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6 volt 2500 ma nimh battery packs

Old 04-24-2016, 05:31 AM
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Default 6 volt 2500 ma nimh battery packs

Hey guys I got a few of these batteries and I
charge them with the old wall wart charger that comes with
the radio. I am wanting to leave them on their all
the time 24 /7 they take a long time to charge at 50 ma 5.75 volt
Anyone know why I cant do this .
David
Old 04-24-2016, 06:00 AM
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Should work.

http://batteryuniversity.com/learn/a..._metal_hydride

http://www.powerstream.com/NiMH.htm

You're charging at .02C
Old 04-26-2016, 08:40 AM
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The wall wart charger needs to have a higher voltage than the battery you are charging..
Old 04-26-2016, 07:53 PM
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I wouldn't do it....in my mind it's just not safe....
instead get a good charger and charge before you go to the field
Old 05-05-2016, 07:58 PM
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Yep.... Spend $30 or so at HobbyKing and get the correct charger. A decent battery charger is one of the best investments you can make in this hobby... as the batteries are the heartbeat of your plane... and a decent charger(again about $30 or so..) will charge your battery in one hour... and you will know its charged... as using a wall-wart style charger you will only be guessing at the amount of charge its taking... especially with a 2500mah batt, and a 50mah charger.. and you won't know when it peaks... whereas a peak charger detects a battery that is full...

So... I see no reason why you can't charge the way you're contemplating.... other then you're taking a very big risk with your plane.... but its your plane... Only you can make that call. I definitely would recommend a better charger though.
Old 05-06-2016, 05:42 AM
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You should have no problem charging with that old wall wart, it will just take a long time to recharge a fully discharged battery. In fact, charging at that low rate is much easier on your battery than the fast chargers are. Even if you get a new charger, when time permits, charge at 0.1C for longest battery life (most charge, recharge cycles for life of battery).
Old 05-06-2016, 08:22 AM
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If your charger does not have enough amps it will never reach full charge. Chargers that come with the radio are designed around the 4 cell 900Mah batteries that come with most chargers. Get a real charger as suggested and don't leave any battery on 24/7 it can damage the battery. You can set a timer to charge a set # of hours per day. Check out these articles http://www.hangtimes.com/redsbatteryclinic.html
Old 05-06-2016, 08:43 AM
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duplicate

Last edited by raptureboy; 05-06-2016 at 08:44 AM. Reason: duplicate
Old 08-07-2016, 06:47 AM
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I use the HOBBICO ACCU CYCLE ELITE. love this charger,,,I have 2 of them,,,,very reliable.
Old 08-08-2016, 11:16 AM
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Hi!
When charging NiMH batteries never thrust a modern computer charger. The problem with those is that the NiMh battery is always false peaking which stops the charging prematurely
Instead use an old fashioned 100-300mAh wall charger, like that you have but a little bit stronger.
Old 08-08-2016, 12:09 PM
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If your Walwart output is limited to 5.75 volts you can leave a 5 cell pack on forever because it will never get anywhere near a full charge.

A 5 cell NiMH pack needs a charging voltage somewhere between 7 and 7.5 volts to reach full charge.

So you need a suitable charger, one that can cope with the required voltage.
Old 08-08-2016, 02:39 PM
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Most of those wall wart chargers put out much more than 7 volts open circuit. When you put a load on it, the internal impedance drops that down. In all cases I've ever seen the wall wart will charge 6 cell Nixx just fine, just takes a longer time as the current drops off when charging the battery with more than 4 cells but does not stop and will provide a full charge given enough time.

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