Low Battery Warning and Erratic Flight

[BeeRAD56]

I'll start by saying I'm a Newbie. I have a 12 successful flights on my Typhoon H Pro and have a LOT to learn.

I'm starting to notice erratic flight behavior when I reach the first low battery warning. Once while landing under low battery the bird would not descend below approximately 30 feet. I should also note that I hadn't yet put the gear down. I raised it up to about 50 feet, dropped the gear and landed safely.

Yesterday while landing in dead calm conditions, under the first low battery warning, the bird was drifting all over the place making it hard to control and difficult to land safely.

I compared these experiences to a recent flight where the wind came up suddenly early in the flight. Not being comfortable with my skills in the wind yet, I headed for home with lots of battery left. The bird was rock solid during decent automatically reacting and pitching into a 15 knot wind gusting to 20 and the landing was a piece of cake.

All that said, does the unit become glitchy during low battery warnings? Or were these experiences just random chance?

Also, I generally get the first low battery warning at 14.3 volts in that helps.

Thanks in advance!

 

[prathbun]

After 8-plus hours on my H (~30 flights) I've never had it get glitchy at the 14.3-volt warning. The only glitchiness I've had to deal with is the over-agressive GPS control at low speeds.
Yes, 14.3 volts is the first low-battery threshold, and in my experience there's still a good deal of juice left after that; you just want to stay close and slow...
The H doesn't know whether the gear is up or down, so there's no issue there.

My first controller had an issue with the flight-mode switch; are you sure it's not slipping in and out of safe mode?

 

[mcbutler]

Best not to run into low battery warning at all.
It is only there to remind you of something that you should be watching closely in order to prevent it happening.

May well be linked, I have heard it reduces power to a couple of motors once battery warning comes up to extend its duration so you can get it home.

Sure someone on here can confirm or deny that??

 

[CC Rider]

My two cents worth: I've been flying my Typhoon routinely for over 2 months and have often gone well beyond the first low battery warning without any noticeable change in its performance whatsoever. As far as it not descending below 30' that had nothing to do with the H's normal operation. I believe if the landing gear is up the Typhoon won't allow you to descend lower than about 12' so as not to crash it. But not at 30'.Also, what flight mode were you in when this happened to you and were your front sensors engaged at the time?

You may want to consider recalibrating everything, compass, etc. (not the camera settings, though) and making sure you are on a totally level, flat surface when you calibrate the accelerometers. Remove the camera mount, too, when you do your compass calibration as the metal and motor magnets in that assembly can mess up your calibrations, as can cell phones, metal, etc. I even remove my belt so that the buckle doesn't factor into it and make sure I am away from large structures, concrete, etc., all the stuff Yuneec tells you to avoid.

I don't think you have a major problem on your hands or a defective bird, either. Most of the time there is an answer to a problem such as this. And the Typhoon should be rock solid even in 15-20 mph winds easily. It's a very stable machine and a great choice of drones to purchase.

As far as the Typhoon reducing power to 2 motors during low battery status, I've never heard of that before (not saying I know it all, either) but my common sense tells me that they wouldn't design a flying machine to intentionally lose power to 2 of its 6 motors needed to stay in stable flight. In fact, I would think their design would be just the opposite:to design it such as to ensure proper control and performance of the aircraft until the last drop of power is gone.

However, poster mcbutler is very correct about not intentionally flying until you get the first low battery warning. As he stressed, that is just a warning; keeping your eye on the battery level and bringing the bird back before the warning is a good habit to get into. It will surely help you avoid a last minute power-failure crash and will greatly extend the life and performance of your batteries, which are costly. LiPo batteries are very particular, and not draining them or pushing them to their limit should be avoided.

I'm sure other folks who know more than I do will chime in with their thoughts. Good luck!


'

 

[FlushVision]

Just be on the ground before the first warning. Simples.

I've only ever once gone beyond the first warning. Indeed on that same flight I even reached the second warning and finished up with a rather bouncy undignified landing. No damage, but undignified.

 

[PatR]

A word of advice. If you don't want to buy new batteries all the time, land before you get a low volt warning.


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[Rayray]

Once while landing under low battery the bird would not descend below approximately 30 feet.

All that said, does the unit become glitchy during low battery warnings?

Your first situation is not normal in Angle mode. If this repeats call Yuneec. You cannot fix this, although it is not logical. Perhaps you inadvertently caused it.

Low battery has nothing to do with TH behavior, but you need to watch the battery and be close to landing about the time of first warning, at 14.3. Yuneec says nothing wrong with running to 14.3 (which unloaded becomes 14.5 or so). I have one Yuneec battery with over 100 flights that shows no degradation.

The TH is indeed sensitive to small right stick movements trying to land. Take your time, in Turtle mode, and practice nudging the stick to position it for landing. Remember to turn off OA before landing (and don't turn it on till in the air).

 

[PatR]

Ray,

For general informational purposes, battery voltage should be measured for useful voltage when under load. The no load, or light load, voltage levels should not be used to gauge battery health/level. Nominal voltage for a lipo cell is 3.7 volts. Over the years it's been pretty well established that use with per cell voltages less than 3.4v/cell is not conducive to long battery life, and voltage levels from 3.2v/cell and lower can generate unrecoverable cell damage. Personally, I prefer to remain at or very close to cell nominal voltage, or 14.8v, as the point where I'm starting my landing.

 

[Drone On]

I had the same issues with my H when i first got it. I only did 2 flights and on both flights it seemed when the battery started getting low, after about 10-12 mins of flight, well before the low battery warning. I would start getting GPS warnings, compass warnings and the H started flying erratically and difficult to control. It also took several attemps to get it to land. It would get down to approx 15 feet and stop, the landing gear was down and obstacle avoidance was off. After climbing and descending a couple of times it would land and then try to flip it self over on the ground. After those 2 flights I sent it in to Yuneec to be tested.
They replaced the GPS & Compass module and the upper cover with the square antenna in it. They put it through a 26 step test flight and sent it back to me. I have since flown 4 batteries and it has been rock solid, even in gusty winds, and I haven't had one GPS or compass warning. It flies, lands and returns to home flawlessly so far. I am very satisfied. If you have done all the calibrations correctly and you still have problems, before you crash it, call Yuneec, get an RMA #, put a letter in the box explaining all the issues you have and send it in...That's what I did and I am one happy H pilot now

 

[Rayray]

Over the years it's been pretty well established that use with per cell voltages less than 3.4v/cell is not conducive to long battery life, and voltage levels from 3.2v/cell and lower can generate unrecoverable cell damage. Personally, I prefer to remain at or very close to cell nominal voltage, or 14.8v, as the point where I'm starting my landing.

3.4 per cell is 13.6 if my math is correct, far below the 14.3 1st warning. If you choose to land at 14.8, you certainly have no objections on my part.

 

[BeeRAD56]

Thanks to all for your responses and help with this issue.

I have been routinely running the battery down to 14.3v thinking that was best for the battery to not develop a short term memory (like me). I realize now that has been incorrect and will now start landing well before the low battery warning and see if the erratic behavior continues.

As a raw beginner, I've assumed that the strange and inconsistent behavior has been something I've been doing wrong. With the input I've received here, along with gaining more experience, I'm sure I'll be able to pin point the issue.

Thanks again to everyone for the great input and your time!

 

[PatR]

3.4 per cell is 13.6 if my math is correct, far below the 14.3 1st warning. If you choose to land at 14.8, you certainly have no objections on my part.

Ray,

My post was for general informational purposes, not judgmental. What people do with it is up to them.

Something that may assist the OP, li-po's do not develop "memories". That's associated more with NiCd's and to a lesser extent NiMh chemistries.


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[BeeRAD56]

Battery management update:

I spoke to Support at Yuneec today and was told that to limit your battery to 14.8v will damage the battery over time and it WILL if fact develop a short term memory. I was told that it's best to run it down as close as possible to 14.3v to maximize the full capacity of the battery over time. Support also said that there is no issue with operation into the 1st warning but to land quickly thereafter.

Just wanted to share since this perspective from Yuneec Support is in conflict with what a number of members have said.

 

[PatR]

Now call back three more times, ask the same question of three more different techs, and see what you come up with. After all that Google up some battery web sites and dig in for an education.


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[BeeRAD56]

Now call back three more times, ask the same question of three more different techs, and see what you come up with. After all that Google up some battery web sites and dig in for an education.


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Thanks, I get all that. I also get that limiting the battery to 14.8v gives me a 10 fight time from my testing yesterday. I can't image that a 10 minute flight time was Yuneec's intent or maybe it is and they hope to sell lots of batteries.

 

[PatR]

I did not say that anyone needed to limit the battery to 14.8v. Please go back and read my post where I referenced 14.8v again for clarity. I said that's what I do. BTW, with relatively normal flying that will provide 12 to 14 minutes of flight time. I will say this as a statement of fact, those that use more than 70% of battery capacity will end up buying more batteries over time than those that don't. Use MA as the baseline for measurement. This is the area that causes contention around Yuneec batteries. We do not know what their capacity truly is, but there is string suspicion they are not 5400ma batteries.




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[ChuckBridges]

A string suspicion... sound pretty thin. Sorry, tried to resist, couldn't.

 

[K2BLS]

Best not to run into low battery warning at all.
It is only there to remind you of something that you should be watching closely in order to prevent it happening.

May well be linked, I have heard it reduces power to a couple of motors once battery warning comes up to extend its duration so you can get it home.

Sure someone on here can confirm or deny that??

The problems I've had all occurred after the first low battery warning. Now, I always plan on landing before that happens. No problems since. So far....

 

[Jester]

This is the second or third topic where I have seen someone newer, (like myself) ask a question and get a ton of advice that is totally inconsistent and makes a new person feel very frustrated, with Yuneec seeming to be the problem, due to their own videos giving bad advice. If you look in the help section where their videos are, there is a video about battery management, and the guy literally says, when you get that first low battery warning to bring the H back in closer to yourself. Nothing mentioned about that being the lowest you should ever get it, or that you should never let it even get to the 14.3, like all of you real world flyers that seem to know more about batteries than the people that supplied them to us with our TH's.
PatR, that conversation we had a couple weeks ago on the hand catching, where I said that myself and several new guys like me, tried to go out and watched all the videos we could before taking to the skies foolishly, I didn't give a good example that day, but this and the videos like the hand catching are the examples I was trying to remember that day, but couldn't get my mind to cooperate.
My point is, after seeing their products in the hands of very experienced people that have been using batteries and UAV's, and in real world environments, Yuneec really needs to comb through and remove their bad advice videos, or correct them to the truth. I remember an older video on firmware updates that was missing important info, and another on calibrations that left out important info, as well.
It does make some of us come strolling in here, looking like we're fools that didn't do our homework, but unfortunately, the maker of our own product is the cause of it in many cases.
To the OP, I'm curious what the battery level was on your ST-16 when you had these issues because I once, (on my second flight ever) lost control of mine when the ST-16 battery got down to 77-78%. Luckily, I had just read somewhere that someone else had that problem when they were below 80%, but was so concerned with learning the H, and overwhelmed with all the new info I had studied that I forgot until it happened, but I had to run into my garage and plug in the ST-16 to regain control and bring it in. Thankfully I was right in my back yard and still had line of sight between the ST-16 and the H when I plugged it in, and it immediately regained control. I decided to not let it go below 80% ever again, but then had it start to exhibit the same but more mellow behavior at 82% recently as I was about to land anyways. I emailed Yuneec about it, but they never answered me so I need to call them.
Not sure if that was your case or not, but I'd be interested to know if anyone else has had the problem.

 

[K2BLS]

This is the second or third topic where I have seen someone newer, (like myself) ask a question and get a ton of advice that is totally inconsistent and makes a new person feel very frustrated, with Yuneec seeming to be the problem, due to their own videos giving bad advice. If you look in the help section where their videos are, there is a video about battery management, and the guy literally says, when you get that first low battery warning to bring the H back in closer to yourself. Nothing mentioned about that being the lowest you should ever get it, or that you should never let it even get to the 14.3, like all of you real world flyers that seem to know more about batteries than the people that supplied them to us with our TH's.
PatR, that conversation we had a couple weeks ago on the hand catching, where I said that myself and several new guys like me, tried to go out and watched all the videos we could before taking to the skies foolishly, I didn't give a good example that day, but this and the videos like the hand catching are the examples I was trying to remember that day, but couldn't get my mind to cooperate.
My point is, after seeing their products in the hands of very experienced people that have been using batteries and UAV's, and in real world environments, Yuneec really needs to comb through and remove their bad advice videos, or correct them to the truth. I remember an older video on firmware updates that was missing important info, and another on calibrations that left out important info, as well.
It does make some of us come strolling in here, looking like we're fools that didn't do our homework, but unfortunately, the maker of our own product is the cause of it in many cases.
To the OP, I'm curious what the battery level was on your ST-16 when you had these issues because I once, (on my second flight ever) lost control of mine when the ST-16 battery got down to 77-78%. Luckily, I had just read somewhere that someone else had that problem when they were below 80%, but was so concerned with learning the H, and overwhelmed with all the new info I had studied that I forgot until it happened, but I had to run into my garage and plug in the ST-16 to regain control and bring it in. Thankfully I was right in my back yard and still had line of sight between the ST-16 and the H when I plugged it in, and it immediately regained control. I decided to not let it go below 80% ever again, but then had it start to exhibit the same but more mellow behavior at 82% recently as I was about to land anyways. I emailed Yuneec about it, but they never answered me so I need to call them.
Not sure if that was your case or not, but I'd be interested to know if anyone else has had the problem.

Personally, I have not let mine run down below 80%, but at that level, no problems. It's only the H that I've ever had a problem with running the battery too low (below 14.3). I always try to land before the first low battery warning.