Hit battery failsafe, was it voltage or mah?

Trying to diagnose an issue here. I’m using multistar 10c 4s 6600mah batteries. My copter has sunnysky v3508 700kv motors with 12x6 props. Ecalc says I should only be pulling 17.75amps at hover.

Today 2 min into a flight with a fully charged battery I hit the battery failsafe. But I’m not sure if it was a voltage failsafe or a mah failsafe, is it possible to tell from the logs? Looking at mission planner after I realized I may have had my battery capacity set wrong. I now think youre supposed to set how much mah you want remaining when the failsafe triggers. So if I want 20% of my 6600mah when it hits failsafe I set it for 1320. I had it set near the capacity of my battery, mine was set at 5500mah, I was thinking warn me when i’ve used 5500mah of my battery. So i’m wondering if this is why my failsafe triggered, because after two minutes i was down to 5500mah left?

Battery capacity (BATT_CAPACITY)

More good reading at:


From above:

Failsafe battery milliAmpHours (ArduCopter:FS_BATT_MAH)

Battery capacity remaining to trigger failsafe. Set to 0 to disable battery remaining failsafe. If the battery remaining drops below this level then the copter will RTL

Increment: 50
Units: mA

Battery capacity (BATT_CAPACITY)

Capacity of the battery in mAh when full

Increment: 50
Units: mAh