puff puff the magic smoke. Why?

ken1645

10 W
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May 2, 2013
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Location
Houston, TX
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Why did this just spark up the 4mm bullet connector and short it out? I don't see why it would have shorted.

Was trying to charge 10s2p on my thunder charger but when I connected the + and - together to get the 5s into series to make 10s it smoked up... now I gotta resolder on some more connectors. I'm getting quite good at it now though which is good.

Thankfully these connectors burn them selves until they aren't connected, the batteries appear to be fine, each has 3.93V on all the packs..
thx
 
Could it have been capacitors not being pre-charged?
 
liveforphysics said:
Could it have been capacitors not being pre-charged?
hmm don't think so, it was just batteries connected to batteries. No caps. I had the 4 batteries about ready to charge.. I did have the balancer plugs plugged into the charger of all 4 battery packs.. maybe that was my flaw.

Anyways I'll stay away from charging in parallel for a while I suppose. I don't think my diagram above is flawed.
 
Or the packs were paralleled at the cell where you didn't expect?
 
You did parallel the paralled packs balance wires? The Thunder only has 2 ports for Balancing. If they are backwards (first being negative and 2nd for positive) you should just get an error message, not sparks. Did you try to parallel the series connections balance connecters? Just guessin' but I dont see why sparks should appear.
otherDoc
 
@ken1645 - Let me ask you some couple question.

1. Did your main lead connector hooked E.g. controller or charger before you hooked the series wiring?
2. Did you parallel (A) LiPo pack before you hooked (B) LiPo E.g. 10Ah vs 5Ah
3. Does both paralleled packs fully charged (different volt from A to B probably will spark)
4. Did you paralleled balance lead together (A and B) before hook up the series? This will spark for sure.


These list above will cause you spark when you hooked series wiring. I always do first paralleled A and B packs in complete fully charged as equal voltage before going series. I never get any spark as long as the main lead connectors isn't hook or shorted somewhere.
 
ken1645 said:
liveforphysics said:
Could it have been capacitors not being pre-charged?
hmm don't think so, it was just batteries connected to batteries. No caps. I had the 4 batteries about ready to charge.. I did have the balancer plugs plugged into the charger of all 4 battery packs.. maybe that was my flaw.

Anyways I'll stay away from charging in parallel for a while I suppose. I don't think my diagram above is flawed.


Sounds like you had balance tap plugs combined so you were putting the cells in parallel, then attempting to put them in series with the discharge leads, which is the same as just mashing positive to negative.
 
If the paralled balance hooked and the main series wiring will spark and the balance wiring will be very hot.

Only it will vaporize the balance lead hook up while the main wiring is on series hooked.

That's what I noticed the ES member mentioned in past.


migueralliart said:
But wouldn't that just evaporate the balance leads? Those are what 22ga cable.
 
chroot said:
@ken1645 - Let me ask you some couple question.

1. Did your main lead connector hooked E.g. controller or charger before you hooked the series wiring?
2. Did you parallel (A) LiPo pack before you hooked (B) LiPo E.g. 10Ah vs 5Ah
3. Does both paralleled packs fully charged (different volt from A to B probably will spark)
4. Did you paralleled balance lead together (A and B) before hook up the series? This will spark for sure.


These list above will cause you spark when you hooked series wiring. I always do first paralleled A and B packs in complete fully charged as equal voltage before going series. I never get any spark as long as the main lead connectors isn't hook or shorted somewhere.
#4 yes I had done that. I did not realize the balance leads needed to be hooked up last. Valuable lesson, glad that the batteries survived. Took em out for a ride today and they're doing great.
 
We ALL belong to the KFF club brother. Welcome. I did it again myself just the other day. I run 14s now, and was putting together another pack with some 5s and 4s. So I built a 14s pack from three 5s and one 4s. 19s, which didn't like being plugged parallel with a 14s pack. Killed some tabs in the 4s packs that were the + end.

Uhh, how did I manage to do one that stupid?

What was the question again? Chronic fatigue could just as well be called chronic stupid. Tired is dumb.
 
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