What Metal are the + and - terminals made out of on 18650 or 21700 cells?

[YoshiMoshi]

What Metal are the + and - terminals made out of on 18650 or 21700 cells?
I'm looking at spot welder ratings. Some have nickel to aluminum, nickel to nickel. Some have copper to copper, copper to aluminum, copper to stainless stell.

Essentially if I have nickel as my strip material to connect the batteries, I am welding to the plus and minus terminals of cylindrical cells, what type of metal are these terminals made out of? I assume steal as it's a hard silver colored material? Is it stainless steel?

Thank you!

 

[amberwolf]

Depends on the specific cell; some of the threads here about specific cells, and some of the cell-testing threads, have info about those for those cells. More general info is probably in the various interconnect and spotwelding threads.

lygte-info.dk might also have that info with their cell tests (I don't think I ever looked to see when I was checking out test results).

Some cells are steel of various types (most of the cans seem to be? but the other end can be different), some are nickel plated, some are aluminum, there are even cells with gold plated caps.

Then there are the recycled rewrapped cells that may have caps to cover the damage on them from being ripped out of scrapped packs, and those caps could be made of anything....

 

[BlueSwordM]

Most cylindrical cell cans are made of variants of stainless steel, with some cans made of aluminium.

Edit: Nickel plated steel, my bad.

 

[docw009]

Whatever wleder you get, you don't have to buy cells you can't work with, Go with a reputable seller like 18650batterystore or imrbattery and look at the data sheets for the cells they offer,










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[amberwolf]

Or buy a

Whatever wleder you get, you don't have to buy cells you can't work with, Go with a reputable seller like 18650batterystore or imrbattery and look at the data sheets for the cells they offer

Or buy a recovered ex-EV battery module, and keep the cells in groups as much as possible for the shape you need them to fit in, and just add new interconnects to the existing ones. Like these, among many other examples:

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[BatteryMooch]

Most cylindrical cell cans are made of variants of stainless steel, with some cans made of aluminium.

@YoshiMoshi, It’s my understanding that it’s just the smaller primary (non-rechargeable) li-metal cells that use stainless steel for the case. The cans for the typical round cells we use are nickel-plated steel. There are some aluminum cans out there for the larger cells though.