Experienced a sp hard cutoff

Watch on YouTube if it doesn’t start on this page. Enjoy!


Glad that happened at a safe landing place!
The system definitely needs a better management about end of discharge. More warning, reduced power instead of hard cut. etc. Guessing “about 30%” is not good for a newbie. I will try to make this kind of improvement after I get my unit.


That’s a surprise. I would have expected that 30% is a large safety margin and that at least some power would be available until close to 0%.
Makes me wonder if the battery % measurement displayed is wrong?

It’s not wrong, it’s just the calculation is based on battery voltage, and the cutoff is based on battery voltage, neither takes into account voltage sag due to load. So there’s some variability. Counting Ah should be better, I’ll test that soon.

Under a load it’s more like 5-7% at cutoff. I usually land at 10% when trying to climb.

I’ve started another thread on this issue. The BMS is doing its job: protecting the battery. The combination of the ESC and Throttle controller need to be involved in avoiding hard cuts. Cell voltages need to be monitored such that they are not allowed to sag to the BMS log voltage limit by limiting current (power).

See BMS hard cuts - suggestion in the Throttle Controller section.