Charge Time
10-05-2007, 08:11 PM
#1
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Charge Time
Hi all,
Bought a new Cessna 747. Came with a nice charger and it even has red led on it. Figured it will eventually turn green or off when fully charged. But haven't seen either.
Its a NiMh rechargeable 9.6v 8AAA-800mAh
Friend at work said this particular battery takes 3 hours to charge (every time).
Is this the case? Is it true? Is this a good battery? I doubt everyone sitting around 3 hours for 10 minute flight time. Has to be a better way.
Charger Info:
Model: HJ-105
Input: AC 110V 60Hz
Output: DC 9.6V 250mA
Thanks.
jd
Bought a new Cessna 747. Came with a nice charger and it even has red led on it. Figured it will eventually turn green or off when fully charged. But haven't seen either.
Its a NiMh rechargeable 9.6v 8AAA-800mAh
Friend at work said this particular battery takes 3 hours to charge (every time).
Is this the case? Is it true? Is this a good battery? I doubt everyone sitting around 3 hours for 10 minute flight time. Has to be a better way.
Charger Info:
Model: HJ-105
Input: AC 110V 60Hz
Output: DC 9.6V 250mA
Thanks.
jd
10-05-2007, 09:41 PM
#2
My Feedback: (1)
RE: Charge Time
If your battery was fully discharged it would take about 4.5 hours to charge up again.
Take your batter capacity (800mA). Multiply by 1.4 (batteries have internal resistance and don't recharge at 100% efficiency). 800*1.4=1120. Divide by the output of your charger (250mAH). So 1120/250=4.48 hours. NiMH are a bit more fragile than NiCD and the AAA size is especially tender. Your charger is essentially a fast charger so do excercise care when charging your pack.
Take your batter capacity (800mA). Multiply by 1.4 (batteries have internal resistance and don't recharge at 100% efficiency). 800*1.4=1120. Divide by the output of your charger (250mAH). So 1120/250=4.48 hours. NiMH are a bit more fragile than NiCD and the AAA size is especially tender. Your charger is essentially a fast charger so do excercise care when charging your pack.
10-05-2007, 09:50 PM
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RE: Charge Time
thanks. 4 hours is a fast charger? I figured that might be a little slow. 
i wanted to drain it, by running the engine as im having issues with this plane i got. just bought it and it wont even get off the ground. just goes to feet and spins out to the right. so i thought i'd hold it and let it spin the propeller to run the battery down. now its screeching loudly. dont know whats up. so i stopped and set it down and walked away. dont want to charge it more (if thats what screeching indicates). afraid im gonna break the thing. maybe something got stuck in engine or something.
thanks for info. so 4 hours really is pretty normal and fast? maybe i misunderstood what you were saying.
i wanted to drain it, by running the engine as im having issues with this plane i got. just bought it and it wont even get off the ground. just goes to feet and spins out to the right. so i thought i'd hold it and let it spin the propeller to run the battery down. now its screeching loudly. dont know whats up. so i stopped and set it down and walked away. dont want to charge it more (if thats what screeching indicates). afraid im gonna break the thing. maybe something got stuck in engine or something.
thanks for info. so 4 hours really is pretty normal and fast? maybe i misunderstood what you were saying.
10-06-2007, 10:57 PM
#4
My Feedback: (1)
RE: Charge Time
A 4 hour charger is not actually a fast charger it itself but when compared to the C/10 chargers which come with most standard radios (which take 14-16 hour to fully charge) it could be classified as a "fast" charger. It's fast enough to use due diligence with your charging times - i.e., don't let it sit on this charger for longer than 5 hours max.
