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Need help on charging TX battery

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Old 07-07-2004, 04:48 PM
  #1  
tengler
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Default Need help on charging TX battery

I got a used Futaba Conquest with a 500 mA battery. It cycled successfully by the seller and the charge lasted for a couple of hours above 70 percent. I let it run down to 40 percent on the charge dial and now want to recharge it. I have a 50 mA slow charger (cheap wall plug in) that has no peak detection and I also have a Hitec CG-340 field charger that I could use at .2 Amp rate which is the minimum. I think that's 200 mA rate. The supplied Futaba battery says you can charge it at 50 mA for 15 hours or quick charge it at 150 mA for 5 hours. Question, can I use the 200 mA quick charge on the Hitec charger as long as the batteries do not get hot? The charger instructions say you could use up to 1 amp rate for a 500 ma battery if it doesn't get hot, but of course I would use the lowest setting only (200 mA.) The advantage is that the Hitec is a peak detection charger and will turn off at full charge. I realize this battery may not be in the best shape, but as long as I use it for a couple hours safely I will upgrade later. Also, if I use the 50 mA charger, can you overcharge the battery? Thanks for any advice from anyone. One more quickie, the seller gave me another old Conquest with no battery inside, can this be used as a buddy box without battery?
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Old 07-08-2004, 08:15 AM
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Rodney
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Default RE: Need help on charging TX battery

Use the 50 ma charger and no, you won't hurt the battery by overcharging if you use that charge rate. I'm curious as to how you determined the 70% figure. On NiCads, the voltage readings do not correspond to %, the only reliable way is to measure the amperehours left in the battery by doing a timed discharge at a known load until the battery is down to 1 volt/cell.
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Old 07-08-2004, 03:27 PM
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Default RE: Need help on charging TX battery

the answers are yes and then no
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Old 07-08-2004, 09:29 PM
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Nogyro
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Default RE: Need help on charging TX battery

Check out Reds Battery Clinic at http://www.rcbatteryclinic.com/ Lots of good pratical info here.
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Old 07-08-2004, 09:58 PM
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tengler
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Default RE: Need help on charging TX battery

Thanks guys. I don't have any equipment to measure batteries strength yet, I guess that is my next purchase.

Rodney, what happened was that the seller is helping me learn to fly an almost new Big Stik 40 I bought from him. (I have much airtime with a Sky Scooter Pro.) He added Conquest transmitter to the purchase.

He has cycled and variable amp charged the battery. After the one test flight he told me to keep the keep the Tx on see how long it took to get down to 70% on the dial. It was about 2 hours.

I decided to recharge on the 50 mA charger for about 15 hours. As another test, I turned the Tx on with throttle open and occasionally worked the other stick; again it took about 2 hours to run down to 80% on the battery dial.

Would this mean it is safe to use this battery for about 2 hours? How far down on the battery meter can you safely fly; to 80 or 70% on the TX meter? Or...Do you recommend buying a new battery. Thanks for all your help from this new guy.
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