a VESC controller for 22S ?

[samv76]

Hi all,

I searching a controller to replace the current one in my e-scooter.
I like the thought behind the VESC and the software seems pretty good from what i have seen.

The thing is i have seen one for 20S and it has a max rating of 100V. This seems to be an absolute maximum ( limited by the 100V FET's ? ) but my 22S battery pack is 100.8V fully charged.

Has anyone heard of a 22S Vesc controller out there of would it be possible to modify the 20S VESC to handle the 100.8V of my pack?

regards,

Sander

 

[john61ct]

Not just VESC but in general things get very rarified above 20S

Lots of devices can just barely handle 21S, keep the charging voltage well below full at 4.15
88V really is the right max, giving margin for cheap-chinese components supposedly rated for 100V

Above that you need to keep spares on hand, or start paying a lot more for higher quality gear, starting to get into EV stuff.

The top-speed difference is likely very minor, do you really "need" to go that high?

 

[dominik h]

You have 24S with 100.8V.
Just charge only to 4,15V per cell (99.6V).

But I don't know if a 20S vesc can handle this.

 

[samv76]

Not just VESC but in general things get very rarified above 20S

Lots of devices can just barely handle 21S, keep the charging voltage well below full at 4.15
88V really is the right max, giving margin for cheap-chinese components supposedly rated for 100V

Above that you need to keep spares on hand, or start paying a lot more for higher quality gear, starting to get into EV stuff.

The top-speed difference is likely very minor, do you really "need" to go that high?

I didnt really plan on 24S my 20S battery pack died, and i could get my hands on some samsung SDI power pack modules.
They come in 12S so i put two of them in series. I already had a bms that could handle 24S
I could convert back to 72V but that would mean i have to open one of the packs and remove some cells. Seems like a lot of hassle. But given the major up pricing of 96Vs 72Volts i might do it if i cant find any affordable controller

 

[samv76]

You have 24S with 100.8V.
Just charge only to 4,15V per cell (99.6V).

But I don't know if a 20S vesc can handle this.

yeah i thought of that but i guess it would depend on the quality of the used parts? my 73V Sevcon gen 4 controller has no issues whatsoever with running on 100 volts. it doenst even get warm.

 

[mxlemming]

24s is definitely death for a 100V VESC. It might work for a bit but the dcdc converters are usually the ti 100V ones and die pretty easily.

Don't do it. I think sevcon has a more robust dcdc stage, there's some degree of isolation.

 

[j bjork]

You have a 24s pack, so you want a controller that can handle a 22s pack?
Either way, a fardriver 84xxx should work. Or sevcons 80V controllers as mentioned.

 

[samv76]

You have a 24s pack, so you want a controller that can handle a 22s pack?
Either way, a fardriver 84xxx should work. Or sevcons 80V controllers as mentioned.

Wow, i totally messup up there :lol: i guess i was more tired than i thought when i posted it.
But yeah i have a 24S pack , so i guess i would need a 24S VESC.

The fardriver 96 is on my shortlist for the moment. My SeVCON is a pretty solid controller but programming it is a nightmare.

 

[samv76]

24s is definitely death for a 100V VESC. It might work for a bit but the dcdc converters are usually the ti 100V ones and die pretty easily.

Don't do it. I think sevcon has a more robust dcdc stage, there's some degree of isolation.

Would a solution be so simple as to replace some of the DC/DC stage parts for something rated to 120V? or am i just talking nonssense now?

 

[mxlemming]

24s is definitely death for a 100V VESC. It might work for a bit but the dcdc converters are usually the ti 100V ones and die pretty easily.

Don't do it. I think sevcon has a more robust dcdc stage, there's some degree of isolation.

Would a solution be so simple as to replace some of the DC/DC stage parts for something rated to 120V? or am i just talking nonssense now?

Yeah this would probably work. The MOS themselves would be the next to go.

MOS are rated according to their leakage at Vds. They don't instantly die at 100V unlike the dcdcs, they get increasingly hot and then die at 10-50V over depending on manufacturer and the wind direction.

If i was doing this I'd just rip out the whole dcdc stage and replace it with an isolated xyzV to 12V converter

 

[samv76]

24s is definitely death for a 100V VESC. It might work for a bit but the dcdc converters are usually the ti 100V ones and die pretty easily.

Don't do it. I think sevcon has a more robust dcdc stage, there's some degree of isolation.

Would a solution be so simple as to replace some of the DC/DC stage parts for something rated to 120V? or am i just talking nonssense now?

Yeah this would probably work. The MOS themselves would be the next to go.

MOS are rated according to their leakage at Vds. They don't instantly die at 100V unlike the dcdcs, they get increasingly hot and then die at 10-50V over depending on manufacturer and the wind direction.

If i was doing this I'd just rip out the whole dcdc stage and replace it with an isolated xyzV to 12V converter

the wind direction lol. Well since the controller is located under my seat it would be a bit of a pain in the #ss when it goes poof. :lol: