10s 4p lithium Ion battery

Btw you cannot solder and then spotweld, I read it somewhere on here the other day but I’m not sure which thread it’s in

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i ment spot weld and then solder them in series so they can be flat.

yea, if you solder then spotweld the solder you’ll have a nice sized pool of molten solder explode everywhere

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ok do you have any way to make it as flat as possible.

I Think i have this whole thing figured out on the battery just don’t know what spot welder to get if anyone knows that would help a lot thank you for all the help. I found this diagram and am gonna use it.

I also found these batteries and im not gonna use them just wanna see what you guys think. https://www.ebay.com/itm/50PCS-6000mAh-Li-ion-18650-3-7V-Rechargeable-Battery-For-Flashlight-US-Stock/131982325534?_trksid=p2054502.c100227.m3827&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908103841%26meid%3Dc4e18d3eb64249f7a5616606f8b0f2a6%26pid%3D100227%26rk%3D1%26rkt%3D5%26sd%3D131982325534&siteId=0&AdChoicePreference=true&rmvSB=true#rwid

These 30a spot welders are a joke. Don’t waste your money on it. 30a is not enough power for welding batteries and this welder has a habit of tripping the circuit breaker as well. I know this first hand. You need at least a 60a spot welder with multiple pulse.


Thanks i noticed that after i posted im looking for a better one right now thank you.

Those batteries are no good and probably fakes. Have a look at sunko spot welders they are meant to be pretty decent

Thats why im getting the samsung 30Q one and ill take a look at the spot welder thanks.

Build my spot welder, save your money…

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what do i do with the part of the cells that are suppose to directly connect in the diagram. The connections in the center of the two cells how does that work.

That diagram is incomplete or simply wrong. You need nickel strips on the positive and negative ends of each parallel group

How did you test the welds to make sure they won’t pop loose later?

That diagram is a zigzag pattern, with the output wires on opposite ends. This leads to long leads and that can lead to voltage spikes. Instead, for my battery pack, I did all of the connections like the outside ones, and as a result my pack ended up “U” shaped, with the output wires on the same end. As long as you insulate between the cells in the middle, it’s a more compact setup in my opinion.

Well, I have a real world test where I’ve been using my original pack I made up for a little under a year and it’s perfectly fine still… so…

do you have a diagram I think i know what your talking about i just want to be sure of it.

I also found this one from longhairyboy does this have the same problem as the first. And how many layers of the nickel strips should i have. Thanks

I also read that sunko spot welders wont work with the typical american house breaker is this true and if so what is alternative.

What I did and I recommend especially for people building their first battery is to do a test weld on a spare battery and then try to pull the strip off with pliers. A used alkaline battery can be used for the test.

I’ve done plenty of those tests… Have you bit seen any of my videos? :rofl::joy:

I haven’t seen them. Just thought I should mention it for the newbies who are jumping into making their own batteries.

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