how did both batteries died on the same day??

[clumpymonkey]

I had to batteries that were half charged (intellect 9.6v 1600mah and 2000mah NiMH) and i discharged them with a batt discharger before recharging them like ive done before, But for some reason the voltage on my batteries has dropped super low. To around 2-5 volts for each pack, and my charger wont recharge them.

Any takers on whats happening?

Discharger is a Guarder AEG bat discharger: for 4.8-9.6v NiCD/ NiMH discharging current : 1A

Charger is an MRC Superbrain 960

First time this has happened too.

[clumpymonkey]

Forgot to mention that my 2 mp7 batteries also wont charge.... im starting to think its my charger.

It wont peak voltage (voltage stays the same as it started) and itll say thats its finished about 20mins from starting (goes from not charged to fully charged instantly)

Is it the batteries or is my charger hooped?

[theguy]

You shouldn't discharge Nihm batteries, Only NiCad.

Discharging NiHm will wreck them pretty fast, thats probably your problem

[Drake]

Sounds like you overdischarged them. Even NiCads shouldn't be fully discharged if you plan on storing them.

If your voltage has dropped that low on a pack you most likely have at least once cell that reversed polarity (i.e., it's now a negative voltage). Most smart chargers cannot cope with that. Trying to force a charge into the pack with a dumb charger may fix it, but it can lead to the cell exploding/catching fire. I wouldn't recommend going it if you don't know what you're doing; maybe you can get help from an R/C shop or something.

Considering most batteries don't cost that much, you may want to just replace them. (At this point, those packs are toast).

As for the MP7 packs, do they also show an abnormal voltage? (they're 7.2v packs if I'm not mistaken) ... they should show between ~5 and 8 volts on a voltmeter. Make sure you charger can handle 7.2v.

[clumpymonkey]

Thanks guys (and stupid me) as with the mp7 bats, ive managed to get them working again using the charger that it came with.
no fires or explosions yet!

[clumpymonkey]

went to the hobby store and had my batts checked, they all got A+, and got my charger checked out, its crapped the bed! haha

thanks for the advice

[kalnaren]

You don't even need to discharge NiCads under normal use conditions. Once upon a time it was true, but modern batteries have increased in quality so much the memory effect has been virtually eliminated in NiCad batteries.