Lipo repair
 

I figured that I would start this thread as I have had quite a few questions recently about lipo repair.

Most lipos can be repaired, such as having a bad cell removed or physically repairing damage to the wires (main or balancer wires).

I can combine cells from different packs to make a higher voltage pack, but I will say that they may not stay in balance if the cells were not factory matched. If one cell is older or had more use (cycles) than another it may not hold the same capacity or voltage. Generally I find that cells from the higher quality packs (enerland cells) do not mind being mixed and matched.

If I am making a larger pack from 2 seperate packs I will individually charge the cells before assembly, and cycle the pack to make sure it works correctly.

For example: If you have a 4s packs and want a pair of 2s packs that would not be an issue. I can also make a 4s pack into a 2s2p pack, half the voltage but twice the capacity. Also I can take a 2s and 3s pack and make them into a 5s pack. These are both examples, but should cover most of the requests I receive.

Also, if you have a pack that has dropped below 3v per cell, and the cells have not puffed, I can most likely get it to work again. I will not gaurantee this, but I have had good success so far.

IF THE CELLS ARE PUFFED THEY ARE GONE, DO NOT TRY TO CHARGE A PUFFED CELL! Sorry for yelling, but that is important.

I have also found that a pack with a dead cell (0v on that cell) that still reads voltage on the main wires may have other issues due to the dead cell still being connected to the reat of the pack. Leaving a dead cell in there does not seem to be good for the other cells, may even pull their voltage down. So if you have a problem pack, and want me to fix it, quickly sending it to me is your best bet.

Also, I have never had a lipo catch fire, explode, or do anything other than puff. I have never over charged a lipo, which seems to be the method to make one explode. So don't do that either. Also do not try to "jump start" a pack by using a timed charger or other dc power source. Leave that to the pros (me) who are stupid enough to do it:yes:

If you plan to ship a lipo to me, wrap it up in a good amount of foam or bubble wrap and put it in a sturdy cardboard box. Make sure it is a tight fit so it does not rattle around during shipping. Lipos are not fond of dents and dings...

Hopefully this will answer most questions... If you have any questions please post here, as the info will help others. I will have a link to this thread in my signature. If you would like to send me a lipo for repair please PM me for address info. I do keep a decent stock of shrink, wire, and balance connectors, so repairs can usually be done in a few days.

Good info linc!

Also I will list the brands of lipos I have already repaired, and should not have any trouble with.

Any enerland cell based pack (ie, polyquest, polyrc, flightpower, neuenergy, hyperion, etc)

Maxamps (all)

Zippy

Thunderpower

Venom

Most chinese packs

All of these use aluminum or copper tabs and I have the required products to solder to them.

I generally protect the ends of the lipo with something solid, such as thin sheet plastic. I also completely wrap the pack in clear tape. This holds everything together, prevents cell shifting, and gives the pack a bit more protection. I use black shrink as I can get it easily, and most like the look of it.

Note: I recently had a protek pack sent to me with a puffed cell. They encase the contact end of the lipo with some sort of nasty glue. I was able to remove enough of this stuff to access the solder tabs and balancer wiring, but it was a bitch. So I charge a bit more for those packs and cannot gaurante that I can fix them, as the glue is much stronger than the al tab. This is delicate work and that glue needs a bit of muscle to remove.

i kinda liked the rubber dipped ends on my proteks linc but i havent had any trouble it seems to be a great way of keeping all the wires tucked away and from shifting on the end of the pack... and i bet it is a bitch to get off and keep the tabs intact

It was nearly impossible to do. I ended up scratching the stuff off with my fingernails. Only way I could see to do it without harming the tabs...

them aluminum taps are a bitch too. I repaired a few of mine and i have the correct solder and flux and still hard to get to stick. All i can say is VERY VERY CLEAN taps will do the trick.
hey linc- you notice that the zinc flux smells kind of like rabbit piss? :lol:

I don't wanna know... :whistle:

Never drank rabbit piss myself... but the zinc flux does smell bad.

What does rabbit piss go well with? Does it pair well with red meat or fish? I usually prefer wine with my meals, but that is just my preference...

There's an easy solution for that - don't breathe when you're using it :angel:. That smoke cloud that comes the flux, on the other hand, is something else.

Hey Linc, what's the best method you've found for using the zinc flux and solder?

I've soldered for years using Dean's solder, but I've never had to use flux and solder separately before. I'm splitting a 5s 5k Neu pack into a 3s and 2s configuration.

I'm going to look it up, but I figured I'd get your professional opinion as well.

Very good info Linc :yes:

Its often used to attract coyotes...I once had a welding professor who had a full size rabbit costume that he dressed up in to go coyote hunting. He'd soak it in rabbit piss, wihich you can actually purchase. Trappers and whatnot buy all sorts of stuff like that for disguising scents.

well now we all know if we want to attract coyotes to our bodies is to cover ourselves in zinc flux instead of rabbit piss. actually, if a coyote comes and attacks you, it might decide not to eat something that tastes poisonous.

So everybody wins?:na:

i have a 4s 3700 i got from mike that says anyrc.com on it that has a strange proble,
everything seems normal.pack is hard and flat,charges corrctlly and is in balance butit has no power at all. if buggy is geared for 40 mph with this pack it will go 10mph full throttle. wont even rev up enough to have trouble making full speed turns on the street it is that slow. what you think?