Battery issues and now I have the circle of death

David Wilson · Nov 16, 2016

I have been so lucky with my H and have not experienced hardly any of the issues that have come up since launch. But last night I was out flying and the first problem I had was my fully charged batteries that read 16.6 when I turn everything on immediately drop to about 15.0 when I lift up and hover. They stayed at 15.0 for quite a while before dropping and I flew about 10 minutes at close range before landing. Then as I brought it in for land the dreaded circle of death started. And it got worse the longer I fought it. Had a couple of rough landings. Just for kicks I tried a third battery and it had none of these issues during a 15 minute flight. Everything is up to date and properly calibrated. Any thoughts or suggestions?

Steve Carr · Nov 16, 2016

If you see erratic behavior again try turning off the GPS and see if it suddenly becomes stable. This assumes you are comfortable flying without GPS and understand there is no RTH or Smart Mode with the GPS off. It might be a good idea to send the flight log from that flight to Yuneec to see if they can determine what caused the problem. Generally it seems a failing GPS module or compass module is what causes the problem. You indicate you have the latest firmware on both the H and ST16. Is that correct?

Dragonflyerthom · Nov 16, 2016

You might also want to check your switches and make sure that you didn't accidentally turn the SmartMode on

PatR · Nov 16, 2016

I would like to know more related to the voltage level the batteries are regularly flown down to, switch positions selected either deliberately or accidentally by the user, and what kind of visual checks are engine listed for switch positions prior to initiating and during flight ops.

Me thinks there's much to this that has not been related.

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CraigCam · Nov 17, 2016

PatR said:
I would like to know more related to the voltage level the batteries are regularly flown down to, switch positions selected either deliberately or accidentally by the user, and what kind of visual checks are engine listed for switch positions prior to initiating and during flight ops.

Me thinks there's much to this that has not been related.

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I'd be concerned one of the cells let go. The standard stock charger does not balance well and under charges the batteries. There is no way to see individual voltage of each cell in flight and your sudden drop was from getting 1/4 less power hence all the craziness in air. I'd retire that battery straight away. It's untrust worthy. Unfortunately, we really lease our power as batteries fail after too many flights and it's a pretty unstable technology. I have thousands in unsafe puffed up batteries in all voltages and cell size from all my different multi rotors and I'm currently retiring 10 qx 350 batteries that don't have the punch anymore and pose flight risks.

BobW55 · Nov 17, 2016

David,
Did you have a chance to check the one battery in question yet?
Like Craig said, I would be curious to know if one of the cells was really off compared to the other 3.
If it appears normal, try it again (cautiously), may have to chalk it up to interference or karma.
The worse part is not knowing.

David Wilson · Nov 21, 2016

Have done some more testing over the last few days. It seems all three of my batteries do the same thing or similar. Start up at 16.6, take off and big drop to the 15.'s. Two of them level out a little better. Regardless, I have to start thinking about landing at around 14.8 - 14.6. At this point, that's 9-10 minutes of flight. Yes I can push it for a few more minutes, but I'm not wanting to push the batteries too hard. I hate to say this but with the super short flight times and mediocre camera (at best) I think I'm going to have to try something different out. The competitors are just coming out with too many nice machines with too many features and amazing cameras and they can fly close to 30 minutes per battery. I really wanted this to be my main ship but it's just not in the cards.

Dragonflyerthom · Nov 21, 2016

David I don't know for sure that you're having battery problems does Does your H have real sense and IPS? You might want to just take your typhoon H up and just let it hover taking it up to 20 feet bring it back down to 6 feet taking it back up and check time the whole flight until you get the first vibration which is your first warning. After timing you will have a better idea if you're having battery problems. If you're not getting 15 to 17 minutes call Yuneec.

PatR · Nov 21, 2016

Mine start out at 16.6 and fall to ~15.8v relatively quickly as well but the flight time is fine. Although 11-12 minutes is my typical flight with batteries under load showing 14.6v then increasing to 14.8 once the props stop I don't find that to be a problem. I view advertised flight times from any manufacturer to be the best case they ever obtained under the most perfect flight conditions and without a camera. From a consumer perspective those times are provided just to sell the product, not representing what a consumer has any chance of achieving.

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Mike Lentsch · Nov 21, 2016

Store your Lipos at between 3.8 and 3.9 volts. Don't keep them fully charged for more than a day and they'll last much, much longer.

David Wilson · Nov 22, 2016

Dragonflyerthom said:
David I don't know for sure that you're having battery problems does Does your H have real sense and IPS? You might want to just take your typhoon H up and just let it hover taking it up to 20 feet bring it back down to 6 feet taking it back up and check time the whole flight until you get the first vibration which is your first warning. After timing you will have a better idea if you're having battery problems. If you're not getting 15 to 17 minutes call Yuneec.

Thanks Dragon. One of the batteries is much worse than the others. I'm just going to retire it. The other two are getting 12 or so minutes until I'm around 14.6 so I'll just live with that for now. I just need longer flight times for what I'm doing most of the time.

David Wilson · Nov 22, 2016

Mike Lentsch said:
Store your Lipos at between 3.8 and 3.9 volts. Don't keep them fully charged for more than a day and they'll last much, much longer.

Very good point. I have definitely allowed my charged batteries to sit for more than a day as my plans to fly just don't always work out. I have hundreds of other lipos that are fine if they sit a week or less though.

BobW55 · Nov 22, 2016

David,
Only other idea I have is to fly the battery in someone else's H.
I do not know how many cycles you have on your batteries. Kind of strange the are all doing it. Using a nother H would rule out a motor or ESC on your bird going bad.

David Wilson · Nov 22, 2016

That's a good suggestion Bob, but I don't know another sole who owns a Typhoon. If I can't sell my Typhoon, and there is absolutely no interest anywhere so far, I may try one aftermarket battery and see how that goes.