Soldering batteries with nickel tape

[athletic91]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=221233236763

I have tried to solder 26650 cells together using normal wires and solder but the solder just won't stick onto the cell

. Can i join batteries together using the nickel strip with a NORMAL soldering iron? Could one use the tip of the soldering iron to "poke" the nickel strip onto the cells?

 

[dnmun]

you should use a spot welder.

 

[ecross]

-please use for low current usage better spot welder

-for high current please use pro solder stuff and special solder for aluminium

-for how much charge-discharge currents?

 

[GSW999]

Who's gonna go out and spend 1000 bucks on a spot welder to make their own battery????

With soldering you have to get the actual item very hot before the solder will take to it , doesn't matter how hot the solder is its the thing you want to connect to that really maters.

I tin the wire Im using . ( or I use triple solar busbar ( good stuff , the thicker strip for the ends of the panels ) , and then I carefully feed the solder underneath the iron tip and it will be "taken" by the surface if it is hot enough , how powerfu is your iron , mine is 60w

Disclaimer I'M NO EXPERT!!!

peace and goodwill

 

[ecross]

.

 

[999zip999]

I would buy the cells in spot welded parelle strips. Then you can series them up with a 80 watt or bigger iron.

 

[dmwahl]

Aren't you concerned about damaging the cells by soldering? I'm with dnmun, buy or build a spot welder. That said, if you insist on soldering them together be sure to use enough flux. Insufficient flux is often the cause of poor solderability.

 

[fechter]

Soldering directly to a cell will always damage it slightly but if you do it well, you can minimize the damage. I've made lots of packs by soldering to the cells with good results. I've also destroyed perfectly good new cells. One of the keys is to minimize the heating time, which means you need quite a bit of heat to get it up to flowing temperature quickly. If your iron is not big enough, it will take way to long to get it hot. Metal surface has to be freshly cleaned (Scotchbrite, sand paper, wire brush, ect.).

I always 'tin' a spot on the end of the cell before attempting a wire connection. Once a spot is tinned, you let it cool down, then come back and reflow the connection with the wire in place. If you can't get a spot tinned on the end, you won't be able to make a connection.

Not all cells are solderable with normal solder. Most are. The A123 cells I used had a nickel disc spot welded to the end which soldered easily. Bare A123 cells I think are aluminum, which I don't think you can solder adequately even with special solder.

Some cells have stainless steel cans. Stainless can be soldered, but you need special flux and it's not so easy.

 

[dnmun]

but the i thought that nickel tape is for spot welding as i replied initially. you can buy the spot welders on ebay too for $X dollars and then sell it to someone here doing a battery build for $X(-rent) and then they could build a battery and sell it to another person for $X(-2xrent) and so on. and just spot weld to the can if you do wanna solder somewhere, and do it to the anode. there is physical separation between the electrolyte and the nipple on the anode, with the pop top underneath.

 

[fechter]

The spot welder is the industry standard way to connect batteries. I don't think anybody will argue that. Results with the cheap eBay spot welders are mixed. What might be handy is if somebody had a service to either weld up sub packs or place individual nickel tabs on the ends of cells. Once you have the nickel tape spot welded on, it's very easy to solder the tape without cooking the cells.

Back when I first got my used A123s, I looked all over for somebody who could spot weld them but nothing cost effective ever showed up. I later figured out mine had nickel tabs on both ends, so soldering was pretty easy. So far, I'm pretty sure soldering them did not cause any significant problems.

 

[Hillhater]

For those of you planning to build packs by soldering or welding cylindrical cells ( 18650 is the most common) you need to be very sure of the EXACT type of cell you are using ( especially if they are either unbranded Ebay bargains, salvaged power tool, or laptop, etc cells).
Many of these cells now have various forms of "protection" built in ( or rather "on" to the ends) , such that what you think is the cell base or top, may well be a false contact, hiding some delicate components that may not take well to high temperatures or welding currents.
EG.. this is an example..

more detail here ..http://www.lygte-info.dk/info/battery%20protection%20UK.html
These systems are not always easily identified without stripping the cell covering, so just be sure before yo committ to a unknown cell pack.

 

[Matt Gruber]

UPDATE:
I now use JB Weld for pack repair, soldering not needed!
Previous remark:
i agree with dmwahl; FLUX , applied with a brush is essential. Lots of good ideas from other guys too.
making my 1st pack now.
Konion limn from used makita packs.
They have a thermal fuse under the + terminal. The fuse makes them FIRE PROOF when shorted! Perfect for guys like me that put safety FIRST.
BUT if they get hot soldering the built in thermal fuse will blow. then 0 volts available even with a good charge. I found that out when i skipped a step that i won't skip again ever.
Quiz:
What was the step? It was not mentioned so far.
This may be my 1st pack, but i have decades of electrical experience.

 

[2007blueprius]

when I first started to look into ebikes, and lithium chemistry, I first came across the ebay market, some of the manufacturers as I remember offered theyr cells with tabs prewelded in various configurations for something like 1c per cell, that would be a first thing to consider before taking on such a build, one can mock up the suposed pack and order cells with build in mind.
now if you allready past this step, or working with used cells, recycled laptop cells etc, best bet I think would be to find a local battery shop.
I explored that option too, and found couple different shops in my area, however at that time lithium was not something they were using, for the most part their bussiness was rebuilding powertool packs, mostly nimh chemistry, they were selling the small 8ah lead acid, all sorts of button cells and regular batteries etc.
however they did have a spotwelder, and all the supplies in stock, tape, shrinkwrap etc, and they were willing to build any pack in any configuration for labour and material costs, regardless of chemistry bring your own cells.
I never took on such a build but if i were to spend any significant amount on lithium cells, I would deffinatelly give them this job, I like to do as much myself, but when somebody else can do it better, even at a cost, which would probably be less than it would cost me to do it anyway, I would definately farm the job out.
now I live in michigan, if there is no such shop in your area, I'm sure one could ship the cells and a drawing to these guys and get it done but it defies the point, I know from experience it's not easy nor cheap to ship batteries, however I am pretty sure there is a battery shop in just about any major metropolitan area.