Sure, take the 15S version. Unused upper cell pins all connected to the last pin used. There is this info in the user guide on SS ENNOID website page
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Do you by chance have a rough estimate on the 18s Lite version? 
Thx, I guess I should have RTFM. 
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I might have time this week end for testing the 5 first āSS-18 LITEā boards assembled. If everything goes well I could probably ship in a week or two for those first couples units, but keep in mind, the LITE version were listed for shipping by the end of April on the website from the beginning.
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Small update for the long awaited SS-24: it fits on 100x60mm board:
The āLiteā version should normally also fit of 60x65mm
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With other bmsās I have had problems with the cell hard overvoltage cutoff. The problem is that it works as intended.
When the battery is full then it is very easy to spike the voltage over 4.2v while breaking. I propose two ideas how Ennoid could fix that
The cutoff should be a 3-5sec voltage average.
When you accelerate then the pack sags and when you regen it spikes. If you do an emergency brake on a full pack then this should even things out and the bms will not cut out.
There is an even more complicated way to do it. This is what I call a smart cut off. It is based on the energy balance. The bms knows how much Wh is depleted and how much is regenerated. When the depleted/regen balance is >1 then it should not cut off. This mode should only be used when vesc reports it is regenerating.
There is a setting called ādischarge hysterisis valueā which is meant for preventing cut off when the battery is almost fully discharged. There is soft max cell voltage which is used during charging and which should be lower than the hard cell max limit which is used during discharge User can adjust those values so in case of regen the BMS should not cut off even if the voltage goes beyond the max soft overvoltage limit. But even with that I agree it might not be the best way of doing this. The better way is with agrement between ESC & BMS im a similar way to what you are proposing. This can be implemented/tested in future firmware updates on the CAN bus.
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Been playing with the idea of a 3dprinted PETG plastic case recentlyā¦ I thought that some folks might want a case with the BMS. It also looks more like a finished product with a case, but I wonāt use this myself for my packs.
I donāt know what to think about it honestly. It should at least survive heating from balancing & discharge.It canāt be perfectly sealed with 3d printing & without moulding, but it hides most sensible electrical partsā¦
Anybody have something to say about this? Idea? Use of some metal plate for cooling?
Here is a pic of an initial attemp for a 3dprinted case for SS-15 board
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I definitely think that the case is a good idea. I would just make sure that it doesnāt add to the total volume of the board in any of the dimensions by more than a mm or two.
Iām at 2.5 all around. So, the SS ends up at 65x105mm. Lite version would be at 65x70mm with the case.
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Iād personally prefer it without a case, but it would be nice to have an STL to print that gets sent over after ordering.
Personally I plan to have the BMS inside the pack, so at least for one build I wouldnāt want the case.
Idem for me, Iām putting the BMS inside my battery packs, so I donāt need a case.
For the one that needs it, I will put the 3D STL files directly on the website page once the design is good enough.
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@ENNOID can you share your website link at the beginning of this thread or point to where I should find it?
Canāt edit any of my previous post. I guess I should ask moderator to upgrade my permissions.
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I2C Temp+humidity sensor
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Been a while since I checked in hereā¦ that 15s lite is looking damn fine!
Big props to you for making this stuff happen dude, seems like you are getting shit done!
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Thank you, the ENNOID product lineup is getting quite satisfying. 15, 18 & 24S BMS board in both FULL & LITE version for LEV. I must stilo work on a few details related to the BMS that Iām not yet satisfied (bluetooth app, CAN upgrade in the firmware, etc) before moving to my next targets ā¦ Iām planning to release my DIY battery packs later & will move on to ESC design. The target is to offer the whole BMS, packs & ESC that fits together. One day this will happenā¦
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Excited to order this BMS. Do you have any plans to work on 24S soon? My Motorcycle works in 24S 72V LiFePO4 Battery.
The 24S board design is complete (see the associated post from last week on this thread)
Iām ordering PCB this week for 24S, but donāt expect shipping of beta units before a month or two at best. I must do some basic reliability testing first & validate design. A lot of new components are being used for the 24S version due to higher voltage level & also using two balancing IC instead of only one. I also had to switch to more expensive 150V rated ICs for the power supply & the fet driver.
Hopefully, no firmware changes are needed for the 24S board, so this should make things a bit faster.
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