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Old Nov 05, 2002, 09:05 PM
I am to the limit!
Jeff Costantino's Avatar
Coral Springs, FL
Joined Sep 2002
138 Posts
NiMH AA cell problems

I just bought some Energizer NiMH cells for a non-RC project (rebuilding the battery pack in my handheld) and I have a couple questions:

Aren't NiMh cells supposd to come partially charged and not empty? These came with 0.1v in each! Also, I figured I'd set them up to charge in my 12v cigarette plug charger (Electrifly) it's supposd to charge 6-8 cell packs and I suppose the status LED isn't lit because this is only a 2 cell pack - is it even charging? I can hear the transistor switching on and off in the unit. I have this on the lowest (200mAh) is this OK? I believe these cells are 1600 mAh.

They're probably duds and I can't return them because I solidered on them I'll try to wipe off as much as I can but I'm sure I'll have a time getting my $8 back...

Jeff
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Old Nov 05, 2002, 10:03 PM
Registered User
Kings Park, New York, USA
Joined Sep 2001
813 Posts
Hey Jeff Costantino

Hey Jeff Costantino

I don't know what an Electrifly charger is.

for starters, you need to slow charge the pack with 160mA charge for 15 or so hours. Then after that, either charge for C/10 for 15 hours, or get a good peak charger that is made for NiMhs. I would probably charge between 800mAs and 1600mAs. depending on charger and batteries. If the batteries do not peak they will start to get real warm and you will kill them.

I have never seen a .1V cell, try the slow charge, they may come back.

1 thing to keep in mind, is NiMhs are poor in the cold. i use Sanyo 1100ma NiCads in my transmittor for this reason instead of niMhs.

in my cheap HiTec focus 3 AM Transmittors, I have been using Hosfelt cheap AA NiMhs, think 1100 on some and 1300 on others. They have been working fine for the past few years. they do tend to give up the ghost in the cold without much warning far quicker than in the summer. I just peak with receiver pack.

ron Parigoris
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Old Nov 05, 2002, 10:11 PM
I am to the limit!
Jeff Costantino's Avatar
Coral Springs, FL
Joined Sep 2002
138 Posts
The Electrifly charger is made by Great Planes.. it will peak charge NiCd and NiMH packs but it only does 6 to 8 cells correctly.. I had this two cell pack on that charger for about 45 minutes and the pack charged to 2.4v. I put it in the device (a WinCE handheld) and hope the charging base can deal with these cells... I shouldn't have to do this in my opinion though. These cells shouldn't be completely discharged. I wish I hadn't solidered these cells before finding out they are screwed up.

Jeff
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Old Nov 05, 2002, 11:02 PM
I am to the limit!
Jeff Costantino's Avatar
Coral Springs, FL
Joined Sep 2002
138 Posts
I fixed it.. the pack has a resistor (which I thought was a thermistor) and a "jumper" to ground that tells the charger there are rechargable cells involved. Add the missing circuitry and voila! everything seems to be working as expected.

Jeff
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