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fdr
10-29-2005, 03:17 PM
I've got a large airplane powered with a 24 cell NiMH pack of GP3300s. With winter approaching, what is the current wisdom in storing the pack for several months - fully charged, half-charged, or discharged?

GeraldRosebery
10-29-2005, 07:10 PM
I've got a large airplane powered with a 24 cell NiMH pack of GP3300s. With winter approaching, what is the current wisdom in storing the pack for several months - fully charged, half-charged, or discharged?

Unlike NiCd's store NiMH fully charged. Remember that they self discharge and you should top them off every three months or so. That means once during the winter.

hoppy
10-29-2005, 09:06 PM
Here's some storage "jibberish" from PowerStream on recommendations for battery storage. :)
http://www.powerstream.com/Storage.htm

See paragraph 6 in this document - http://www2.panasonic.com/webapp/wcs/stores/servlet/vFAQ?page=NimhBatteriesFAQ&storeId=15001

Then read 4th paragraph here - http://www.hardingenergy.com/faq.htm

Confused?????

Than look at page 8 of http://www.sanyo.com/batteries/pdfs/twicellT_E.pdf

The one thing they agree on is to store at a low temperature.

Warden
10-30-2005, 12:31 AM
Conflicting suggestions notwithstanding, I've had excellent results storing Nicads discharged and Nimh's fully charged.

turnwaldw
10-30-2005, 05:36 PM
As a long time RC racer I always stored my nicads fully discharded and nimhs like the rest fully charged. I have installed what they call a bullfrog on my nicads that keeps them discharged and have never had a problem with them yet just my 2 cents
Dave

Dereck
11-08-2005, 06:55 PM
I've got a large airplane powered with a 24 cell NiMH pack of GP3300s. With winter approaching, what is the current wisdom in storing the pack for several months - fully charged, half-charged, or discharged?

I usually store mine in the same toolbox I haul them to the flying field in!

Seriously, fully charged seems to work - the real important thing is that they'll be sluggish the first couple of flights after a long lay-off. For those flights after even just a month or two without flying (which is happening to me a distressing number of times of late), performance will be markedly sluggish. So don't go blasting off the strip next Spring or whenever thinking you'll have the performance you had last time out.

After a lay-off, I usually top my packs up on a slow-ish 1C charge, no technical reason, it just feels right, fly around somewhat mellow and don't run them right to where she won't fly, then fast re-charge after cooling and then it's usually business as usual.

Hope that helps

Regards

Dereck

Jason T
11-09-2005, 05:57 PM
Everyone I know using sub-C Nimh cells with store them at half charge. Now, over the winter is a longer time frame. Maybe do a discharge and half charge cycle once during the winter.

ragbag
11-12-2005, 09:37 PM
I'm surprised Red hasn't jumped in on this one. He always recommended storing batteries in the refrigerator.

Go to his site and read up, not sure if this is there or not, been a long time since I looked myself.:D
In fact, I just bought a smaller frig at a yard sale and have a 3 cubic foot one for sale, price is right, the shipping would be terrible!!!!

By George

http://www.rcbatteryclinic.com/

ForestCam
11-12-2005, 10:14 PM
I'm surprised Red hasn't jumped in on this one. He always recommended storing batteries in the refrigerator.

Go to his site and read up, not sure if this is there or not, been a long time since I looked myself.:D
In fact, I just bought a smaller frig at a yard sale and have a 3 cubic foot one for sale, price is right, the shipping would be terrible!!!!

By George

http://www.rcbatteryclinic.com/
You'd be suprised, I shipped a 28 lb. amp from MI to WV for $11 with FedEx Ground.