Help with 6S 10Ah Lipos with dead cell.

[00Tj]

Hey everyone.

I got 2 of these packs today (second hand with a bike I bought) :



So I threw them on my charger and this is what I got..





So my question is.. Can these pack's be saved? And if not... Doe's anyone want to buy them?

Also, the guy who I bought them off said he would help me replace them if they couldn't be revived.

Thanks guys!

 

[dnmun]

cut the shrink wrap off first. expose both batteries and take pictures from the side so we can see if they puffed up. measure the voltage directly on the cell tabs with your voltmeter. do not measure from the JST plug. measure directly from the tabs.

 

[00Tj]

Ok, I'll do that now. Cheers.

 

[dnmun]

some packs will come apart by unsoldering the tabs but now they are often made by using the roll crimper on the tabs and they are not soldered which makes repair very difficult. we will know when we can see your tabs. if the sense wire has disconnected from the tab then that would account for the inaccurate reading and it could be repaired by soldering the sense wire back onto the tab.

after you can assemble the pack into one pack with hardboard endplates and put it back into compression.

 

[00Tj]

This is where i am so far.... Looks like damage..

 

[dnmun]

yep, shorted when the electrodes got crushed i bet. but you confirmed the measurement?

take the plastic tape off of the top over the tabs and take a picture of how they are connected serially. you may be able to salvage a lot of this but it looks like more than two are crushed.

 

[Ykick]

At minimum that's gonna need some surgery.

Did anything strike/hit/bump the pack?

I've had cells rupture similar to this from the inside-out. Here's a thread I posted a pic of ruptured cell a couple years ago:

http://endless-sphere.com/forums/viewtopic.php?f=35&t=49900&hilit

 

[00Tj]

Solder it is..

 

[dnmun]

ok so they are using 2 of the 5Ah pouches soldered together in parallel to make 10Ah. so each of those solder blobs has two positive and two negative electrodes so unsolder down the middle to separate cells.

i use two soldering irons since it takes a lotta heat and i lay them on their side over the edge of the table and just allow the solder to melt and then i sweep it off of the tabs with the soldering irons so it falls down onto the floor, into a plastic dishwashing tub lined with aluminum foil to catch the solder.

 

[00Tj]

I only got them today with a bike. So I don't know if they have taken a hit?

Also, these are 2 separate packs. The two photo's are of the 2 separate packs.

So one of them looks like only 1 single cell is damaged and the second one look's like 1-2 of the cell's are damaged.

 

[00Tj]

i use two soldering irons since it takes a lotta heat and i lay them on their side over the edge of the table and just allow the solder to melt and then i sweep it off of the tabs with the soldering irons so it falls down onto the floor, into a plastic dishwashing tub lined with aluminum foil to catch the solder.

Ok, It is midnight here so I'll do that tomorrow morning. I just wanted to know if any of them were salvageable.

Would I be better off just selling these and getting the guy who I bought it all off to give me the difference to buy new one's?
Also, what are these thing's worth per pouch? And where could I get just single pouches?

Thanks for all your answer's everyone! I really appreciate it!

 

[Ypedal]

Seriously, i would junk both those packs...

Some things are worth fixing, but some are not... and this is a NOT imo.

When you buy brand new packs and they arrive with a bad cell, you know the other cells are usually in good / new condition and will play nice together once the bad cells are removed but on used packs, of unknown quality, with some use, and physical damage showing, it's just not worth it.

 

[00Tj]

He said they were balanced charged and all working ok only a couple of week's ago so maybe they were damaged in transit?? He said he was still getting around 35km's round trip each day with charge left.

And what about the one pack that is all around 3.70-3.74V? Aren't they ok?

 

[Ypedal]

i assum you run these in series for 12 cell .. 45v .. if so, finding matching cells to the rest of those will be a mess and a guess... is this all hooked up to a properly working BMS

 

[00Tj]

i assum you run these in series for 12 cell .. 45v .. if so, finding matching cells to the rest of those will be a mess and a guess... is this all hooked up to a properly working BMS

Yes they were run at 45V. I am pretty sure they don't have a BMS? Cant see one but there may be one on the bottom of the pack (but that is unlikely)

I was also wondering.. I have 2 of these 40V 4Ah Li-ion packs that are used for garden equipment. They are brand new and still in the box. I was wondering if I opened them up and took the cell's out (and maybe got another pack) could I do something with them to replace my original packs?

 

[Ykick]

Mixing & matching cells you should learn about IR (internal resistance) testing.

[youtube]usRE3gLFnOc[/youtube]

http://endless-sphere.com/forums/viewtopic.php?f=14&t=48739&hilit=

Solder reworking large tabs is not for small size irons. You don't need high wattage but you do need a BIG tip. Hammerhead tip is my favorite with 60W iron.

 

[00Tj]

Yes I know how to test internal resistance. And I am not talking about mixing and matching. I am talking about scrapping the two 22.4V packs and starting fresh with the Li-ion cell's in the 2 (possibly 3) garden packs.

 

[dnmun]

Yes I know how to test internal resistance. And I am not talking about mixing and matching. I am talking about scrapping the two 22.4V packs and starting fresh with the Li-ion cell's in the 2 (possibly 3) garden packs.

the tabs are only visble on the top side, you have to expose the bottom end too so you can unsolder them on that end as well.

you may end up with 10S or 9S out of these so to get to 15S from 9S you would need two 5Ah 6S 25C lipoly packs added to the end after you hack it up.

 

[izeman]

your question was a bit confusing as you're bringing up a new topic in this thread.
so you will dump the lipo and build a new battery from the two tool batteries? could work, depending on the cells used in this packs. normally those are 18650 cells. and there are different versions with different C-rates and different capacity. you CAN use them anyway - if they will fulfill your power needs: we will know after you identify the cells and tell us what power demands you have.

 

[00Tj]

Thanks, I was just bringing up the li-ion packs because someone said that it was not worth even trying to save the 2 original lipo packs.

I will let you know once I open the li-ion packs up on what cell's are in there.


Actually, I just want to ride asap!... Anyone got a 50V 10Ah lipo or Li-ion pack for sale??

 

[00Tj]

What about 2 of these?

I have a 1680W cyclone kit that was running 44.4V 10Ah. So 2 of these should work fine yeah?
Is 10C enough when you have 16Ah? That would technically peak at 160A?

Or even the 10Ah one's if the 16Ah's wont fit in my custom battery box. Will have to measure it in the morning!

 

[dnmun]

if you have that kinda money to throw them away. count on only about 35-40A max discharge from those 10C packs.

 

[izeman]

What about 2 of these?

there is a whole thread about those batteries on E-S. started reading it, but i'm not sure what the outcome was.

 

[00Tj]

if you have that kinda money to throw them away. count on only about 35-40A max discharge from those 10C packs.

But isn't 10C at 16000mAh 10x16=160A? I thought that was the math?

And I will not be buying them! As I have said a couple of times the person who I bought the bike/batteries off will be paying for new packs. I/He expected about $400 so 2x$143.46=$286.92 isn't so bad.

The question was, are the original lipo's worth salvaging/selling to recoup some cost's of the new packs.

 

[dnmun]

you cannot use the ones that are crushed. i asked for you to show a picture of the other end so we could see the tabs there too.

for the cells that shorted to 0V there is nothing to do but scrap them and several of the others which have been crushed should also be scrapped since they will likely short soon too.

so i figured you would end up with about 9S out of the 12 total you have. so you could make a 15S pack by adding two of the 6S 5Ah hobby king lipoly paralleled to 10Ah and in series with your current 9S to get to 15S and then use a 15S lipo BMS and bulk charger.