Battery connection

I have a 3s battery that shows zero volts and I cannot charge it. After taking the casing off, I used a multimeter to check the voltage and all 3 cells are the proper voltage. BUT, the middle cell is not connected to anything, so that most likely is the problem. I think that this should be a simple fix, just solder the pad to the one with the blue wire. Any suggestions are helpful, and you get to see the internal wiring of a battery

Looks like the connection ripped off - I wonder what happened to the lipo…

I did solder/repair/reassemble some lipo packs, here’s a couple of points I think are important:

  • You’ll need special solder/flux - regular solder won’t stick to the aluminum tab.
  • You may also want to use a dedicated solder tip, that stuff is more aggressive than regular flux
  • Try to solder it quickly without heating up the entire lipo too much
  • I try to solder only lipos which are less than 3.8V
  • Cover all other tabs and cables, do everything to prevent a short circuit
  • Keep a fire safe recipient nearby to throw the lipo into in case everything goes wrong (and think about how to move it once it’s blowing up…)

There is no shame in discharging a defective lipo cell by cell instead of trying to fix it.

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Thanks for the info! I thought it was strange that the tab was broken, especially since I hadn’t used it yet.

I’ve been inside a few lipos myself too for repairs or custom projects and always think to myself…
Risk vs reward…
A new lipo is much cheaper than:
A house fire
A trip to the hospital
A lost/ crashed model

Now I’m not telling you not to dive in… just what I would be thinking as I did. First time you solder on one of those tabs… and feel how fast the cell heats up…you won’t want to make it standard practice to modify lipos. Lol

Then why you do not contact the shop you buy the lipo from and ask for a new one.

I hadn’t used the battery for over a month after I bought it. HK doesn’t do returns after that. I’ve tried. Good idea tho

Bad service. I mean HK.