Battery issues / Mechbox?

[Azathoth]

I have an interesting problem.

My gear
1 Stock TM M4 S System
1 Sanyo 8.4v 600mah NiCD – 7 cell
1 Intellect 9.6v 1100mah NiMH – 8 cell (I know it doesn’t fit, I’m rebuilding the pack)
1 Intellipeak mini pulse charger Link: http://www.duratrax.com/caraccys/dtxp4100.html

I tested the batteries when they arrived and it had approximately between 2/3 and 3/4 charge remaining. I saw this as a good opportunity to condition the battery before use and test my AEG.

My short term plan is to relegate or replace the battery almost immediately as 600mah just isn't enough.

Anyways back to the problem. I connected the Battery and test fired the AEG on Semi. All is perfect. I then test on Full Auto. Again all is perfect. I take a little time to adjust the sites and hop-up, and repeat my test firing until both batteries gives out. I'm satisfied that the AEG is in working order and I proceed I plug in my battery to charge.

I charge the Sanyo for 7 hrs on the slow charge. I don’t bother testing the battery and proceed to connect and test AEG/Battery.

Pull trigger and nothing, not even a little effort from the box. I assume the battery hasn’t been sufficiently charged and check it. Upon connecting the battery to the tester the volt meter goes backwards into negative territory (yes +ve to +ve, -ve to –ve). I reverse the connectors +ve to –ve and it shows a ~80% charge.

So what now? Have I fried the box? Did I Incorrectly charge the Battery? Do I have a bad charger?

Any help would be greatly appreciated.

[ThunderCactus]

If it's not making any sound what so ever, and your tester says theres voltage in the battery, it's a wiring problem in the gun. Try checking the fuse first.

[mcguyver]

Likely you've reversed cell polarity. This can occur from charging in reverse polarity. Perhaps the batteries were manufactured with the (+) and (-) wires incorrectly attached. This often happens with packs built by thumbless monkeys at battery shops.

Not all batteries blow up when charged revers polarity. Many will take the partial charge, but with no current capacity.

Recheck your pack, cut the heatshrink off it if necessary. The indented end (if apllicable) or with the central contact is the positive. Follow the path from positive to negative throughout the pack to see if their wiring is correct.

[Azathoth]

Originally Posted by mcguyver

Likely you've reversed cell polarity. This can occur from charging in reverse polarity. Perhaps the batteries were manufactured with the (+) and (-) wires incorrectly attached. This often happens with packs built by thumbless monkeys at battery shops.

Not all batteries blow up when charged revers polarity. Many will take the partial charge, but with no current capacity.

Recheck your pack, cut the heatshrink off it if necessary. The indented end (if apllicable) or with the central contact is the positive. Follow the path from positive to negative throughout the pack to see if their wiring is correct.

I tested the battery at a local battery world and it was -ve charged (coulda been me or the batter). however there voltimeter read -0.57v.

Now with that in mind. Why doesn't my other battery seem to want to power my box? The same people tested the 9.6v battery and it read 7.07v. That *should* be enough juice to make the box try and cycle right?

I'm hoping that my charger which claims to be intelligent did not charge my battery beyond -0.XX (which smart chargers are for to prevent stupids like this from happening). If that's the case then I don't think I did any damage to the box and I can get away with a blown fuse. However i didnt smell anything out of the ordinary.

I'm told by the experts that if you -ve charge a battery and put it into a purely mechanical device it will either

A) blow the device
B) It will run backwards.
C) Nothing Happens.

[mcguyver]

Originally Posted by Azathoth

I tested the battery at a local battery world and it was -ve charged (coulda been me or the batter). however there voltimeter read -0.57v.

That tells me the battery is dead. Toast. Likely unrecoverable, unless you have a swanky charger that can do charge/discharge cycles (controlled), but even then, it's iffy.

Originally Posted by Azathoth

Now with that in mind. Why doesn't my other battery seem to want to power my box? The same people tested the 9.6v battery and it read 7.07v. That *should* be enough juice to make the box try and cycle right?

If the battery was very near dead, at rest, it should still read 9.6v or close to it. That is the potential of the cells in series, 1.2v per cell x 8 cells. If any of those cells individually are toast, you will get a much lower reading than 9.6v, and likely the entire pack will not pass enough current to even turn your gun. It could be that the pack is entirely dead, and a recharge can bring it back to life, but no guarrantees there either.

Originally Posted by Azathoth

I'm hoping that my charger which claims to be intelligent did not charge my battery beyond -0.XX (which smart chargers are for to prevent stupids like this from happening). If that's the case then I don't think I did any damage to the box and I can get away with a blown fuse. However i didnt smell anything out of the ordinary.

I'm told by the experts that if you -ve charge a battery and put it into a purely mechanical device it will either

A) blow the device
B) It will run backwards.
C) Nothing Happens.

Hard to say. Not all chargers are built the same, nor are all batteries. But a battery reading -0.xx volts when you have marked polarity correct to meter, that's not a good sign at all. I'd be talking to the twit that made the battery, then order one pre-built from an airsoft retailer or some e-retailer who builds pack for airsoft/RC use.

[Azathoth]

Funny thing is I did order these batteries from a reputable airsoft dealer (redwolf).

[Omi-san]

I got one shitty battery from Redwolf once. An intellect 1200mAh battery which lost all its charge in the hour following the peak charge.

[Azathoth]

Originally Posted by Omi-san

I got one shitty battery from Redwolf once. An intellect 1200mAh battery which lost all its charge in the hour following the peak charge.

Issue resolved.

The Tami plug adaptor that I use to connect my charger to my battery has the +ve and -ve in the wrong terminals. By reversing the terminals everything was good.

Also. I will have to highly recommend the charger that i own. It's smart, too smart. It didn't put a -ve charge onto the battery instead draining it. And when I attempted to attach a voltimeter to the charger to test that it worked it refused to pass a current to the meter. But when a compatable battery was plugged in it would work. I had to splice the cables to test that the charger was putting current to the battery pack.