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NiCad or NiMH replacement for LiPo???

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NiCad or NiMH replacement for LiPo???

Old 04-27-2005, 12:10 PM
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PilotSmith
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Default NiCad or NiMH replacement for LiPo???

I'm toying with going with something other than LiPo (due to costs) if my airframe can handle the extra weight. Here is what I would like to have. I want the lightest possible NiCad or NiMH battery pack that will supply me with 24 amps continuos for 4 to 5 minutes. I need enought cells to replace my 4 cell LiPo (14.8v) pack so I'm guessing I need to use 12 cells. Your suggestions are greatly appreciated. Thanks!

On second though I think I'm asking for too much. 3 to 4 minutes would also be okay.
Old 04-27-2005, 01:28 PM
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Red Scholefield
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Default RE: NiCad or NiMH replacement for LiPo???


ORIGINAL: PilotSmith

I'm toying with going with something other than LiPo (due to costs) if my airframe can handle the extra weight. Here is what I would like to have. I want the lightest possible NiCad or NiMH battery pack that will supply me with 24 amps continuos for 4 to 5 minutes. I need enought cells to replace my 4 cell LiPo (14.8v) pack so I'm guessing I need to use 12 cells. Your suggestions are greatly appreciated. Thanks!

On second though I think I'm asking for too much. 3 to 4 minutes would also be okay.
A 12 cell 1800 mAh Ni Cd Cs pack should give you close to 4 minutes.
Old 04-27-2005, 04:33 PM
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Default RE: NiCad or NiMH replacement for LiPo???

Wow, I just looked that up and at 50 grams per cell we are at over 21oz for the batteries alone compared to under 7oz for the LiPo!!![X(] I think that would be way to heavy. Was hoping that something closer to 10oz would do the trick. Anyone have a good link that has info on the discharge rates for various types of cells?
Old 05-01-2005, 09:08 AM
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Default RE: NiCad or NiMH replacement for LiPo???

we are at over 21oz for the batteries alone compared to under 7oz for the LiPo!!!
You don't have much choice. That's the problem with NiCad and NiMH vs LiPo. You might be able to find a NiMH battery that will be do a little better but it's not going to be anywhere near as light as the LiPo. I have a GP Super Sportster EP that came with a 7 cell NiCad pack that weighs 13 oz. The TP 3 cell 2100 mAH that I have weighs 5 oz. With a NiMH I might save a few oz. over the Nicad but I'm not going to approach the 5 oz. of the LiPo.

The only thing you can do is check specs on the batteries for capacity vs weight, keeping in mind that the discharge current needs to be enough for your application.


Mike
Old 05-02-2005, 02:05 AM
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Default RE: NiCad or NiMH replacement for LiPo???

Looks like for my application (EDF jet) I'm going to have to stick to the LiPos. I was hoping that by cutting the flight time I could maybe go with a NiMH pack for not too much extra weight. Oh well, guess there is no cheap way to get around it.

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