you mean 200ma, not 200 mah. A 200 ma load is just a good load to place on the batteries to assure you are testing the battery under load. It is not excessive. For a 40 sized plane is it probably about equal to the average draw in flight... maybe a bit less, maybe a bit more, depending upon a lot of factors. If a 500mah pack gets you six flights (typical for a 40 sized), each at 10 minutes, then your average draw is actually closer to 500ma (60 minutes to kill a 500mah pack is an average 500ma draw.) I know this isn't exact because higher draw rates are less efficient, but it is close. For comparison, my giants pull close to 4000ma average loads. The 200ma tester load is small by comparison.

If you suspect something is up, double check the battery (cycle it again) and check your tester against a good voltmeter. Also check for a poor connection between the tester and battery. That will give a false low reading.

Cheers.
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Old 07-18-2003, 04:01 PM
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Default What is this 200 mah figure?

Also check the connections to your ESV. Wiggle and twist the connections, connect and disconnect a few times, etc, and see if the reading changes. A little bit of contact resistance can cause a drop of several tenths of a volt.
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