hi I noticed a thread further down the forumfor a poor flight time on a s900,I had a similar problem on mine yesterday.mine is a s900,a2,z15,nex5,and lightbridge setup. I used a brand new fully balance charged gens ace tatty 16000 mah,took off and done some gentle flying and hovering,after just under 7 minutes the first voltage protection had kicked in! The lightbridge battery monitor flashing at 22 volts,the craft was landed and battery tested and showed the battery was at 23.3 volts.the battery was calibrated in the assistant,is this a firmware issue? As I have read similar problems on other forums with th a2 since firmware update?.

I took out my new s900 a2 gh4 for it's maiden flight today and experienced the exact same thing on 3 different batteries. The voltage on the lightbridge osd was all over the place and I landed right at 22.2 I checked them at home and they are all at 23.8

I have an S1000+ with A2/Lightbridge/IOSD MK II/900 mhz Datalink/Zenmuse Z15 setup carrying a Sony A6000 camera.

First, I learned that the voltage reading is very dependent on the load or strain on the motors. If you fly around with a 23 volt reading and then land, as soon as the strain of the motors isn't lifting the UAV anymore, the voltage reading goes back up above 24. Take off again, the voltage goes back down, land again, the voltage comes back up. To get a useful idea of how much battery capacity I have left at the end of a flight, I hover just before I land, because once you land, the voltage meaning is useless.

Second, I once disabled the "low voltage land" option on a calm day and started with a full battery, flew around until the voltage showed 22 or so, then came back and hovered with the platform positioned so that i could see the LED. Sure enough, it flashes yellow, then red, but the platform is still flying fine.

At somewhere down near 20 volts, it took more throttle to stay in the air than usual, but I was still flying, and could still ascend if I needed to.

At about 19.5 the beast settled nicely down on the ground with the throttle pushed to max.

I went home and changed my yellow warning to 21, and the low voltage land to 20.5

The battery supply ability is not a flat line, however. The drop from 24 to 23 could be 5 minutes, but the drop from 20 to 19 could be 30 seconds.

Since the S1000+ requires 2 controllers, one to fly and one for the camera, my wife is a biologic voltage warning on most flights. She used to be screaming at me at 23 volts, but now her voice doesn't show concern until about 21 volts.

I have flown under 21 volts many times, and can't tell any loss in battery capacity.

Depending upon how teenager-unlike I fly, I can usually expect near 19 minutes with my 15000 mah batteries.

I suggest you disable the autoland on a calm day, make your wife watch, then discover the other 40% of your batteries you've been landing with, LEDs ablaze

We fly Tattu 12,000mah packs on our S900+A2+GH4+LB - OSD shows a voltage drop of about 1.0-1.2 volts when the machine is flying vs. voltage once landed.

We find the packs discharge at a constant rate down to 21.6v and then hang on for a while. We tend to land once we hit 21.2v which sees about 30% left in the pack. Flight time is approx. 10-11minutes.

Regarding initial post, as you can see from other posts you can fly down to 21.6V (underload) with no problems...this is what my initial warning is set for and I'm down within 30 seconds afterwards and have never had a post flight battery showing less than 3.7V per cell (resting).  Battery death is around 3.5V so I would not follow the advice of previous posters who is flying down their underload voltages down to 21V!!!  While they think their batteries are fine, one day soon their batteries will begin to fail and hopefully not during a flight.

Secondly if you upgrade to the E1200 propulsion system and fly down to 21.6 (underload) you'll get 15 plus minutes not problem.

For test purposes only, I fly an S900, E1200Pro, A2, DataLink, Tattu 22000, WITHOUT gimbal.
Static flight (2.5m height, no wind): starting voltage 25.2, total flight time 38 minutes, end voltage 21.9
Slow movement flight (20m height, no wind, gust 15 knots): starting voltage 25.2, total flight time 38 minutes, end voltage 22.0
I receive the first voltage alert (yellow warning with standard setting, 22volts) in both flights at the 21 minute of flight.

acosta1962 Posted at 2015-11-7 11:42
For test purposes only, I fly an S900, E1200Pro, A2, DataLink, Tattu 22000, WITHOUT gimbal.
Static flight (2.5m height, no wind): starting voltage 25.2, total flight time 38 minutes, end voltage 21.9
Slow movement flight (20m height, no wind, gust 15 knots): starting voltage 25.2, total flight time 38 minutes, end voltage 22.0

If you got the 22V alarm after 21m how did you get over 30 and land at 21.9?

Hi, old post but I need to add to this, any help would be appreciated.
I have flown a s900 before and never seemed to have had battery sag as bad as a recent s1000 purchase.
I have a s1000 and flying with tattu 16000mah, I had tested without gimbal for roughly 1 min, landed and put the gimbal on Gremsy t3 v3 with sony a7r2, fairly heavy setup but within the payload capacity
Launched again and s1000 flew for about 1 min before entering the first battery alarm, this was roughly 2 mins of flying at low level.
The gimbal is powered from the main battery but I would doubt that this would be the problem but more of the weight and bat sag
I then landed added another tattu 16000mah battery and lastd similar roughly 3 mins, the battery after landing reads 24.05v so no where near the 21.6 failsafe landing .
What would you recommend for battery settings as I obviously dont want the drone switching to fail safe landing over water.
Thanks in advance