turnigy lipo rebuild

[jansevr]

over the course of owning and operating a few bikes in the past year and a half or so i have come across many dud cells. i know this isn't an uncommon thing.

some were nearly dead on arrival or died after a few cycles. other packs worked for a few months and then had one weak cell drop to the point were the pack was retired.

whether or not it was the best idea, i have kept most of the packs which i thought might be able to be salvaged at some point. although i still am not comfortable rebuilding these packs, maybe someone is? i would be willing to send these packs and pay someone to salvage them if possible. maybe it is not worth it to do this, or not safe? Is there anyone that has any experience with rebuilding turnigy packs?

 

[NeilP]

Well you have not put your location in the profile that appears in your posts so it would depend on how far you had to post them. The cost of the postage and repair of them would cost more than just buying new ones.

Just buy yourself a big soldering iron...200 Watt sort of size and try it yourself

 

[Ykick]

Location please?

I use 60w iron with hammerhead tip for brick surgery. Do it all the time and in fact I just buy 6S bricks and make whatever config I want. Not for faint of heart but not too hard either.

 

[dogman dan]

I wouldn't advise mailing any packs with suspect cells.

If you have a pack with a bad cell on the outer edge, it's really easy to make a 5s into a 4s. You do need a good strong soldering iron to move the big wire to another terminal.

 

[toaroa]

I have a few 5s with one dud cell (all at outer edge). I'd be interested in how you can make 4s out if them. Could somebody give a step-by-step? I.e., what other terminal? ... I assume this is some sort if bypass, but one wouldn't need a proper 4s protection circuit? Cheers. Brad

 

[Ypedal]

it's not ... easy.. but possible.

http://www.ypedal.com/Lipo/repair.htm

and.. yeah.. location.

 

[dogman dan]

Removing the outermost cell is pretty easy.

Remove all the shrink wrap.

Carefully peel away the bad outer cell from the bottom. Heat can help loosen the double side tape.

Using a short nosed wire snips, carefully cut the pcb to remove the last cell. This is the only tricky part. DO NOT let metal snips touch positve and negative sides of the pcb board at the same time. If you do, ZAP. Short snips cannot reach across the whole board and make the contact, long scissors or tin snips can. So if you use tin snips, only use the tips of them.

Now you have the cell seperated, but still attached by the last thin wire to the jst plug. Snip that wire at the base of the plug. If you have two thin wires attached to the removed cell, the second wire into the plug needs to be reattached to the main pack. The plug is now wired for 4s. You can replace with a 5 wire plug, or even snip away the corner of the plug so it now fits into a 4s socket.

At this time, unsolder the big wire, and reattach in the correct spot. It will either be the main + or the main - wire. Determine where to solder it on with a voltmeter.

Get some clear packing tape, and wrap up the pack as tight as possible, with multiple layers of tape to protect the cells. Any tape that doesn't stretch much will do.

 

[Ykick]

Couple users have donated their puffed, damaged Lipoly packs to me and I've stripped several (8-10) 6S bricks completely down to bare PCB. I mostly use 15S on my bikes and commonly do 2qty 6S and one 3S. Once my skills got up to speed, I just buy 6S and make my two 3S from one of those. Same batch, the cells are better matched too. Of course, it voids the warranty, LOL....

I wouldn't attempt this without the hammerhead tip. If the solder on tabs/pcb doesn't flow in 1-2 seconds you need a bigger tip not more wattage. Longer you leave the iron on the tabs the more likely heat will damage the pouch seal around the tab.

Cells are stuck together with double sided tape or adhesive. To separate, I use a credit card and some lighter fluid or alcohol to soften the goo and work the credit card between the cells. Allowing time for the goo to soften.

Most difficult part for me is lifting tabs from the PCB. I flow the solder then sling the brick throwing molten solder onto the floor or somewhere you don't mind solder landing. If the tab is still stuck down you should be able to work a small blade or pick tool under the tab after another quick flow from the iron.

Occasionally, I've had molten solder short across the cells but it usually just flashes and disolves on it's own. Goes to show how you should be wearing eye protection though. I used to use tape to help prevent solder shorts while working on bricks but 'learned 3-4V isn't too dramatic for a momentary adjacent solder short.

Not exactly easy but not exactly "brain surgery" either. I cannot stress enough to Google and source a Hammerhead tip. That is key IMO.

 

[Ypedal]

flinging solder is a BAD IDEA... very bad idea..... yeah i've done it, and even tried compressed air ( liquefy solder and blast with air pig... even worse idea than flinging it !!! )


my 0.02

 

[Ykick]

flinging solder is a BAD IDEA... very bad idea..... yeah i've done it, and even tried compressed air ( liquefy solder and blast with air pig... even worse idea than flinging it !!! )


my 0.02

It probably is. Wonder how an old vacuum cleaner might work instead? I've gotta couple laying around that still suck - gonna test that. Certainly less mess and thanks for the usual inspiration!

 

[ddk]

flinging solder is a BAD IDEA... very bad idea..... yeah i've done it, and even tried compressed air ( liquefy solder and blast with air pig... even worse idea than flinging it !!! )


my 0.02

It probably is. Wonder how an old vacuum cleaner might work instead? I've gotta couple laying around that still suck - gonna test that. Certainly less mess and thanks for the usual inspiration!

http://www.amazon.com/Parts-Express-Solder-Sucker-desoldering/dp/B0002KRAAG

 

[jansevr]

neil, you're right about mailing them, its not worth it. i only have a 40w iron now, so ill definitely need a different one.

ykick - why the hammerhead exactly?

ypedal i haven't had the time to watch all of your video but that should help explain most of it. i understand this isn't the most complicated thing to do but I'm sure you guys know how something like this can be nerve racking. haha like flinging solder and shorting batteries. if i do manage to cause a short while soldering while this generally just dissolve as well? or is this only when flinging?

and my last question is how much harder would it be to add a cell? for example: take 1 dead cell out of a 6s and add 1 good one from another battery. would the PCB need to be somehow modified?

thanks for all the help and the link to the solder sucker. I've heard of them but don't have one. Definitely seems more ideal than flinging :lol:

 

[sn0wchyld]

neil, you're right about mailing them, its not worth it. i only have a 40w iron now, so ill definitely need a different one.

ykick - why the hammerhead exactly?

ypedal i haven't had the time to watch all of your video but that should help explain most of it. i understand this isn't the most complicated thing to do but I'm sure you guys know how something like this can be nerve racking. haha like flinging solder and shorting batteries. if i do manage to cause a short while soldering while this generally just dissolve as well? or is this only when flinging?

and my last question is how much harder would it be to add a cell? for example: take 1 dead cell out of a 6s and add 1 good one from another battery. would the PCB need to be somehow modified?

thanks for all the help and the link to the solder sucker. I've heard of them but don't have one. Definitely seems more ideal than flinging :lol:

hamerhead is because it has a large mass, so when you touch it to the relatively cold solder on the pcb it can impart allot more heat in a short ammount of time. It also will have a much larger surface area in contact with the solder on the pcb, again, imparting more heat in a shorter amount of time. something bigger than 40w would still be a good idea though.

those suckers are good, but for the amount of solder you'll be trying to pull off the pcb you may want to buy two, and pull one apart (or just use a funnel if you have one) and attach it to a vacume cleaner or something. use a bit of iron wool or something in the tube of the vacume if you dont want the bits of solder going in the bag (though they should be cold/hard to not cause issues long before they get there)

 

[Ykick]

neil, you're right about mailing them, its not worth it. i only have a 40w iron now, so ill definitely need a different one.

ykick - why the hammerhead exactly?

ypedal i haven't had the time to watch all of your video but that should help explain most of it. i understand this isn't the most complicated thing to do but I'm sure you guys know how something like this can be nerve racking. haha like flinging solder and shorting batteries. if i do manage to cause a short while soldering while this generally just dissolve as well? or is this only when flinging?

and my last question is how much harder would it be to add a cell? for example: take 1 dead cell out of a 6s and add 1 good one from another battery. would the PCB need to be somehow modified?

thanks for all the help and the link to the solder sucker. I've heard of them but don't have one. Definitely seems more ideal than flinging :lol:

hamerhead is because it has a large mass, so when you touch it to the relatively cold solder on the pcb it can impart allot more heat in a short ammount of time. It also will have a much larger surface area in contact with the solder on the pcb, again, imparting more heat in a shorter amount of time. something bigger than 40w would still be a good idea though.

those suckers are good, but for the amount of solder you'll be trying to pull off the pcb you may want to buy two, and pull one apart (or just use a funnel if you have one) and attach it to a vacume cleaner or something. use a bit of iron wool or something in the tube of the vacume if you dont want the bits of solder going in the bag (though they should be cold/hard to not cause issues long before they get there)

Totally agree with everything in this reply post. Good info as usual.

DDK - thanks but that solder sucker won't make a dent in the amount of solder you must remove from Lipoly tabs. I tried with very similar before "flinging" solder on the floor or into a trash can. What I meant is that I've gotta old vac which I don't care if solder messes up and probably won't. Main ssue would be managing the hose as some sort of solder sucker but that shouldn't be a huge problem to resolve. Maybe reduce it to smaller, flexible hose? Gotta try it when I get back to NY.

As explained above, large mass tip delivers the heat quickly and efficiently. I've seen very high wattage irons unable to flow solder even after many seconds because they don't have enough mass. Some of those high wattage irons are intended for sustaining a run of solder on things like stained glass, etc.

Cell tab doesn't need high heat, merely enough heat to flow solder in a second or two. Best way to deliver that quick heat is the Hammerhead tip. 60W is enough and just about right in my experience. The places that sell 'em (not expensive) sell RC pack building supplies. We can probably assume those good folks have been down this road before.

 

[ddk]

...those suckers are good, but for the amount of solder you'll be trying to pull off the pcb you may want to buy two, and pull one apart (or just use a funnel if you have one) and attach it to a vacume cleaner or something. use a bit of iron wool or something in the tube of the vacume if you dont want the bits of solder going in the bag (though they should be cold/hard to not cause issues long before they get there)

Totally agree with everything in this reply post. Good info as usual.

DDK - thanks but that solder sucker won't make a dent in the amount of solder you must remove from Lipoly tabs. ...

that's interesting comment, since that solder sucker* is exactly what I use to remove the solder from the tabs on 3 each 5S Zippy cells I recently rebuilt.
Cell #4 went south on one of the batteries and killed the other batteries paralleled to it.
I removed cell #4 & #5 making 3 each 3S then removed the three good #5 cells and made a forth 3S.
The mechanical suckers work best for something like this, but they cost a wee bit more than ~$6


*It needs to be cleaned out after every other 'suck' however -lol-

 

[Ykick]

Hear ya man. Maybe it's bigger than the one I have or my tabs had more solder than yours but my experience is that it just wadded solder up inside, didn't get it all and needed far too much cleaning. And as you should know, everytime you don't get it all - makes it that much harder to get hot enough again because now there's less solder to "flow" the heat to the rest of the solder on and around the tab.

 

[ddk]

Hear ya man. Maybe it's bigger than the one I have or my tabs had more solder than yours but my experience is that it just wadded solder up inside, didn't get it all and needed far too much cleaning. And as you should know, everytime you don't get it all - makes it that much harder to get hot enough again because now there's less solder to "flow" the heat to the rest of the solder on and around the tab.

might be because I have almost 50 yrs experience with'm?
who knows... I just replaced my old one after 40yrs because the spring finally got too weak.

@op once you get tired of searching for a hammerhead tip, buy a Weller 80W with it's massive tip @ about $25 online.
Worth the money for (de)soldering massive things lol. If I'm not working around batteries or plastic crap I use butane torches for soldering...

 

[Ykick]

Ypedal's original repair thread:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=26219&p=379848&hilit=+Hammerhead#p379848

Link is still good:
http://www.cheapbatterypacks.com/product/60/Hammer-Head-Solder-Tip