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Not Enough Battery?

Old 08-16-2005, 05:07 PM
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Default Not Enough Battery?

I've got a Wattage Cobalt 400 mated to the Wattage 2.25:1 planetary gearbox spinning an APC 10x5 E prop. I'm using a 10-cell 1100 mAh NiMH pack of Hecell batteries that is supposed to be able to supply up to 16 amps. With a freshly charged pack, I'm seeing on my Wattmeter 125W with a 12 amp draw and it displays a voltage of 9.4 volts. One club buddy said if the pack was putting out properly, I should be seeing at least 10 volts. He thinks the setup is taxing the pack. The pack is a bit over a year old, but has never been used. It has been cycled 5 or 6 times to bring it up to max, but it has been sitting for 3-4 months. Will a couple of new cycles bring it back to full potency? Or are the numbers listed above reasonable for this setup? Any thoughts? Carlton Campbell
Old 08-17-2005, 02:03 AM
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Default RE: Not Enough Battery?

Well, some of the NiMh`s tends to go to sleep after some weeks needing some cykles to work properly again. But I think your voltage readings is low. Measure the pack after charging, but load it by running the motor for some seconds and remove the load and do the measuring. I think you should read appr 13Volt then (OK, I`m not too experienced on NiMh...) If you measure ex 11Volt you sure have a dead cell in the package. And if you don`t load the batteries you could read as much as 15volt when fresh charged.
Maybe you have to try to measure each cell, and maybe the batteries are out of date.
Old 08-19-2005, 09:34 AM
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Default RE: Not Enough Battery?

125W divided by 12A = >10v. The readings don't tally. Also, 10-cells x 1.2v = 12v (Maybe you can get a bit more as a resting HOC voltage, but not 15v!) I can't see how you can expect readings of 15v even hot off the charger. If you are pulling ~12A from a pack of 1100mAh cells, you can expect voltage under load to drop considerably - to 9-10v.

Cheers, Phil

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