Damaged Lipo plug?

[Nightshade]

Hi Guys,

I just went to clean my car after last meeting. I picked it out of it's box and there was a little crackle and a puff of smoke from the balance lead of one of my lipo's. It looks like the plastic part of the balance plug has come off during the last race and two of the 3 balance wires were touching each other.

I pulled it straight out of the car and put it outside, then snipped one of the balance wires further down so they were no longer shorting. Do I need to just bin the whole battery? It's a turnigy one where all the wires disappear into the hard case, so they can't be changed. Can I solder a new balance plug on, or use it without balancing and seal the wires somehow? Or should I just bin the whole thing?
I have no idea about lipo's...

[leeleefocus]

The wires shorting will not of done any damage to the lipo. The wires are not big enough to put a load on the cells that would cause any damage.

I would definatly solder another balance connector on unless you are going to manually monitor and balance your cells.

Hopefully they havn't desoldered from the cells.

[NeilRalph77]

I think Panks got some plugs coming, should be at cullingworth friday save you buying one.

[mark christopher]

Originally Posted by leeleefocus

The wires shorting will not of done any damage to the lipo. The wires are not big enough to put a load on the cells that would cause any damage.

I would definatly solder another balance connector on unless you are going to manually monitor and balance your cells.

Hopefully they havn't desoldered from the cells.

so how many amps will those wires carry?

[Nightshade]

Sounds good - that's my good battery don't ya know?
Give him a nudge if you see him, and I might call on your expert soldering skills (was that an offer??)

[leeleefocus]

It's a Turnigy hard case so the balance wires should be 24awg with silicone insulation giving it a maximum current carrying capability of about 10A. This is the absolute theoretical limit of this wire.

If dead shorted the current will spike higher than this before the wire goes open circuit but it will be long before it reaches the maximum current the lipo is capable of.

[dobber]

Originally Posted by leeleefocus

It's a Turnigy hard case so the balance wires should be 24awg with silicone insulation giving it a maximum current carrying capability of about 10A. This is the absolute theoretical limit of this wire.

If dead shorted the current will spike higher than this before the wire goes open circuit but it will be long before it reaches the maximum current the lipo is capable of.

The maximum continual rating may be 10A. This means the cable can handle 10A without damaging it or the insulation. In a short circuit situation the cable will act like fuse wire. It will carry the full load fault current until the cable basically melts and therefore breaks the circuit.

[mark christopher]

Originally Posted by leeleefocus

It's a Turnigy hard case so the balance wires should be 24awg with silicone insulation giving it a maximum current carrying capability of about 10A. This is the absolute theoretical limit of this wire.

If dead shorted the current will spike higher than this before the wire goes open circuit but it will be long before it reaches the maximum current the lipo is capable of.

Originally Posted by dobber

The maximum continual rating may be 10A. This means the cable can handle 10A without damaging it or the insulation. In a short circuit situation the cable will act like fuse wire. It will carry the full load fault current until the cable basically melts and therefore breaks the circuit.

gold star for dobber........ lee take some 10 amp rated wire and with a very good ampmeter see what it peaks at before it goes open circuit, and dont forget if its not a full short (le low discharge)it could discharge just one of the 2s cells! as its the balance port, assuming the cell is ok is a bold claim

[leeleefocus]

Hold my hands up I have over looked the possibility of a partial short. if it was a dead short with24awg wire it will not damage the cell/s of this particular battery.

[leeleefocus]

Only way to monitor that current is with a shunt and an oscilloscope.

Just been in the garage and dead shorted a 5000mah turnigy hard case Lipo with some 24awg wire multiple times. tried to measure voltage drop but my meter doesn't have the resolution. it fuses in less than a second.

the cells will not be out putting maximum current because of the resistance in the wire. which be a considerable amount on 24awg wire about 20cm long
Circuit length.

[Nightshade]

Last 5 posts


-> Nightshade's head

So are we still thinking it's ok??

[leeleefocus]

Check the cell voltages through the balance wires. if the cell voltages are above 3v then put a balance connector back on it and give it a balance charge and your good to go. if you can't get a reading through the balance wires then you have melted one of them.

What I would say then is repair it or sell it to me for £5+ postage