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Shouldn't these numbers be closer to equal?

Old 05-20-2011, 05:40 AM
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Default Shouldn't these numbers be closer to equal?

To estimate flight time I was reading a post that said. Determine 80% of pack mah. Run pack down to that level keeping the time. Do that a couple of times and you should know real close where to set your timer. [I know you wont be wot all time]. Ran 1000 pack down right at 800 used on tenergy 2 meter. When I charge back up to full the accucel 6 only puts in 630. What gives? Are those mah or just random numbers the mfg. have of keeping up with volume?
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Old 05-20-2011, 06:47 AM
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I cant explain the difference other than inaccuracy of one or both measuring devices. In reality, due to the fact that batteries are not 100% efficient you will always put a little more energy in than you get out. you certainly wont get more out than you put in, that would be impossible.

Anyway... as a way of estimating flight time it's fundamentally flawed because you dont know how much throttle to use in order to simulate a typical flight. running the battery down at WOT is likely to give far shorter run time than you would actually experience in flight. Also you can never be sure if the battery will actually deliver it's full rated capacity.

A better way if you are confident to glide, or land under much reduced power, is to simply fly to the low volt cut off and then use 80% of that flight time.
Alternatively check the resting voltage after flying and compare that to the figure you got when you bench tested the battery.


Last edited by JetPlaneFlyer; 05-20-2011 at 01:47 PM.
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Old 05-20-2011, 09:54 AM
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Things like the Tenergy 2 meter which claim to show you amount remaining in a pack are never really accurate. In effect they are just measuring the pack voltage and from that making a guess (or estimate if you want it to sound more technical ) at how much capacity remains.

The amount of charge put in by the Accucell is likely to be a lot nearer the truth.

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Old 05-20-2011, 05:05 PM
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The 'Steves' have given you good advice

The better/safer way to determine your max flight time is to start out with a somewhat short flight but fly the way you normally do - dont baby the plane and dont push it extra hard. Just a normal flight.

Recharge the battery and note how many mahr was put back in. Gradually make your flights longer - keeping track of how much you put back in - until you are puttinmg back in about 80% of the battery capacity.
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