I'm running into problems with Voltage sag, I think.
Eg: At rest, armed V=11.8. Spool up to hover power, and it drops to 10.5. Push the sticks a bit in Stabilise, and it's down to 10.0. Land, disarm...back to 11.7-11.8.
This is slightly annoying and dangerous, because both APM and the spektrum TM1000 alarms are set to 3.6V per cell...a value which is breached consistently in flight, setting off the alarms. I can set the alarms lower - artificially lower - but I don't want to do that for obvious reasons!
The quad is also do a number of auto lands, seemingly at random. Not sure why. I think it's a voltage issue.
Stats:
Quadframe quad (light), T-motor 2216-11 (900kv), t-motor 1145's, simonk 30A ESCs, maxamps 11,000mAh 3S (supposedly a good battery), APM 2.5+, Spektrum AR8000 + TM1000. AUW: 1.8kg.
Weather was cold (5'c), windy (20-25mph) with very light spotting of rain.
Logs attached, but no CURRENT logging in this run...waiting for the run to stop, so I can do another. A few heavy landings, due to wind and chasing the throttle around on the stick. These logs were the first runs post-PID tuning.
Replies
Try to grab a tlog file and post it.
They allow a playback so we can watch multiple parameters interact.
-=Doug
At 11.8v with no load your batteries are already flat.
A 3S LiPo should read 12.6v fully charged.
A single LiPo cell has an operational voltage of 4.2v charged to 3v exhausted, with a non recoverable voltage of 2.5v
All batteries will recover their voltage after the load is removed, so the no load voltage does not indicate much.
Check the battery just under it's C rating and see what sort of voltage stability you get.
Most quality batteries will hold 10.5v at their C rating for at least 75% of their discharge.
These days it is all about Lithium content.
Plenty of info on Google.