Battery config plans

Hey there!
My plan is to build a 12s4p p42a pack.
Im going to use 0.15mm thick nickel (link for reference: 1 meter nickel battery soldering strip 26.2mm*0.15mm - for 21700 - Battery solder strip - Accupackaccessoires - Battery accessories | NKON)

Im going to connect the P packs in series with two pieces of 10AWG wire.

Will this be sufficient for the high current?

I’ll attach pictures of the layout, don’t judge my drawing skills


If there is space for improvements please let me know

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I’m not sure about over seas, but last time I paid that little for nickel strip, it was fake as a $3 bill. Other than that, I see no issues in the diagrams.

What kind of spot welder are you using?

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2 12awg connections is more than enough. 10awg is too bulky.

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I’m not sure, I have a friend who has one and he made a few ebike batteries with it, only thing he said is that he had some struggles with 0.20 thick nickel and I should use 0.15

Is it safe to solder the cable onto the nickel after it has been welded to the cells?

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Pre glob on the nickel where the series connections will be. Spot weld the groups. Then go back and apply the series connections. Either way you’re putting heat to a cell. But with this way, you don’t have to put as much heat as you would with soldering everything after you weld.

Take a small piece of the nickel, put some scratches on it. Enough to expose the inner metal. Take a glass of water, add salt (I usually put 1-2 tsp). Put scratched nickel in glass and wait a few days. If you see any changes, it’s not 100% nickel.

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I’ve redone a 10s3p pack that only used nickel strips (except for main pos and neg output) into a 10s4p pack purely by soldering to the existing nickel strips. Didn’t have any issues with heat or the cells heating up while connecting everything together.

Can’t say much on the long term stability of that battery since I fried the BMS and ended up unbalancing all the cells again. I was fed up with it and haven’t touched it since as it had already taken weeks to balance all the cells previously. (no smart chargers or monitors so had to discharge with led based loads and then charge two groups at a time with a basic charger)

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… Multimeter or voltmeter, whichever you want to call it. 1s charge board. Live monitoring. Go fourth my son and balance them lol.

Have you seen said built batteries? Are there pictures/video of said built batteries being built? How are said built batteries holding up to the abuse PEVs can deliver? Find out what welder he’s using. These are all important questions you SHOULD be asking. Remember, you potentially have a bomb underneath you if something goes wrong.

If you haven’t @least skimmed through it, check this thread out.

That is because the welder in insufficient and likely junk.

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Don’t judge so quick. There’s always the possibility that the power source he uses isn’t strong enough.

But I concur lol

The cells are of questionable quality and aren’t really worth it currently. The battery wouldn’t last longer than 9 months at best :person_shrugging: I killed a battery with the same cell quality in just 6 months of daily use in 2021. The cells just didn’t have the capacity anymore.

Voltmeters are devices made only to measure voltage while multi-meters can do that and much more. There are also stand alone ammeters but no one seems to even remember them ever existing these days :thinking:

If I ever get into making my own batteries I might use the cells as practice for spot welding and put them together for a short lifespan battery. Since that is the one thing related to battery construction that I don’t already know how to do.

As it is now it takes up more space than needed due to all the extra padding and insulation layers I had to add to ensure that vibrations couldn’t create any shorts within the pack. So many layers of masking tape and fishpaper or whatever that green paper is called. Not worth it for even just a temp battery unless I put it together with new nickel strips

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I agree.
I use mine almost every day though.

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I have one of those clamp meters that is super handy when i need it, but i don’t need it often

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You might be right, it’s Chinese I belive. Cost a few hounder bucks. Unfortunately I don’t have other options and I’m already way way over the budget so it will have to do.

I was wrong, it a cheap aliexpress one for like 50 bucks. I get it today, I’ll post some specs and pics later

I’ve read the forum, but I’ll definitely do some practice on shitty cells.
I’ve never seen the packs themselves, but it’s working. My friend also repairs laptop batteries and such with the same welder. I know thats a different story but still, I have high hopes

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So this that’s that

I’ve asked around in local esk8 groups and friends but noone had a usable spot welder unfortunately so I’m stuck with this one

If you plan on building more than one battery, buy a reliable spot welder. Maletrics, kboss are my two favorites. As well as multiple forum member’s favorites. Maletrics will run you around $140 I believe. KBoss I’m not exactly sure on price currently but you’d have to find them pre-owned. Can’t recall if the they still produce them or not.