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Old 10-30-2004, 08:27 AM   #1
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Default Charging Li-Poly

Hey guys,
I just bought a Li-Poly cell (7.4V 2450mah 10-12C discharge rate), and I was wondering if any one who also uses Li-poly cells could give me a base line charger set-up.
I use the GM Commander and it says it can charge Li-poly by adjusting the max-charge rate and the Max end voltage. Where I need help is to what do I set each to. I am not new to RC but new to Li-poly. It is for two cars. A 1/12TC and the new RC18t when it comes out.
thanks in advance.
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Old 10-31-2004, 05:13 PM   #2
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Old 10-31-2004, 10:36 PM   #3
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Unless your GM charger has a constant current/constant voltage mode I would not use it. If you use a LiPo pack on an appropriate charger it is very safe. If you don't you basically have a small firebomb...i'm not kidding!

If you are running LiPo in an RC car be sure you know what the max current your motor/gear ratio combo will pull. A sedan with a 19T motor will see 50 amp+ spikes if you bump a wall under power. You would need a 2s3p pack of 10C 2100Mah cells (7.40v 6300Mah) to safely handle that. FYI, that pack would run a car for ~10-12 minutes at a race pace
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Old 11-01-2004, 12:15 AM   #4
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what would you guys think about using a GFX to charge a 3 cell li po pack if I can keep an eye on the voltage.

I know someone who charged this same pack with a quasar pro and pulled the pack off around 14 volts he hasn't had a problem yet. any opinions. I just hate the idea of having to buy a special lo po charger just for this one pack, I use it as a transmitter battery works awsome.
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Old 11-01-2004, 07:20 AM   #5
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Don't use a GFX either. If it is for a simple tx pack get a simple wall lipo charger they are like $25.
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Old 11-01-2004, 07:48 AM   #6
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I am going to call Horizon today, they are the distributors and they do the repairs and should know exactly how to charge a Li-po cell. I got some good answers from some airplane guys how basically said that you should only charge at the mah rate (i.e. since my pack is 2450mah then it should be charged at 2.4amps) and I shouldn't let it go past 8.4V total cell voltage. Which I can do on my GM Commander so I belive that if Horizon confirms it then I will try it. The Gm Commander is made in Germany and they don't realy explain the way in there instructions unless you are a battery charging genius. SO I say try it outside in a box and if it don't explode then it is OK...J/K I am making sure through Horizon.
Thanks for the warnings though, it is always good to have guys who are honest enough to not let guys put themselfs in harms way.
It is very apprieciated.
thanks,
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