no solder battery help

lxgoldsmith

lxgoldsmith

10 W
Joined
Apr 9, 2014
Messages
94
Location
Maryland
I have bare copper wire and a ton of 18650 cells, probably more batteries coming in for me to tear open.

I'm still trying to bulk charge the cells, and I tore off most of the tabs, so please don't lecture me on how I should have left them on. I know

So far, I have these options:

1. keep trying to solder with a 30W iron, buy more flux and solder
2. buy a new, higher wattage soldering iron plus flux and solder
3. buy conductive tape for a soldered wire substitute
4. any other no-solder method

Any suggestions?
 
for a large qty of cheap/free cells a few fried test cells can be acceptable, if the expense is low, and it goes fast.
so as the cheapest method i can think of, get 2 half inch steel rods from the hardware store and set up a stand to hold one in front of a propane torch. NEVER torch a cell directly! Heat 1 rod and use it to solder while #2 is heating. Switch rods as they cool off. May want to grind the end of the rod to a nicer shape. Be sure to get some proper flux
 
cwah said:
This method is nice and clean:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=57810
Click to expand...

I really like the setup, and it's doable with my materials except for the 18650 spacer block. I can't find anything like that for cheap.

The immediate problem is connecting the positive terminals for bulk charging. The negative terminals are connected by aluminum foil in the base of a box. The top ends don't connect so easily to another set of foil. Soldering has failed completely. It didn't stick to the wire for 1/2 of them.

Th negative terminals can wait until after a bleed down test.

After this, it's smooth sailing. I might have access to a 24V electric go-kart for testing.
 
Found my dad's 140w solder gun and my teacher gave me some solder. I also found some duck tape. I used that and some foil to put some cells in parallel. we'll see whether that works too.

How can I tell if I damaged a cell with too much heat?
 
lxgoldsmith said:
Found my dad's 140w solder gun and my teacher gave me some solder. I also found some duck tape. I used that and some foil to put some cells in parallel. we'll see whether that works too.

How can I tell if I damaged a cell with too much heat?
Click to expand...


It's easy to know through visual methods. If you see solder on the cell, it's damaged.

The extent it's damaged you will find out later when cycling the pack. The damage could range from very minimal to certain impending cell failure.
 
lxgoldsmith said:
cwah said:
This method is nice and clean:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=57810
Click to expand...

I really like the setup, and it's doable with my materials except for the 18650 spacer block. I can't find anything like that for cheap.

The immediate problem is connecting the positive terminals for bulk charging. The negative terminals are connected by aluminum foil in the base of a box. The top ends don't connect so easily to another set of foil. Soldering has failed completely. It didn't stick to the wire for 1/2 of them.

Th negative terminals can wait until after a bleed down test.

After this, it's smooth sailing. I might have access to a 24V electric go-kart for testing.
Click to expand...

I got the spacers that I used to build the pack in the reference above from this ebay seller :http://www.ebay.com/itm/321114252941?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649. They sell them in different sizes for, I thought, a pretty reasonable price.
 
lxgoldsmith said:
So the 30-40 cells I soldered are now trash?
Click to expand...


Every soldered cell is trash if you require undamaged cells.

If you can tolerate potential random cell failures etc, then they aren't trash to you.

The scary part to me is how many people start from totally unknown condition used laptop battery 188650's (which should be trashed) and then add solder (which should make them double-trash), and then leave it in there homes at night.

Yes, once upon a time I did similar things before I knew better. Fortunately, you can choose to learn from my hard lessons to spare yourself from learning it the hard way as well (not that there is anything wrong with hard lessons, they are critical for life fulfillment).
 
I'm just trying to test the batteries here, and a foil box doesn't work on the positive terminals, since they're flat and slightly recessed behind the plastic wrapping.

Has anyone here had batteries plus do spot welding? If so, what price did they charge you?
 
they only will spot weld to battery cells you buy from them. you kinda lost all chances when you stripped the tabs off of the cans.

it really is not worth the effort to try to make laptop batteries work since they spend their entire life sitting on a charger at 4.2V so there is nothing left to use when they get trashed. the dank angle guy who has a thread about using them never even tests capacity but if he did you would see there is not nearly enuff storage capacity left in them to make the effort worthwhile.

he strung another guy along for months now and all that guy's efforts are also just a waste of time now because he has no idea of their capacity to store charge.

most people who test them for capacity put them into a clamp that contacts each end so they can discharge the can into a dummy load and measure the total charge discharged from the full charge 4.2V to totally discharged at 2.7V. if you did that to several of the cans you have there you would understand what he means by trashed.
 
I actually disagree here. In my efforts to charge my cells, I've noticed quite a bit of residual charge, maybe even 80%. Half of the packs were not even balanced correctly by the pcm, so they ended up "dead" with one cell bad. Multiple times after removing tabs, there was one cell that dropped to 0V or similar.
 
but you have never actually measured the storage capacity so you don't know. you only know there is some kinda voltage and that tells you nothing about the storage capacity.

maybe if you did test a few it would be more clear about how much capacity they still have at the end.

better yet, measure capacity on one of the cans and then solder a lead to each end and then retest capacity to see if you can measure the effect of soldering to it.
 
I can see hat amperage I'm putting into it and how long it takes at each state of charge as well as the application of the ah measure on my imax b6. Discharging a few cells has proven similar capacity results. I don't do unnecessary work, so if it wasn't worth taking apart the packs, I would know beforehand. Now I know I made a mistake by also removing the tabs.
 
You are aware that seeing voltage on the cell has nothing to do with the useful capacity or performance of the cell right?

Laptop batteries sit in high-temperature environments at high SOC's until the cells age to the point the pack get's replaced because some cell kicks the bucket first (with the others not far behind him).

If you are seeking the 'right way' to make a pack from discarded laptop cells, there isn't one. If you are merely looking for entertaining yourself and learning a lot (some easy lessons, some hard lessons) while playing with cells, then you are on the right path.
 
dnmun said:
it really is not worth the effort to try to make laptop batteries work since they spend their entire life sitting on a charger at 4.2V so there is nothing left to use when they get trashed. the dank angle guy who has a thread about using them never even tests capacity but if he did you would see there is not nearly enuff storage capacity left in them to make the effort worthwhile.

he strung another guy along for months now and all that guy's efforts are also just a waste of time now because he has no idea of their capacity to store charge..
Click to expand...

are you referring to "Dark Angel" ??
If so , i would have to ask what you are talking about !.. he has probably done more testing of capacity measurement , cell life, and test methods,..than most people who contribute here.
http://endless-sphere.com/forums/viewtopic.php?f=14&t=54202
http://endless-sphere.com/forums/viewtopic.php?f=14&t=53017
Also much of his testing has been specifically focused on recycled laptop cells, with practical "on bike" testing of the resulting packs.
You know this , because you often contribute (mostly negatively ) on his threads,........ so i dont get where you can say ....
he .." never even tests capacity ".. ???

LXgoldsmith,.. there is a lot of useful information on this site from many experienced posters,..but not all of it is always 100% accurate, and some folk have their own agenda to promote it seems !
The best thing to do is to search out threads on similar topics to your issue ( IE testing, assembling packs from used laptop cells , etc ) , then read as much as possible and form your own opinion based on the range of information available.

There are several threads on how to assemble 18650 cells without soldering, and many threads on packs successfully built with soldered connections.
 
I don't think I said that capacity or overall quality had anything to do with initial voltage. Resistance is found by using the amperage and change in voltage under load. Different states of charge hold different amounts of amperage. There's more capacity above 3.6V than below.

I'm trying to do the rest of the testing. Different charging methods have resulted in more heat generation in certain areas, ie rearranging a pack caused the right side to get hot in multiple cases.

I made an offer of $20 for 50 battery holders that was accepted.
 
I just got them in the mail. I put a cell in and it doesn't even make contact on the positive end because the wire is larger than the contact point. That doesn't matter though because it has holes on the top and bottom so I can put in my own wire (I think 14-16 gauge). It'll work out well for stringing together and taking apart to put a fresh batch of untested cells in.
 
"You know this , because you often contribute (mostly negatively ) on his threads,........ so i dont get where you can say ....
he .." never even tests capacity ".. ???"

i never post on that guys thread except for when he starting insulting ebeach and then had the gall to insult me like he is some kinda charming angle. the guy is totally bogus. his capacity measurements are nothing but mental fabrications. i never saw any case where he actually charged a cell to full charge and then discharged it to full discharged, into a dummy load and measured the capacity. never.
 
Can we pls not go so OT as to start personally bashing other users that have not even posted on this thread? I'd rather not respond to such remarks when they are made, and could you pls do similar?
 
i was quoting your statement on this thread about how i post up on his thread. there is nothing personal about the fact that he has no basis for his construction of these charging profiles as some indication of the capacity of the cell. you made a statement to the effect that he was proving something which was not the case. it was personal when he attacked ebeach for making the observation that he was making statements which were incorrect.
 
Thanks.

I just got some batteries that are lipo. Would they use wires instead of welding? That would make my life easier.
 
You must log in or register to reply here.

Similar threads

whatever
Mosfet hole cleaning solder out
Replies
5
Views
464
red
red
S
  • Question
Ebike Battery Pack Repair Help
Replies
9
Views
1,175
docw009
docw009
Jackal21
Help in identifying voltage drop/overheating reason
Replies
12
Views
740
Jackal21
Jackal21
NinjaKitten
Some Questions About 18650 Cells and Designing A Battery
Replies
4
Views
1,914
Diggs
D
c111jp
Samsung 50E vs LG M48 vs "Tesla" (help me choose new battery pack)
2
Replies
26
Views
3,155
c111jp
c111jp
Back
Top