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Feb 11, 2003, 07:27 PM
LSF186
neonbutterfly's Avatar
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Does cold weather affect the performance of NiMH Batteries?


All kinds of newbie questions here.

Does cold affect the performance of Nimh batteries. Like, should I fly my electro sailplane when the temp is around 20 to 30 degrees?

Bob
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Feb 11, 2003, 08:29 PM
Motor Maniac
Cold affects all batteries since they work through a chemical reaction and that reaction is slowed down by extreme cold. Discharging batteries at the rate electric RC motors do does provide some self-heating, so I don't think it is a big deal at the temps you are talking about. It certainly can and is done by others, with some degradation in capacity. I can't comment personally because it never gets that cold here in SoCal, and even if it did all of us wimps out here would be huddled inside.
Feb 11, 2003, 08:58 PM

Cold affects nimh batteries more so


than Nicads. If you're using smaller cells, say 250mah nimh, power will seem non-existent unless you take the pack right out of the peak charger and into the plane. I almost use nicads exclusively when it's colder. However, the new Hecells seems to be doing as well as my 600AE and 500AR nicads. This maybe be partly because I keep them in a very small cooler which retains the heat and keeps them warm prior to flight.
Feb 11, 2003, 11:28 PM
Registered User

Ni-MH vs temp


Here is the panasonic small Ni-MH characteristic.
The temp does not so concern with the end of flight capacity.
But, Ni-MH can not draw high current at low temp. I could not find that kind of graph, except description in data sheet.
Feb 12, 2003, 04:09 AM
I "plant" trees (balsa)
Gary Retterbush's Avatar
Ni-MH's do not like the cold anymore than Snowbirds do!

I ran some primative tests and found they can not deliver current when they are well below freezing. The trick is to charge them at 1C which will get them warm and then use them right away plus to use them enough in flight to keep the temp up a little.

I have been test flying this winter with Ni-MH's at temps down to 12F using this method and it works pretty well. I would NOT use Ni-MH in cold weather if they are strictly for the receiver. Also don't get care away with a nice winter thermal and forget to turn the motor on every once-in-awhile!


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