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Old Aug 13, 2006, 08:55 PM
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Wall Charger gets really hot while charging.

I have a Honey Bee FP that comes with a pack of 8.4V 650mAh Ni-MH battery with a wall charger.

On the charger, it says INPUT: 120VAC 60Hz 60mA. OUTPUT: 12VDC 300mA Level 3.

The charger gets really hot after 2 hours of charging the battery. Is this sound right?

What is the max mAh Ni-MH this charger can handle? I'm looking to upgrade the battery.

I also have a question regarding discharging the battery. By end of each run, I just have the battery and 4 in 1 control box connected and the lit kept flashing from green to red and repeating until the battery is totally dead. Is this an ideal way to discharge the battery?

I appreciate any inputs.
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Old Aug 13, 2006, 09:31 PM
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Miami Mike's Avatar
Miami Lakes, Florida, USA
Joined Mar 2003
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Quote:
Is this an ideal way to discharge the battery?
That's a really tough question, considering that there's no reason to discharge the battery in the first place.

Your charger sounds more like a power supply than a battery charger, but assuming that it is a real battery charger, if you use it to charge a higher capacity battery that has the same number of cells, it should work just as well except that it will take correspondingly longer.

Here's something:

http://www.rcgroups.com/forums/showthread.php?t=444936

Quote:
Be warned that you need to keep an eye on your pack while charging. The instruction book suggest about 2 hours or until the pack just begins to get warm.
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Old Aug 13, 2006, 10:55 PM
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feihu's Avatar
Sun City, AZ
Joined Jun 2002
310 Posts
Quote:
Originally Posted by Discusman
I have a Honey Bee FP that comes with a pack of 8.4V 650mAh Ni-MH battery with a wall charger.

On the charger, it says INPUT: 120VAC 60Hz 60mA. OUTPUT: 12VDC 300mA Level 3.

The charger gets really hot after 2 hours of charging the battery. Is this sound right?


I appreciate any inputs.
Does the battery get hot? The charger getting really hot after 2 hrs does not sound right to me also. What does the Level 3 mean? I would suspect a defective charger.
If the battery got really hot after 2 hrs, I would say a bad cell; I would expect the charger to get warm. but not really hot.

And as Mike said, there's no reason to discharge the battery in the first place.

feihu

feihu
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Old Aug 14, 2006, 12:37 PM
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Sun City, AZ
Joined Jun 2002
310 Posts
Did a check last night - set my charger for 300 ma into a 4 cell 2500mah pack. At the first 2 hrs, the charger got hot like a hot potato and the battery was still cool; after continuous charging for 10 hrs, the charger did not seem to get any hotter (seems to have reached it's steady state temp) and the battery just got luke warm.
Had used this charger many times for different batteries but never realized that it got this hot, and there is no indication of component failure. The transformer is the component that gets hot, and its output is 12v at 450ma.

To charge a 650mah pack for much more than 2 1/2 hrs at 300ma could wind up in an overcharge and cause the pack to get hot and even cause the cells to vent and fail. At a lower charge rate like 60 or 70 ma, the pack is able to safely dissipate the excess energy with no damage. When you charge your 650 mah pack with that charger, you might consider using an appliance timer to shut it off at 2 hrs.

Just trying to help.

feihu
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Old Aug 16, 2006, 06:10 PM
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Joined Jul 2006
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Or a better solution to this is to get a good charger?
Something like this??

http://www.bphobbies.com/view.asp?id...60&pid=V626726

Thanks.
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Old Aug 16, 2006, 08:22 PM
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http://www.rcgroups.com/forums/showthread.php?t=556979 ....
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