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?

Somehow I have missed all the posts on this thread... Whoops!

The best method I have found is to smear a small amount of the flux on the tab, then tin the end of the soldering iron with the zinc flux. When you touch the iron to the tab it will liquify the flu and the solder should flow onto the tab. I use a reasonably wide chisel tip on the iron and keep it on the tab with a swirling motion to make sure that the solder spreads evenly.

Do you have another lipo to try? May not even be the battery.

How do you charge the lipo? What balancer and charger do you use? Do you have a volt meter? Also what motor and esc are you using?

lincpimp ygpm

Just figured that I would update this thread with my recent repairs.

I have now repaired all of the various hard cased lipos. So I am familiar with how they are setup internally, and most inportantly, how to get the cases open with out damaging the case or internal wiring. So heres a list,

All losi hard cased lipos

Enerland hard case

Orion/kokam hard case

Trakpower

And the cheaper ebay chinese cell hard case lipos

Not sure that I put this anywhere else, but please post info here or pm me. I leave pricing to pms, but repairs usually take a day or so and I can ship back the lipo. Payment can be made via paypal or thru MO/cash.

And as always I am interested in buying damaged packs that you may not want, I only ask to have a look at them before we settle on a price. I will also pay shipping for this.

Thanks for all the interest, and I hope I am providing a somewhat useful service...

Lincpimp really knows what he's doing. My Losi pack had died an untimely death and lincpimp was able to take the pack apart, fix it and make it stronger than it came from the factory. Thanks again for saving my pack.

I bet you can't work your magic on these.


http://img255.imageshack.us/img255/5227/dsc0165kv6.jpg

No prob, you are very welcome. I can fix most problems, and will be happy to look at anything sent to me, free of charge unless you want it fixed!

Looks like you have 1 good cell, bottom one on the left pack... Othwise they may be gone...

Now you can try flattening the ends back and resealing them... I have am in the process of testing this on a torn cell... I am not in the charging phase yet so try at your own risk!!!!
I will post back results...

So It Happened......
 

Linc I'd like your input on this- first off, I was under the impression that the Maxamps 2S 6000 were a 2 cell, they're 4 with 2 paralleled. So my first thought is how the hell can you balance these at all with their setup :drunk:

So I ran my packs down to about 7.1 on one run- not even close to cutoff, they flatten out enough that it's noticeable anyway but sure enough one is a little swelled- kinda knew it'd come with all the fun stuff I've read about Maxamps, but still it blows- especially considering I had to send 2 packs back a few months apart to GET two packs that were good. The first order one pack was at 4.2v, went back immediately, then a few months went by and the third one wouldn't balance, it was long enough that they felt the need to charge me more for the fourth replacement, so I paid around 3 bills for two packs- don't I feel smart for not finding RCM sooner..... the real issue was fitment in my mute, it was built for 6 cell packs and I had few options, but never again...

Anyway rant over, do you think this is ok to trial run? I charged it up full and it is balanced, but I wonder if it's worth trying. The other thing is these like peckmarks around the perimeter of the puffing, have you seen that alot? And the bottom cell seems very slightly puffed, should I just dispose?

They are all punctured. I'm just going to trash them. Its not really worth it to try and keep them. I only paid 50 or so for the set. I might wait an see what happens to your packs though.

Hmmm, your pics are not really clear enough, can you take a pic on the side of the pack so I can see how puffed the cell is?

As for paralleled cells, they will work properly if and only if they are matched correctly. Maxamps told me they matched their cells, and I say that they are full of shite. I had a tech at flightpower explain their multi step matching process...I doubt that maxcraps has anything like that.

So my advise is to sell the maxamps packs that are still good. If your setup is ok with those packs, a pair of trakpower or other decent enerland hardcase packs will do fine, even at around 5000mah. Those will outperform the maxamps 6000 packs, which are 15c packs at best.

Stay away from parallel packs, only decent ones I have seen are the true rc 8000 packs.

They most likely puffed due to over discharge, and poor matching. The weak cell in the paralleled pair could not handle the discharge amps and most likely puffed due to that.

The photo on the left is the upper cell, pic may have exaggerated the puffng a bit, it's about 1/8 inch, and about half that on the lower cell.

It is likely that some of the swelling has actually gone down already. My MA packs usually swelled big, then deflated over time, only to swell again upon use. Dangerous game to play, I know. :-)

It actually has stayed the same kulangflow, which is why I am (stupidly?) considering trying it, I am in denial--- these packs have less than 30 cycles on them and I have treated them like china... grrrr I don't want to put .22 holes in this pack yet!

But then I do- knowwhatImean?

Well, once they puff they are done. You can try running it, but it puffed for a reason, so you will most likely puff it more.

Like I said, sell the good one, and you can send me the bad one and I can make a 3s 3000 pack out of it and then you can sell it too, or use it in something low draw. That way you can get some money back out of them.

You really need better packs, as your setup is most likely too potent for those 6000 packs.

Almost any setup is too potent for those older 6000 packs, IMO. :angel: I hear the newer ones are much better though.

Jason from maxamps told you that, huh...

Nope, Austin. He said they have a totally different source and that they are a big improvement in cell quality. While Jason and I are "less than best friends", Austin and I get along pretty well.

Austin had sent me a 25C 8k pack and it was significantly better than the previous "20C" packs. Who knows about the rest of them? I don't see myself putting any money into their lipos anytime soon, but I am hopeful that the new packs are as good as advertised for those who do purchase them.

Here is some info from the actual PM's:

"It is a different source that the new cells are coming from, yes. We actually will be upgrading all the cells to 30C over the next month or so. The 3000s will become 3250 30C cells(with no increase to price by the way). They will be followed by the 5000 cells, then the 4000 cells.

We tested them at 30 and 35C. They get about 2500mah at 35C constant and almost 3000mah at 30C constant with good temps. They are a winner. Its the best 3000 cell we have ever tested by far.

Lets see... at 35C it would last a little over a minute the way I figure it. I am thinking that there will not be many guys running it at even 30C constant for the 2 minute run time.

Bottom line is that voltage under load will be very high and it should not hit cut off under a short high amp load.

-Austin"

Love them or hate them, it's always nice to see improvement.

Alright linc, I may or may not run it, but I have had the official warning so thank you.

As I said I bought those packs because they are the same size as a standard 6 celler, and admittedly knew next to nothing about lipos when I got them last March. I've learned TONS since then and much of that info has come from you and other members here. I do have two EVO25's that work great, but they are also $120 a pop, I am eyeing the new Hyperion Sprint 4000 packs which are half the price, I will probably buy 4 of those so I can have 3 pairs. I do have someone in mind with a Slash who I can unload the good MA pack on, and I think this bad pack will be going out in a blaze of non-glory.... charge it-short it-shoot it lol I may even get video..... Thanks much for the info.

I will refer any repairs in the future to you linc. I just hope people will avoid MA altogether and not have the buyers remorse- it really stings....

Nice that they will not increase the price... I wonder why?

Dude, don't shoot it! I can make you a pack, or I will give you something for it if you send it to me. If you do shoot it you may as well shoot a tree. Nothing will happen. Over charging will make a bunch of smoke, thats it.

Not as fun as you may think.

Way to steal my thunder- Doh!

I'll be pming you linc, something is better than nothing for sure.

Ok, so a member here sent me a few packs and I thought one would be interesting to disect and show my wonderful viewers what it looks like.

This is a maxamps 6000 2s lipo. It is a 2s2p configuration of 4 3000mah cells.

Note the non-rectangular shape, this is due to puffing of at least one of the paralleled cells. I will disect it and take some more pics as I go.

http://i206.photobucket.com/albums/b...p/DSCF2968.jpg
http://i206.photobucket.com/albums/b...p/DSCF2969.jpg
http://i206.photobucket.com/albums/b...p/DSCF2970.jpg

I still can't believe MA or any other mfr would parallel cells like that. I know there are a few others, but the only truly safe way to work with that config is to charge it as a 4S and run it as 2S, but the balance tap is 2S....stupid!

Linc you should make a mattress out of all the puffy cells and make certain people sleep on said mattress- I'd pay to see it....

Took the shrink off.

Note that the 1st cell is very puffed, and the 2nd cell is slightly puffed. Both cells are very near 0v, so they are gone. A good rule of thumb is that if a cell is puffed it is done and needs to be disposed off. If a cell is not puffed and below 3v it may be able to be recharged. I have a technique for doing that. Also if the foil covering is torn at all the cell is done and needs to be disposed of.

On this pack the 3rd and 4th cell appear to be fine, they are a bit deformed by the puffed cell pushing on them, but should be fine. I still completely disassemble the pack and indivdually test the good cells before I make them into another pack.

I have found that maxmaps does not do the best job matching their cells. So in a paralleled stiuation you may have one cell that is stronger than the other. Now the badly puffed cell in this pack is likely a weaker cell, and it was asked to discharge a bit more than it could, and thus puffed. I have seen this alot with the 3000mah cells, as they are 15c cells at best, and even a 10th scale 2wd can draw more than they can put put out.

http://i206.photobucket.com/albums/b...p/DSCF2972.jpg
http://i206.photobucket.com/albums/b...p/DSCF2973.jpg

Only prob with your method is that the balancer wire hookup would not work with the cells paralled. Now you could have 2 completely seperate packs (1p config) that had some sort of plug on the output wires to parallel them together, and then shrink the 2 packs together to have 1 larger pack. Then seperate the output wires and wire it as a 4s pack when charging. The way the cells are assembled is that 2 cells have the pos tabs attached together, and the neg tabs attached together, basically making one larger "cell". Then those larger "cells" are assembled in series for the desired voltage. So unless you seperate the cell pairs there is no way to charge them seperately.

I have run 2s packs in parallel before, and then charge them as a 4s pack with a charge adapter, it is the best way to gaurantee that the cells are all charged properly. How ever if the cells are not all matched at the factory, you may never get them to work together perfectly. The only real way to do it would be to disassemble a 4s pack and make 2 2s packs and then wire them in parallel via the output leads.

This is all a waste of time IMO, as you can get good cells up to 6000mah (enerland) and if you want more runtime just swap out batteries, keeps the weight low and that is always desired.