Flight time to first low battery warning

[RBC]

After about 25 cycles of babying my battery, I decided to fly until I got my first low battery warning. It was dusk outside and watching the H's lights is so cool. I took it up to 400 feet and flew west about 1,400 ft and then brought it back overhead and flew it 1,400 ft in the other direction. I lost sight of it at one point so did a RTH and I could hear the H before I could see it. Total flight time was 18 minutes, but the last 3 minutes was very slow flying and hovering as I did not want to be far from home when I got the low battery warning. Battery was at 14.3v when I got the flashing lights on the H and the ST16 started vibrating. One of the things I also noticed is that when the H was hovering, it would drift in a small circle, maybe about 3 feet . There was a light breeze but nothing more than 8 mph. This made it a little bit of a challenge to land. I did not want to drag the landing gear. I let it get within a few inches of the ground and waited for it to stop drifting and quickly put it down. What I am beginning to see is that it is much better to land in an open area without any nearby obstructions. A safe landing is much more forgiving in case the H begins to drift.

 

[Steve Carr]

After about 25 cycles of babying my battery, I decided to fly until I got my first low battery warning. It was dusk outside and watching the H's lights is so cool. I took it up to 400 feet and flew west about 1,400 ft and then brought it back overhead and flew it 1,400 ft in the other direction. I lost sight of it at one point so did a RTH and I could hear the H before I could see it. Total flight time was 18 minutes, but the last 3 minutes was very slow flying and hovering as I did not want to be far from home when I got the low battery warning. Battery was at 14.3v when I got the flashing lights on the H and the ST16 started vibrating. One of the things I also noticed is that when the H was hovering, it would drift in a small circle, maybe about 3 feet . There was a light breeze but nothing more than 8 mph. This made it a little bit of a challenge to land. I did not want to drag the landing gear. I let it get within a few inches of the ground and waited for it to stop drifting and quickly put it down. What I am beginning to see is that it is much better to land in an open area without any nearby obstructions. A safe landing is much more forgiving in case the H begins to drift.

Good information. I haven't flown to the low bat warning. I get tired before that point. As far as the drifting, I would normally suspect the accelerometer calibration. Set the H on a level surface, turn it on and make sure it doesn't get moved until it's booted up. Then do the cal with the ST16. Also, be sure to launch from a level spot. Booting on a slanted surface can result in poor performance.

 

[snerd]

Yes, I've seen the 3-foot circle of near-death lol! After compass calibration and accelerometer calibration, it disappeared.

 

[RBC]

Good information. I haven't flown to the low bat warning. I get tired before that point. As far as the drifting, I would normally suspect the accelerometer calibration. Set the H on a level surface, turn it on and make sure it doesn't get moved until it's booted up. Then do the cal with the ST16. Also, be sure to launch from a level spot. Booting on a slanted surface can result in poor performance.

I had calibrated my accelerometer just before this flight. So this has got me wondering what else it could be.

 

[Dragonflyerthom]

RBC if you have done all of the calibrations then it had to be the wind.

 

[Steve Carr]

I had calibrated my accelerometer just before this flight. So this has got me wondering what else it could be.

I'd do it again. I carry a small piece of plywood and a level in case I need to cal the accel. I've found this to be a critical calibration for smooth hover. For station keeping the accelerometer and gyro are doing the work, not GPS.

 

[Dragonflyerthom]

Wow Steve you seem to be gung-ho on this. Keep us posted on your adventures.

 

[PatR]

The accelerometers should only need to be calibrated once if it is done right. The compass is actually pretty important when in a hover since GPS is not a primary means of guidance. If the compass was not calibrated properly, like not pointing north at the start of the process, some "hunting" could be expected as the compass interacts with the altimeter to hold orientation and altitude. GPS is used to set position. We should remember that GPS precision is not an absolute and can vary by a couple meters or so.