Chad22

iTrader: (8)

Hey guys,

I have a 6 cell Intellect 4200 Nimh pack that i hadn't used in about 6 months. I went to charge it the other day and the voltage has droped to .89V and won't charge higher than .2 amps!!

Is my pack finished? What can i do to bring the voltage back up? I tried charging it for several hours at .2 amps and still the voltage won't go past .89V

Thanks for your help guys!

burnineyes

iTrader: (17)

Its likely toast if it is taking a charge and still not increasing. What are you charging it with? In the interest of safety, many decent chagers may not do what the pack needs.

tc5 man

when u charged the intellect battrie did it get hot cause they wont last a long, time if so , i have a intellect 1400. in my rc18t and after a while if it gets. quite warm at least one cell goes bad, did u equalize it that helps it a lot.

B4power

iTrader: (4)

The batterie is probably no good anymore. The reason is when you don't charge a battery for a long time, it cannot take it's charge anymore. It's the same thing as a 1:1 car battery. So the next battery you have, you should charge every mounth.

Duster_360

iTrader: (21)

Sometimes shocking a batt in this condition can get it going again, try 5amps for 1 - 2min, then see if it'll accept a charge (I'd start with a low rate and let it continue toa while).

Store NiMhs fully charged if they're going to just sit and re-peak them once a month.

tom_chang79

iTrader: (13)

I didn't use my NiMH for about a year and half. You just have to keep at it, force charge it a bit (motor run in), then try peak charging, if it fails, keep force charge/trickling it with the motor run-in... For motor run-in, just make sure you raise the voltage HIGHER than the pack's voltage...

You can wake it up, it just takes a bit of effort...

If it starts and ends peak charging, and the capacity isn't up to par, just cycle it a few times, it'll start to take more and more charge...

Just make sure you cool the battery between the cycling... Peak charge it, discharge it, peak charge it again...

Chad22

iTrader: (8)

Thanks for the help guys!

I'll keep trying and hopefully get this pack to life

burnineyes

iTrader: (17)

Like Duster said, shocking them can bring them to life sometimes.
Soemthing I DO NOT RECOMMEND, but I have done before is this.
set the pack on a table and cover it with a heavy cloth, so that if it explodes it will be somewhat contained.
Shock the pack with an automotive battery charger at 12V 40amps for a few seconds at a time until the pack is very warm. This is very stupid and dangerous and again I do not recommend anyone do this. But it has made some completely dead packs perform great for another 6 months.
If you do decide to act stupid like I did, please take precautions and wear protection. And dont do it in the house. In fact just buy some new batteries!

Duster_360

iTrader: (21)

^^^ I've got a pr of dead 8 cell packs that I've not been able to revive no matter what I've tried, I might just give that a try.

burnineyes

iTrader: (17)

Im sure you have seen nimh blow up before, so I dont have to tell you to be careful. Back when I did that I had seen lots of them vent, but never explode. Not long ago I had a charger malfunction and explode 2/3 A nimh packs in my house. I think I would not have tried that trick if I knew what they could do!

Duster_360

iTrader: (21)

Seen them vent and have seen them blow as well. If I do try, you can count on it being done outside and either in a container or as you suggested, wrapped in a heavy blanket.

TY@TEAMTEKIN

Check all the cells individually, you most likely have some badly reversed cells. Shocking the pack all at once won't do much good if you have reversed cells, you need to balance them all first and then try to wake it up.

Sounds like you need a Battery Nurse for them NiMHs!

cbr74

iTrader: (14)

Guess they don't make them like they used to... I had NiMh that'd sat for years and were so dead the charger wouldn't even recognize them. I gave them a little boost with a fresh pack and then threw them on the charger like a normal battery and they all came back to life.. did that with four of them. Go figure.

burnineyes

iTrader: (17)

I too have seen many nimh packs come back to life with a small boost, but when times are hard and that wont work Ill try some crazy stuff. And Tekin is right, if any cells are reversed it wont do much good zapping the whole pack. I would be weary of doing it to any stick pack anyways, those melt way too easy.