Hi everyone, I have been going back and forth on this one and would appreciate your comments.
I build my own 6s7p battery (NCR18650) which takes up so much space that I will very likely never go above 6s. Given that, what would you recommend, the FVT120A or the HK VESC (“turnigy esk8 esc”)?
Other parts
70mm wheels (will upgrade to 90mm eventually)
HK motor mount + pulleys. 15mm belt. Gears: 15 (drive), 36 (wheel)
SK3 6364 245kV
Been running all that through the esk8 calculators out there, amp draw, top speed etc. are all within limits and ok for me.
However,
I keep reading 6s is at the Amp limit of the VESC, so higher risk to fry it (already seems quite high risk anyways…). The VESC mosfet’s limit is 50, and I want to be able to draw at least 50 or 60 battery amps to have enough power for the board. So I would definitely operate at the limits, especially when I upgrade to 90mm wheels. Is the VESC with 6s worth the risk?
I am guessing the FVT 120A with the “161214” (brakeLine / linear brake) firmware will hold up better with 6s. At least there seem to be many more 6s builds out there that use this one instead of the VESC.
I dont mind losing the configurability of the VESC, if I get better reliability in exchange for less options and features.
I would not run the VESC on 6s… you pull too many amps. I have had good success with the FVT 120a on my first build (not sensored) and the new firmware. Some others have blew the FVT but I believe most of them were running sensored.
update: I bought the FVT 120A, and disasembled it to remove the original caps and solder new ones horizontally, removed the fan and the top case to reduce overall height to about 20mm (want the enclosure to be nice and flat…).
Doing so, I took a picture of the PCB with the MOSFETs there, and found their datasheet:
One thing that may make a difference though is that the FVT 120A ESC has a total of 24 power MOSFESTs (12 on the front and on the back), the VESC has 6.
I am wondering where these recommendations come from that the VESC does not like 6S and will overheat because of too much current. Are there any users out there where the VESC actually overheated at 6S?