You are here

BATTERY_VOLTAGE_HIGH_CUTOFF_START // CUTOFF_END ?

1 post / 0 new
Andy G
Offline
Last seen: 6 months 1 week ago
VESC Original
Joined: 2017-05-24 12:31
Posts: 2
BATTERY_VOLTAGE_HIGH_CUTOFF_START // CUTOFF_END ?

Hi,

Are there still plans to implement "Battery Voltage High Cutoff Start" and "Battery Voltage High Cutoff End" that is, in theory, the exact opposite of the Battery_Voltage_Cutoff_Start // End script that is already implemented?  I realise braking will be less consistent when the battery is >95% full, but I cannot afford to keep buying / repairing VESCs.

I live on a hill and BMS-overvoltage-cut-outs have caused a number of my VESCs to die over the years - 3 so far (6 if you count per vesc).   I have tried to follow a "no braking when fully charged" rule which has helped and also trying to stop each charge at 4.15v/cell (whilst lowering the balance voltage to 4.0v), but occasionally I forget that the pack is full, where upon there follows a 50:50 chance of blowing TVS Diodes and DRV chips.  I am now trying with a reduced "Maximum Input Voltage" (reduced to 52V) to create some headroom between when the VESC throws a fault and shuts down and when the voltage spike starts to detonate components!

I have a 12S pack, where the "Smart" Ant BMS will disconnect on over-voltage at 51v, however this is very close to the voltage when the TVS starts to conduct and components start to die.  I am thinking that the VESC does not have enough time to disconnect the phase wires before the voltage spike is frying things.   On a full pack I can blow the TVS by simply spinning the wheels up to full speed in free air, then applying brake....  Reducing the brake current setting is not really an option as I like to be able to stop quickly (when the battery can take the regen).

Any suggestions or pointers would be welcomed...

I ask as I don't see this on the list of "yet to be implemented" items.

Thank you