Current Flow Question

Esk8 Electronics Guides, Support, & General Questions
#1

I have a question when wiring Molicel P42A batteries in parallel. They have a peak of 45A. A nickel strip can probably do 7A depending on the width and thickness. My question is if I use one layer of nickel strip then, on top of that, use copper wires, would the current even flow through the nickel strip? I mean, I’m sure it will flow through the nickel strips but the majority of the flow should be in the copper wire, right?

It should, in theory, go through the nickel strips and then travel on the copper wires because it has 1/4 the resistance compared to nickel strips.

#2

Have you looked in the battery builders thread lately? Because no pack in there is using 7mm wide nickel ladder. They’re all using ~30mm wide 0.2mm thick nickel.

You should read that thread before building a battery.

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#3

It’s 10mm x .1mm. My spot welder can probably do .15mm but I already have the .1mm here but I also have copper sheets.

I tried to copper nickel sandwich but it couldn’t do it.

I figured I can punch holes on the copper sheets and solder on the top of the spot welded nickel strips.

My question is if the current would ignore the nickel and flow through the copper since the copper is less resistant than the nickel.

Thank you.

#4

that is mighty thin

#5

Of course it’ll have to flow through the nickel a bit at first but then the current will go though nickel and copper based on the resistance and ohms law…and largely through the copper

#6

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#7

Quick question. How many stacks of 10mm x .1mm nickel strips would I need for P42A? I did the math and I would need 5 stacks?

#8

0 stacks, that doesn’t hold up well in a high vibration environment. Also, 5 stacks is basically impossible. Get wider, thicker nickel

1 Like
#10

Do you have a link for them?

I got this. Amazon.com

I already have them glued up.
image

Horrible paint drawing but you get the point. LOL.

#11

3 cells probably only needs about 50mm wide. Also get something thicker in the .15 range. Once you receive it, you should do a rust test to confirm it’s pure nickel

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#12

I’m guessing that link is fine for me to buy? I’ll buy 1 pack for now and test if it’s genuine but if you have a certified link already, send it my way. Thank you.

#13

That nickel is not thick enough.

1 Like
#15

Quick question. The drawing I made above. It’s P42A. Those cells can do 45A. I’ll be using 50mm * .1mm wide nickel sheets. Do I just need 1 layer then? I did the math. The sheet can handle 48A.

I used the data from a 7mm * .1mm on the esk8 ampacity chart to get 48A.

50mm * .1mm = 5 cross section.
7mm * .1mm = .7 cross section = 6.61A

5 / .7 = 7.14 * 6.61A = 48A.

So 1 layer should be enough right? I was going to do 2 layers of the sheet.

#16

You should ask in the battery builders thread. But I would not double up the sheet.