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Duration of Tornado H920 Plus flight time
- Thread starter giafogiafo
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PatR
Premium Pilot
Better would have Yuneec posting public info updates on their website covering known issues and correction progress.
I just charged 3 of my batteries last night with the A10 and set on "Balance," 4.2Amp and 6S.
The cells are all slightly different on 7 batteries, but the widest variation is 4.10 to 4.18. Is that balanced??
The cells are all slightly different on 7 batteries, but the widest variation is 4.10 to 4.18. Is that balanced??
PatR
Premium Pilot
That's not super great but that's only 8/100's of a volt between all 6 cells. It would be beneficial to check the battery's internal resistance to see where that's at.
A theory I have is that all the Yuneec 920 batteries were made in only a single production run. Since Yuneec did not sell very many 920's there would have been no need for a second or more battery production run had the original run provided sufficient quantity to fulfill orders as they've come in. That original battery batch would have occurred a little over two years ago. A lithium polymer battery starts out with a natural life cycle limited in two ways, calendar age and number of charge/discharge cycles. Old age for a li-po is roughly two years and if they are handled correctly the number of useful charge cycles is generally between 200 and 300. There have been people buying new 920 batteries that are experiencing puffing in the first few cycles. We don't know how old the batteries are but they have a very low "C" rating, estimated at 8C-10C. The more demand you place on a low C rated battery the more they get beat up and the faster they age. Unfortunately we have no way to find out how old the batteries are unless Yuneec elected to share that information.
We should also expect that using the EC-3 connector has likely induced a lot more resistance than necessary with energy transfer between the battery and aircraft. More resistance, which reduces voltage, generates more heat, more heat generates a shorter battery life. The EC-3 is not a high amperage connector. It would be interesting to log the current load on a 920 during lift off and at full throttle operations. If that load exceeded 60-70 amps (I would expect it to be between 70-110) the power connectors could be quite limiting.
A theory I have is that all the Yuneec 920 batteries were made in only a single production run. Since Yuneec did not sell very many 920's there would have been no need for a second or more battery production run had the original run provided sufficient quantity to fulfill orders as they've come in. That original battery batch would have occurred a little over two years ago. A lithium polymer battery starts out with a natural life cycle limited in two ways, calendar age and number of charge/discharge cycles. Old age for a li-po is roughly two years and if they are handled correctly the number of useful charge cycles is generally between 200 and 300. There have been people buying new 920 batteries that are experiencing puffing in the first few cycles. We don't know how old the batteries are but they have a very low "C" rating, estimated at 8C-10C. The more demand you place on a low C rated battery the more they get beat up and the faster they age. Unfortunately we have no way to find out how old the batteries are unless Yuneec elected to share that information.
We should also expect that using the EC-3 connector has likely induced a lot more resistance than necessary with energy transfer between the battery and aircraft. More resistance, which reduces voltage, generates more heat, more heat generates a shorter battery life. The EC-3 is not a high amperage connector. It would be interesting to log the current load on a 920 during lift off and at full throttle operations. If that load exceeded 60-70 amps (I would expect it to be between 70-110) the power connectors could be quite limiting.
It may be possible to modify the connector plate in the H920 to mount AMASS XT90 connectors. They are rated 90Amp continuous and and should take 120-130 Amp bursts. I will see what the size difference is from the EC-3.
We still need a fix for the 7 minute battery warning though. (Obvious-sorry).
We still need a fix for the 7 minute battery warning though. (Obvious-sorry).
PatR
Premium Pilot
Yes. The 7 minute warning needs a fix.
I did time it today and I got 13 more minutes after the warning, BUT, the camera and autonomous functions were unusable since I had a big red warning sign that would not go away.
I am also suffering the pangs of buying used. 5 of the 7 batteries I got are slightly puffed; to the point that it is a bit of a squeeze to get 3 of them in the compartment. They all charge up to 4.1x V, but may not be usable for long.
I also found a mystery broken component in the battery compartment and loose plugs on a circuit board at the back of the battery compartment. One plug hanging loose but I don't know if it is supposed to be plugged in or not or where. It looks like there is a suitable socket close to it.
I was able to push the other plugs in a little more but they still don't look fully seated in the sockets.
I will attach photos.
Will someone please look at the back of their battery compartment and tell me what it is supposed to look like? Are all of the plugs in the sockets? Or is this an accessory plug for something?
Also, is there a G4 camera plug somewhere in there? I have a G4 gimbal for the H920 I would like to use sometimes instead of the CGO4.
View media item 618View media item 619
I did time it today and I got 13 more minutes after the warning, BUT, the camera and autonomous functions were unusable since I had a big red warning sign that would not go away.
I am also suffering the pangs of buying used. 5 of the 7 batteries I got are slightly puffed; to the point that it is a bit of a squeeze to get 3 of them in the compartment. They all charge up to 4.1x V, but may not be usable for long.
I also found a mystery broken component in the battery compartment and loose plugs on a circuit board at the back of the battery compartment. One plug hanging loose but I don't know if it is supposed to be plugged in or not or where. It looks like there is a suitable socket close to it.
I was able to push the other plugs in a little more but they still don't look fully seated in the sockets.
I will attach photos.
Will someone please look at the back of their battery compartment and tell me what it is supposed to look like? Are all of the plugs in the sockets? Or is this an accessory plug for something?
Also, is there a G4 camera plug somewhere in there? I have a G4 gimbal for the H920 I would like to use sometimes instead of the CGO4.
View media item 618View media item 619
PatR
Premium Pilot
The "broken, loose wire" on the left looks sorta like an antenna. It might also be something that was intentionally disconnected when converting from a base 920 to a + unit.
The second picture appears to be the battery hatch cover with the status LED. The labels are what they are. One is a standard label intended to alert the user to pay attention to their batteries, the second with the number is likely a tech identification label. The horizontal grey wire looks very much like a 2.4GHz antenna.
I would call Chris at Terrestrial Imaging tomorrow and send him the picture to review. I doubt there's anyone in the U.S. that knows the 920 better. They have my new one there now, plus a couple others, to use for comparisons.
The second picture appears to be the battery hatch cover with the status LED. The labels are what they are. One is a standard label intended to alert the user to pay attention to their batteries, the second with the number is likely a tech identification label. The horizontal grey wire looks very much like a 2.4GHz antenna.
I would call Chris at Terrestrial Imaging tomorrow and send him the picture to review. I doubt there's anyone in the U.S. that knows the 920 better. They have my new one there now, plus a couple others, to use for comparisons.
PatR
Premium Pilot
PatR
Premium Pilot
Looked at some 2.4 antennas I have laying around. The "load" cell on the wire in your picture is a little longer and the wire insulation is a different color but the cut wire is definitely an antenna that has been separated for some reason. I would not try to fly it until you have more information about why is was cut off. If your 920 has external dipole 2.4 antennas it may be they were installed during a 920 to 920+ conversion process. If so the cut antenna would have been removed from the receiver. Normally it would not be cut off though. There's usually a tiny "ring" connector on the receiver side of the antenna where separation takes place.
Saturday, I took the H920 to Frank Farray at Carolina Dronz to inspect (he is a great guy by the way, and well deserving of any business you can send his way). He also thought that the antenna found its way into the battery compartment and was in the way of loading and unloading batteries, that could have worked the thin wire until it broke. The side panel to the battery compartment is broken at the front bottom corner and will move back and forth a little; otherwise, I don't think the "load" cell could have gotten in there.
In case anyone is wondering, that disconnected plug in the photo is the retracts connector. They won't move without that connected. How do you supposed it got unplugged? The other 3 plugs in that circuit board were cocked at a 30 degree angle and partially out of the socket. I pushed them back in before the photo but was without a clue to the loose plug until I asked a Yuneec dealer.
PatR
Premium Pilot
Thanks for the plug I.D., and glad to read it’s sorted out. I think I know how it happened, prolly during conversion from 920 to 920+. That guy doesn’t work for Yuneec anymore.
I agree, Frank is a really good guy.
I agree, Frank is a really good guy.
PatR
Premium Pilot
Edward,
I've found there are multiple versions of the aircraft firmware, with at least two of them labeled as "v1.07". That should not be so. After flying my new 920+ I've found there is no voltage warning after 7-10- or even 15 minutes. The first warning occurs at 21.7v, with the battery level indicator changing color from white to yellow at the 50% point. My thoughts are there is a bug in the early 920Plus firmware when conversions were performed at distribution centers that was quietly corrected in 920's converted at the factory. Current ST-16's use the same b30 firmware as employed by the Typhoon H-480. All ST-16 firmware updates applicable to the H-480 are applicable to the 920 ST-16, providing the 920 with the same functionality as the H-480 except Team mode, which can be returned only when using a CGO-3 type camera on the 920.
I've found there are multiple versions of the aircraft firmware, with at least two of them labeled as "v1.07". That should not be so. After flying my new 920+ I've found there is no voltage warning after 7-10- or even 15 minutes. The first warning occurs at 21.7v, with the battery level indicator changing color from white to yellow at the 50% point. My thoughts are there is a bug in the early 920Plus firmware when conversions were performed at distribution centers that was quietly corrected in 920's converted at the factory. Current ST-16's use the same b30 firmware as employed by the Typhoon H-480. All ST-16 firmware updates applicable to the H-480 are applicable to the 920 ST-16, providing the 920 with the same functionality as the H-480 except Team mode, which can be returned only when using a CGO-3 type camera on the 920.
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