VESC BMS

[princesswolfie84]

Any one find a BMS that works and communicates with any VESC? im looking to get a new bms for my cheap battery as i don't believe the bms that's on it is actuly doing anything at all. I'm also about to upgrade to a fs75100 from an ancient dual 4.2 unit i had from my esk8 days. If no one has found a vesc "compatible" bms what are your suggestions for a good one with some way to monitor the battery?

 

[john61ct]

I have not yet heard of any BMS designed to communicate with any controller.

What sort of commands or signals are you imagining?

Which would be slave and which master?

The BMS is not supposed to do anything in normal operations, only as failsafe back protection when the infrastructure fails, to protect the battery from getting destroyed, HVC and LVC based on cell-level voltage readings.

Then you may have balancing functions, but not necessarily, cheap BMSs are usually very badly designed for that.

Sometimes the very expensive BMSs may control the very expensive chargers, through CAN messaging.

 

[princesswolfie84]

So the current version of vesc firmware and matching software tools alow a bms to be programmed and monitored over can bus. I was hoping to take advantage of that so I don't need a second software suite to program and monitor my battery. My current bms clames to have over amperage protection as well as over voltage and under voltage. I would like a bms that has all of these and over temperature protection as well as I live in florida and the environment itself can be pretty hot lol. I also would like to be able to program these protections and monitor them that way I can check on the health of my pack and address issues before they become a ball of flames.

 

[Ugothakd]

Following. The vesc has amp protection and low voltage cutoff last time I checked so you don't even really need a bms. Lots of guys in the sk8 forums were using "charge only" bms's with great results. 5 years ago, though, things may have changed

 

[john61ct]

Yes really "a BMS" is just a given set of functionalities.

PER CELL / group voltage monitoring

Failsafe LVC and HVC protection backup for when other infrastructure fails

These two I consider worth using a BMS for, but ALL can be implemented otherwise.

But the QUALITY reliability, longevity cannot be assumed, regular testing is required

And build your battery so the BMS can easily be replaced / removed

Never leave it attached to the cells when the pack is not being cycled.

rare:

High and or low temperature cutoff

rarely implemented well:

Over-current

Balancing

 

[princesswolfie84]

Vesc it self can control howmuch amperage it pulls from and gives to the pack. It can also turn off output when the input voltage falls to a given degree. These are great and things that need to be set.... but they do nothing for high temperature issues. Lithium batteries are very robust things and you can push them to enormous extremes. As long as u can make sure there not getting to hot. They thermally runaway at certain temperatures and that's what tends to cause most pack fires. Yes they may have been being drawn from to hard or charged to hard but if there was a cut of at temperature u can stop that from happening. Being able to see per cell voltages and keep them balanced will make it so your $600+ will keep working for much longer than a year or so. And being able to set and know the limits the bms is working with helps to insure these things are with in parameters for your given cells. Maby I'm just weird because I want real protection for something that my crotch is basically sitting on that can go boom ish

 

[Oli.Hall]

ENNOID BMS, AFAIK is the only commercially available BMS that does exactly this:

https://www.ennoid.me/bms/ss

NEW feature for 2022:

VESC & VESC-tool CAN & USB compatibility for firmware updates, data monitoring & parameters configuration

DIEBMS is the original open source version from which the project above was developed.
https://github.com/DieBieEngineering/DieBieMS

And MK-BMS (Aliexpress) which is a China clone of the ENNOID BMS above also does something similar.

Thanks,
Oli.

 

[john61ct]

Yes great find

https://endless-sphere.com/forums/viewtopic.php?p=1691648#p1691648

https://endless-sphere.com/forums/viewtopic.php?t=92952

https://endless-sphere.com/forums/viewtopic.php?p=1360443#p1360443

https://endless-sphere.com/forums/viewtopic.php?p=1675361#p1675361

 

[Ugothakd]

Vesc it self can control howmuch amperage it pulls from and gives to the pack. It can also turn off output when the input voltage falls to a given degree. These are great and things that need to be set.... but they do nothing for high temperature issues. Lithium batteries are very robust things and you can push them to enormous extremes. As long as u can make sure there not getting to hot. They thermally runaway at certain temperatures and that's what tends to cause most pack fires. Yes they may have been being drawn from to hard or charged to hard but if there was a cut of at temperature u can stop that from happening. Being able to see per cell voltages and keep them balanced will make it so your $600+ will keep working for much longer than a year or so. And being able to set and know the limits the bms is working with helps to insure these things are with in parameters for your given cells. Maby I'm just weird because I want real protection for something that my crotch is basically sitting on that can go boom ish

Thermal fuse shouldn't be too hard to implement, if you are concerned about per cell voltage monitoring breakout a multimeter and check. Put a few jst connectors so you can check. You make it seem like that is your priority, so put a thermistor in the pack with a microcontroller and a fat relay. As the other user mentioned a bms is just a compilation of features

 

[Ugothakd]

ENNOID BMS, AFAIK is the only commercially available BMS that does exactly this:

https://www.ennoid.me/bms/ss

NEW feature for 2022:

VESC & VESC-tool CAN & USB compatibility for firmware updates, data monitoring & parameters configuration

DIEBMS is the original open source version from which the project above was developed.
https://github.com/DieBieEngineering/DieBieMS

And MK-BMS (Aliexpress) which is a China clone of the ENNOID BMS above also does something similar.

Thanks,
Oli.

Holy ****, I'll take my chances with unprotected cells before I spend $200 on a bms. Maybe if you have a few kw battery pack it makes sense, but for the 12s2p and 13s2p packs I have planned absolutely no way would I drop that kinda coin. Costs over double the cells.

 

[Hummina Shadeeba]

Voyage Systems

voyagesystems.eu