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Old Aug 12, 2003, 10:54 AM
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Can I build a battery pack from these cells?

I have a some cells here that I took out of a busted laptop battery pack, the pack had been in a laptop that was damaged and the pack shell was unusable so my brain went to work thinking about salvageable RC stuff. The laptop battery pack was labeled "NiMH Li-ION" I got a total of 8 cells out of it. Each cell is covered in a light green wrap. The only marking on the individual cells is "0303N", each cell is almost an inch longer than a typical AA cell. My question is, how do I wire these cells up for a rc airplane pack? Is it possible? I have a NiCD/NiMH charger at the house and a Slow Stick plane, could these be made into packs suitable for Slow Stick use? Anyone got a web page that shows you how to build packs? I have no idea what the mah rating of these cells would be nor do I know the voltage.


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Old Aug 12, 2003, 11:01 AM
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==battery pack was labeled "NiMH Li-ION" ==

That seems odd, NiMH and Li-on cells are two different types of cells. I would think they're NiMH because of the number of cells though. I'd be hesitant to make a flight pack out of those unless you know exactly what they are, you can't charge li-on cells on a NiMH charger and could even blow them up if you tried!

Moving over to Batteries and Chargers...
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Old Aug 12, 2003, 11:54 AM
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I think they are NiMh cells too. It seems you have a thermal fuse there which is normal for these, a LiIon cell normaly has some electronis instead. If you check the cells on a meter you can find out, over 1.4v and you have LiIon unless they are flatter than flat !

Terry
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Old Aug 12, 2003, 01:38 PM
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They measure 1.2v on a fluke voltmeter, could I wire them in a set to get to 6volts?
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Old Aug 12, 2003, 03:02 PM
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Ok, they're definitely NiMH cells, 1.2V each, I think if I wire 4 together it might make a nice little flight pack. I'm going to try it and see how it works.....carefully.
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Old Aug 13, 2003, 09:12 PM
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Update: I built a small pack out of 4 of these cells. Total voltage measured about 5v. I charged it on my Intellipeak Pulse charger at the 1.0 setting and then tried it on my slow stick. It worked, sort of. It would power the servos just fine but would only push the prop speed to what I would think is about 1/2 throttle when I'm using my regular 600mah 7.2v NiCD GWS pack. If I wire 6 of them together to get near 7.2v would it up my throttle ability?

I'm using a standard GWS Naro flight pack.


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Derek
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Old Aug 14, 2003, 09:03 AM
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Phoenix,Arizona, United States
Joined Jun 2002
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your regular 7.2 volt nicad pack is 6 cells, so yes you can make a 6 cell pack out of your new cells, you could even make a 7 cell and it wouldnt hurt much, just make sure the cells are close to the same voltage when you make your pack, and slow charge them to even out the voltages.

Dylan
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Old Aug 14, 2003, 09:06 AM
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I made a 5 cell hump pack out of the cells, weird thing is, it would power the servos but not the engine. Any ideas why? Total voltage was about 6.2v
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Old Aug 14, 2003, 09:56 AM
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A 5 cell pack is probably not enough for the low voltage cutoff of your ESC
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