I had a onewheel. It broke.
here we are.
I made a model of it stock.
Now it is time to revive it with a serious force!
I made a model of it stock.
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These are molicell P42a cells against the case profile. Looks possible to fit that with a bit of effort
Issue being that is 19 cells, not 20. So you could do 19S2P… OR
you could do this stupid shit!
yeah. That would be pretty solid.
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Looks like you have to stick with 18650 then. Those don’t fit, not with fishpaper and what you need to do it right.
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What amount of clearance between cells is required?
I think fishpaper is 0.25mm so one of those between the cells and one around the whole thing, and I think Molicel 21700 might be about 0.3mm (or 0.7? I forgot) bigger than 21mm.
And then polyimide tape…
and balance wires and nickel
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Comparing those 2 cells by just entering 2.6Ah and 3.0Ah in the esk8 calculator is not a good comparison.
You look at graph, look at how they both end up at 2Ah at 3.2V under a 10A load, see that P26a’s red line is higher than 30Q’s blue line meaning it sags less, and you pick it.
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this
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I was only concerned with range, real testing for voltage sag would be best!
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In the real world you will be drawing constant power for the same riding style, not necessarily constant current. So if a cell sags less, then it provides more voltage, meaning it’ll use less current, and ultimately give you more range. Think of the area under the curve as the total energy provided by the cell.
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The only strict requirement is the profile I showed, because the rails can be easily extended but not in other dimensions.
sorry meant to have dimensions in the last pic.
Both I am hoping to have room for once the box/rails are extended
Guessing I would need like 10 more mm
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Do you want to keep the original hub motor of the v1?
I have heard that it performs somewhat poorly even with VESC. It’s like 500w nominal. With a 20s 3p that’s only 2,3A per cell. You could probably consider 35E at this point.
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@b264 get him
What else would I do with it? lol I am working on an entire new hub but that is later.
Given I am the only person to mess with one, what did I say exactly? I could not get it to work with v4 VESC HW/FW is all I said.
500W is what they run it at, I think it could handle a wee bit more accounting for safety margins.
Wish I still had it running so I could check the amp draw…
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What’s wrong with 35E? They are fine for those low power applications. You have 60 cells for Like 500-800W. 10A continuous discharge per cell like the graph above is completely unrealistic for your OneWheel.
The only problem is that 30q and 35e are stupidly expensive right now so you might need to go with p26a. But I’m pretty sure they have the worst range out of the 3 in your case.
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P26a are the only 18650 cells that are really good for a 20S2P I would say.
Speaking of I want to try to make a battery box with swappable packs.
The footpad would flip out of the way and then you could pop the battery out. Or maybe there would be an access hatch in the footpad as well. Who knows.
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Someone asked me to check the fit of 18S2P 21700 in the stock XR case as they thought it might work.
They were right it could be possible, but only with 21mm cells or less without modifying the lid and spacing the footpad.
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There’s a guy on Facebook in the Onewheel Vesc Builders group that is working on an injection molded battery box that will hold 19S2P 21700, are you aware of that? Might save us all quite a bit of work.
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oh well shit I gotta see that!
In that last pic I posted I was not taking advantage of the lid space so 21700 cells can actually fit like in
In the stock XR battery case
Only issue being it is too long overall, so there would need to be some mods to the case to make this work.
oh I have a feeling these will fit good
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That printed part was a battery case that failed and now I am just gonna use it as a test frame. Eh. Should work.
8 up front and 16 in the rear
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The blue battery above was just for show. That pack is super rekt.
Anyways this is a thing now
Each positive wire has a male bullet and the negative a female.
I almost made Balance wires for each but now for this amount of testing it should be ok, easy to add later
I think you could make a custom rear footpad with concave and then hide the extra clearance height needed for putting the 8 cells on top of the rear pack. instead of in the front box.
fitting a 24S1P A123 into the stock case dimensions mostly would be super awesome
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