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Ni-Mh pack drops below 5 volts

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Ni-Mh pack drops below 5 volts

Old 07-06-2005, 03:17 PM
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aidan_jos_mills
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Default Ni-Mh pack drops below 5 volts

Hi

I've got a Thunder Tiger EP Super cub. The box recommends a 7 cell 600 Mah Ni-Mh battery. I bought a 7 cell 730 Mah Ni-Mh battery. But between half and fu;ll throttle the esc cuts the power because the pack drops below 5 volts is this normal. The setup is a 370 motor with a 2,67:1 gear ratio swinging a 8x6 APC electric prop. Can anyone offer advice other than buy a lipo[8D] witch i am consedering when i get money.

Thanks
Old 07-06-2005, 03:20 PM
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exeter_acres
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Default RE: Ni-Mh pack drops below 5 volts

what kind of battery did you buy?

is it taking a full charge..?

while it may be a higher mAh it may not have as high of a discharge rating
Old 07-06-2005, 03:26 PM
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aidan_jos_mills
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Default RE: Ni-Mh pack drops below 5 volts

Hi

It is a GWS battery no C rating, but thay are AAA cells, the box also said AAA cells.

Aidan
Old 07-07-2005, 10:06 PM
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Matt Kirsch
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Default RE: Ni-Mh pack drops below 5 volts

You could very well end up in the same situation with a LiPoly pack.

Every cell has its limits as to how many Amps can be drawn before it gives out under the pressure. In this case, you're drawing more Amps from the AAA pack than it can handle. This means you need physically larger cells if you want to stick with NiMH.

AAA cells are generally limited to around 6 Amps before their voltage starts to drop drastically under load. A typical "370" a.k.a. "Speed 300" or "EPS350C" application will run between 8 and 10 Amps.

The ideal cells for a 370 setup would be a 2/3AA size cell in NiMH. KAN650 or CBP750 cells are examples of this type. These hold up to 10 Amp loads much better than the AAAs.

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