Sort of going for that shape, but low voltage
Yes, I know this flexiBMS project. I tried to contact Simos many times, but he never replied to me. Too bad, because joining force would be more productive than working apart on almost the same thingā¦ this flexiBMS has very similar level of compactness/specs than my BMS with a different form factor.
For the braking problem, once I get over 15S,18S, 24S SS & LITE BMS, I will spend time on VESC code or maybe even work on the newest & less mature MESC code directly instead. I still think 2 wire cable between ESC & BMS for CAN bus comm is a must have and requires only very little investment & hardwareā¦
once I get over 15S,18S, 24S SS & LITE BMS
I was talking about the software/firmware development + production ramp up. Not issues with the actual BMS
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From design point of view no one will use 15s set up because it is just waisted block on battery than it would always be Even number 12s/14s/16s/ or more
Actually, the 15S version is the one with the most demand so far. I guess 13 & 14S pack configuration is somehow popular in other field than e-skateboards.
On anotger topic:
Would 30mm x 100mm be too wide or too long for X LITE version? Could go xcheap & xsmall with X LITE versionā¦
For putting it into the Onewheel BMS slot, I think itās totally fine (also depending on thickness). Iād say if you wanted to make it fit Onewheel well, making it 37mm wide would mean the user wonāt need to figure out a way to secure it, whereas 30mm might be too loose in there. But itās a minor concern.
35mm wide would allow to keep the additionnal connector row for thermistor inputs and the quite large wurth terminalsā¦
Thermistors seem important 
Not sure I care about the wurth terminals (they seem like they wonāt fit in the Onewheel BMS space), Onewheel uses two XT60s (one goes to the battery and the other to the controller), have you considered those? They make things convenient - as opposed to connecting or even soldering separate wires. For a charge-only, I assume there would only be one XT60, for the battery (in addition to the charging port connector).
To make it super convenient, there could even be an XT60 for the controller even on a charge-only BMS, wired straight to the battery one. Just throwing some ideasā¦
I donāt think XT60 even xt30 connectors would fit on the board directly. They could only be soldered directly on the board creating a sort of protuberance. Soldering pads is the cheaper & smaller option so the user can place the junction where there is space. I really like having M5 screw connectors but I agree, they are quite large for e skate application.
Drawback of soldering pads is, wellā¦ user has to solder the wires on a brand new boardā¦ 
XT30PW might actually fitā¦ what do you think about this small 30A max. connector?
No answer about XT30, so I worked a few hours yesterday on it to see if it would works.
So far, it fits on a 35 x 85mm. This could be a future ācharge onlyā narrow version with XT30PW for connecting the charger on a flat battery pack.
No need for larger connectors than 30A if the BMS is only used for chargingā¦
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Started to ship some SS-18-LITE this week:
Not that they are that bigā¦ but I understand that smaller is better on this forum.
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That is simply awesome!
Even with XT60! Although Iāve just realized, the OW has swapped polarity on the battery XT60 connector, just another FM crap attempt to make it difficult for people to repair their boards. So this could cause potential issues down the lineā¦ people plugging it in without thinking etc. Not saying you should swap it of course.
Another note, tall things wonāt fit at the edges of the BMS on a OW. Not sure if you can structure it so that the connectors are in the middleā¦ the space is triangular in the thickness direction, you can hopefully kinda see in on the pictures. In case youāre really actually interested in making the BMS fit Onewheels, I can certainly provide you with more precise measurements!
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CAD would be useful to see if it fits.
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I have secured hundreds of STM32 IC lately for a premium & several LTC6813 as well. I think it is worth itā¦otherwise I would have to stop producing until they become available again on digikey/mouser etcā¦
Worldwide part shortage is getting me crazyā¦
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Thanks.
Very challenging creating new stuff, but still fun. Hope you will like it.
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Tbh. Iād just be drawing the CAD model based on the dimensions I measure and all thatāll be is the triangular profile of the OW BMS pocket (plus the length which we already have and itās not a concern). Iāll likely just send you a 2d schematic with dimensionsā¦
But, seeing as you have 3d models of your designs, if you (after I send you the dimensions schematic for a basic fit-up) send me an stl, I can 3d-print it and verify the fit for you. I think thatās a reasonably easy way to do it?
Yes, I will send you step files.
I can also try to bring the connectors more centered. Also, note that the two connectors opposed to the balance+temp connectors could possibly be removed/not populated I think. Those are for the power button & I2C display which might not be useful for most users on a charge only BMS. There is an automatic wake-up function when connecting a charger and there is also the possibility to use an external 5V enable signal coming from the connected ESC to wake up the BMSā¦
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Wowā¦ now we are talkingā¦ I guess is still 18s (and not just 15s, to have room for improvement, and even in the future for discharge too). Looking awesome. I am impressed.
Zippy is right, with the thickness. I guess now with the cad, could be adjusted easily. Thanks for the hard work!!