No lipo forum need more help

[bryan]

Flightpower evo25c 5s 5000mah the first cell bleeds into the second cell per the display on my charger.is this repairable, or should i hit it with a sledge hammer and see what happens?????????

[brushlessboy16]

I have no clue what your saying, but sledge hammers and explosives fix everything

[bryan]

I am saying when i chage this battery the first cell intermittently drops to near zero and the second cell climbs to over seven volts intermittently

[Bondonutz]

Sounds like junk to me. Sledge-O-Matic,post video.

[brushlessboy16]

after letting the packs sit for an hour or so what are the voltages like in the cells (use a voltmeter)

[Bondonutz]

I was reading about a different lipo problem in another thread and just wanted to pass this along. Check all the balance plug contacts,dirt,mud could be hindering the reading ???

[brushlessboy16]

yeah I know that my charger flips out and does the same thing ( reads double voltage on one cell and 0 on another) if the balance wires are not in the correct order

[bryan]

I dont know if i checked this right but my voltages are3.71,7.41,11.14,14.85,18.57, i couldnt get an individual cell reading on any but the first.icharged my other flighpower tonight w/no problem

[Patrick]

From looking at your voltages the individual cells are:
1) 3.71v
2) 3.7v
3) 3.73v
4) 3.71v
5) 3.72v
Your readings are not individual cell readings, except the first one. 7.41v readings is of 2 cells, 11.14 is of 3 cells etc.
Did you measure that with a volt/multimeter or charger? From the readings you gave the pack looks fine to me. You can figure out the cell voltages by subtracting the previous reading eg. Reading 1 (cell 1) is 3.71v. Reading 2 is cell 1 and 2 combined, so 7.41v minus cell 1 voltage of 3.71v = cell 2 voltage of 3.7v. etc
If you did measure it with a multimeter, then reading 1 must have been from wire 1 and 2 on the plug. Reading 2 from wire 1 and 3, so measure from wire 2 and 3 to see cell 2 by itself. 3 and 4 for cell 3 etc.
If your readings are from the charger then I don't know what that means, but I don't think it has anything to do with the cells themselves.

[BrianG]

Yeah, the cells are most probably ok judging by your readings, but I would suspect the charger or connections.

What I personally suspect is that one of the balance wires is making intermittent contact. So, instead of seeing two cells at 3.7v each, it sees "one" cell (which is actually two) at 7.4v. This could be caused by dirty balance tap connectors, poor solder job (in the pack itself, the charger, the cable connecting the two), malfunctioning circuit, etc.

[scarletboa]

that's what my flightmax 3s lipo did (kind of) and i gave each of the the balance wires going into the pack a tiny tug and sure enough, the yellow one came out. after re-soldering it yesterday, it is back to normal. most people don't like that little "wafer" in the new zippy packs, but it made my life a whole lot easier yesterday.

[bryan]

Checking the wires that way i get 3.71 3.71 3.72 3.71 3.71. Like i said before i charged another battery last night w/no problem so should i suspect an internal short. Does this battery have an internal board that can be soldered on. Thanks

[suicideneil]

Not sure on the Flightpower construction, unless someone else has already dismantled one your only option is to remove the shrink and take a look for yourself.

[Patrick]

My evo25 4900 6s pack did not have a board, and I doubt that your 5000 pack would. You can usually see the balance wires down the side of the pack since they use clear shrink wrap.
I've forgotten, does the 5s pack have a single balance plug or 2 balance plugs?

[bryan]

it has a single plug. im going to open it up and make sure nothing is touching.