The battery builders club

The welds look okay, but I’m much more concerned over the use of apparently 18650-sized (~18mm-OD) fishpaper rings on 2170 cells. It defeats the entire purpose of insulating the negative cell body around the positive electrode if the insulator isn’t actually large enough to cover it.

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ofc you would choose this particular video

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Got a source for them? I read that the 18xxxis okay

If you can’t pry them off they are good

But are you gonna use just one layer? I think is way undersized for the current you can push from these cells

I mean I’m only gonna pull 30A at most…it’s a single 5065 that’s got a really high hearing and is only used on flat ground

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Even so I would at least double or do a copper wire, 30 A is already way above what a single strip can handle. One hill that makes the 30 A stays for a while and it will get hot

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I’m seriously hurting for space, but I’ll double the nickel on it for sure then

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What’s the difference between eskate and ebike batteries? Ebikes seem to be able to get away with using cells with lower discharges or even used/salvage cells. Is it because of the motors, controllers, or both?

Both. Normal ebikes (not those super powerful eMTBs) often have a 20 or 30A controller. The motor only can do what the controller can. And the controller determines what kind of battery you need. In the case of a 20A controller you can use 2 or 3p of a fairly low discharge (but instead high capacity, maybe) cell. Even if you need more discharge there is often enough space to just use more cells in parallel instead of using more expensive higher discharge cells.

Edit: you will see more than 2 or 3p in practice though. Something like 13s4/5p or 14s4/5p is common. ~12Ah is a typical ebike battery.

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Vibrations. Skates have much higher levels of vibration

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Need some advice regarding p group configuration for nickel strips, should I cut mini pieces and solder them like this

Or will this be ok? Cause this way is waaay less work lol

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Depends on your current draw, either way you should not be soldering strips on top of other one, kinda defeats the purpose of welding them. I would say go across, because making an X like that means technically, there is really just 2 strips going across still, would make no difference doing that than if you just welded 3 straight strips directly across (might be better even because shorter path).

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I was gonna spot weld the strips to the spot welded strip is that not a thing? Should I have planned better lol?

Oh, yeah that you can do. Thought you meant literal solder. But yeah, Minimizing distance and maximizing material is the best, shorter distance = less resistance = better.

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Also for future reference, these things. I love em for what you’re doing.

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Dang that means I’m gonna have to weld 10 little piece onto each p group :laughing: 240 pieces, that’s alot of work!

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Yeah should have gotten these, and was thinking about it, but i thought they are dimension specific for cell holders?

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A bit, yeah, but they come in spacing for 18/20/21 cell diameters. The bridge can sometimes be slightly off but for groups of 5 in a row or less, they line up close enough to do the job well.

Also you can do some math and see if you need 5 bridges per P group. Depending on your amp draw maybe 3 per group, just need to take into consideration where your S connections will be and how much current will flow through where etc.

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Planning to draw 80-100amps

Absolute max would be 120, I have been happy with my 60 amp battery, cant imagine needing 120amps lol so that comes out to less then 10amps per p group