Removable, Sectional 10S4P

DIY Builds Battery Builds
#1

been talking about this for years with different people on occasion but ive never done it until now.

This is a sectional, removable pack that can be broken down easily. i set it up in 2S 4P sections that can be plugged into the harness in any order. The magic is in the harness, with XT60s for the series connectors and XT30s for the balance leads. The harness makes it next to impossible to plug the pack in wrong, and it doesn’t matter which one goes where.

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This method could easily scale to any sized pack.

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#2

I love the way you’re using shrink wrap to route the balance leads and the double wrap on the cell bricks to keep the I/O wires neat…but isn’t it a lot harder to get the balance leads into the BMS that way?

Why the XT30 over a 2 pin JST like the smaller charge ports use?

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#3

This pack looks exactly like what i need, beautiful!!

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#4

You only have to do it once, but it did take three times as long while triple checking with the volt meter. What you end up with is a BMS connector on one end and an array of XTs on the other end. The BMS stays in the board.

I was able to easily plug those into each other with the polarity reversed, even though they are keyed. So i tried the XT30’s and found it almost impossible to plug them in wrong. That’s important because if the pair gets revered on one of the packs you effectively short the pack and the most likely outcome is needing a new BMS, and possibly some wire. Sometimes the BMS handles this nonsense so gracefully that you won’t know what’s happening until its hot enough to melt the solder and cause the resistors to start sliding around, which causes a whole other set of issues…

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#5

That makes sense, maybe I’ll try making one with those styles one day. Also you 100% can plug an XT30 in backwards, I nuked a charger that way long ago

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#6

heres the pack sections in a more naked state before i fish papered the sides and wrapped them.

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#7

Stuffing that in a 'tipo? Or is that a Choo Choo?

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#8

@Ace :call_me_hand:

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#9

:open_mouth: :muscle:t4: :dash:

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#10

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Yes Sir! It’s #1

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#11

You must have worked at it for a minute though right? I couldn’t even get them to touch.

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#12

I had plugged it in once per day when I used the board for about 3 months, one day I happened to plug it in backwards and poof

I had soldered it with a weak iron so may I deformed the nylon?

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#13

i’ve thrown so many plastic connectors away because of that… but i refuse to turn my iron down because i’m a man.

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#14

Fat tip 480C gang?

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#15

I see two balance leads from each pack
Are these coming from each of the two (+) or (-)?

I assume the last (or first) BMS’s wire comes from the harness, is that right?

Fucking genius

#16

OH SHIT yes. I got a full back tattoo. So in.

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#17

Coming from the two positives. The series connectors come from pack neg and pack pos, but balance comes from each pos.

#18

I guess you also could have done a single middle balance lead from the bricks and pulled the other 6 balance leads from the harness? I have an ass load of bread board pins in M/F

Absolutely no way to fuck that up :yum:

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#19

using only one pin on a two pin connector would guarantee correct connection, yeah. Great idea.

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#20

Particular reason you pull balance from the positive? Usually I pull negative so the tabs are on the cell can and can’t short, but I suppose it doesn’t matter if you have those pads