Lipo Repair (Short Circuited)

by FSMultirotors | October 12, 2013 | (5) Posted in How To

 ****DISCLAIMER****

WHEN WORKING WITH LITHIUM POLYMER (LIPO) BATTERIES, SAFETY IS OF GREAT IMPORTANCE. THIS MUST BE DONE WITH GREAT CARE AND ON A NON-CONDUCTAVE WORK SURFACE. YOU MUST WARE PROPER SAFETY EQUIPMENT INCLUDING GOGGLES AND GLOVES. I CANNOT BE HELD RESPONSIBLE FOR ANY INJURIES CAUSED BY ATTEMT OF THIS PROCEDURE.

 

While working on a project, I accidentally shorted out a 2 cell Turnigy 1000mah lipo. Rather than buying a new one, I was curious to see if I could repair it. It turned out that it was a very simple fix, a broken wire connecting cells, due to the short. I thought that others could benefit from learning how I fixied mine, because shorted lipo's are a common problem on smaller C rate packs. Although this was done on a 2s Turnigy 1000mah, it works with almost every other configuration of lipo's.

Step One: Ready the Tools

To fix your lipo you will need an X-acto knif, a soldering iron, and safety gear (googles).

Step Two: Cut the Outer Casing

Place your lipo on a non-conductive surfact

Using an X-Acto knife, cut the Lipo's outer casing from the back. Make sure to place the knife under the casing, with the blade facing upwards. Apply upwards pressure.

 


Step Three: Remove the Lipo Pack

Step Four:

Remove the white protective plastic slip


Step Five: Find the Problem/Wire Break

In my case, the blue wire, cell #2, had a broken contact soldered to it. This was caused by my short circuit.Step Six: Repair

Use a soldering iron to repair the broken contact(s)Step Seven: Cosmetics

First, replace the white protective slip. 

Second, re-wrap the pack with the outside casing. In my case, I used a strip of velcro to hold it together on the back because I secure the Lipo to my plane with velcro anyway. 

 

 

 

 

 

 

 

 

 

 

 

COMMENTS

Sirglider on October 16, 2013
I like the idea of repairing stuff instead of throwing them away, but please, put a huge warning at the beginning, because when I see your photo with your knife cutting the cover of your LiPo, I can already imagine dozens of exploded LiPos of people trying to do the same as you do... Don't do it if you are not of what you do and are not protected. It can really hurt!
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FSMultirotors on October 16, 2013
Thank you for your concern. I had an intention to include a disclaimer/warning in the beginning, but I did not expect flitetest to approve this article so quickly. I have added the disclaimer and revised the procedure for cutting the outer casing.
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tramsgar on October 16, 2013
Just because it can be done doesn't mean it should be =). IF anyone tries this, never ever cut the outer casing that way, use a nail scissors or some other safe way...
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MountainSnowFlyer on October 22, 2013
I agree! I accidentally sliced through the foil cell casing with an exacto knife releasing the "magic" white smoke. I just barely got the pack outside before it burst into flame. It was a 4S 4000mah battery too....so a lot of stored power and a big bummer!
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FSMultirotors on October 22, 2013
Although that can happen, it will not happen if you used the method for cutting the outer label that I specified. I said that it would be best to put the x-acto under the label, and apply upwards pressure. Better luck next time.
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Chad on October 16, 2013
Great tip and easily done. The outer casing every one has mentioned is only heat shrink with a label and can be easily removed and replaced later as many hobby shops sell it.
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krisrilee on October 16, 2013
this doesnt always work tho. sometimes you cant get the solder to stick to the tabs.
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lonewolf7717 on November 3, 2013
oh my.....my my my.
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bstarkey54 on November 13, 2013
I tried to fix my lipo but I don't know what type of solder to use. My regular solder flat wouldn't stick. What type do you use and where do you get it. Thanks!
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FSMultirotors on November 13, 2013
The solder type doesn't really matter... All you need is solder flux. Once the tabs are tinned, it is very easy to solder them. Not all flux works, as we are working with aluminum.
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Lipo Repair (Short Circuited)