Summer Heat....

[CraigCam]

I've been reading the latest threads on odd flying and batteries. One thing rarely mentioned is heat build up. Today I did back to back flights on two batteries and took them both to first warning. To say they were hot is an understatement. I got over 130 on the battery and 145 internally in the H. I did not do a third flight obviously. These screen shots are showing lower readings as the time it took to take pictures, the H cooled a bit.

 

[andrew_gotshall]

What was the temperature for the day you flew? I've noticed that if I'm flying in the direct sun the top will be warm to the touch.

 

[JulesTEO]

Never actually measured the temperature, but I'd like to know if it's been determined how hot its too hot for these particular components.

Perhaps more experienced users (people with DIY experience, more familiar with the actual internal electronics) can give a bit of insight.

I know different components can run at various temperatures (for example, cheaper devices might get damaged at 60ºC (140) while the CPU in my laptop has a Max. operating temperature of 100ºC (212F) before automatic shutdown to prevent damage)

Also, I just recently started researching about heat in Lipo's, but what I read in a few sites was "If you can't hold the battery in your hand, its too hot!". Which is absolutely subjective, and doesn't help too much.

A weird question that comes to my mind is: Obviously a hotter environment will make the aircraft run hotter just for being exposed to it, but, Does flying on hotter, less dense air, means the motors have to work harder to produce lift, drawing more energy, reducing battery life and increasing heat produced by the battery?

 

[CraigCam]

What was the temperature for the day you flew? I've noticed that if I'm flying in the direct sun the top will be warm to the touch.

It was just getting into the low nineties. It's hot early and fast here and I was hovering in direct light for over 12 minutes. I do not ever try flying here during the mid day hours in the summer as I know what can happen to mechanical things on our crazy heat. I had to install a cooling fan in my Chroma back in the day and I still damaged a mother board from over heating.

The TH board crams a lot of surface mount components in a tight area including the ESCs. It generates a lot of self heat and sits over the hot battery. For sure there is an over heat fail point that some may have already experienced in their mystery fly away or crash.I don't know what that is nor was I looking to find it. I was just flying low and slow to use up power and discharge these two batteries.

I did however get an unusual warning about exceeding 8000' on the second battery that I've never seen before. That's what got me thinking that me flying back to back batteries is unwise in this heat. I brought it back closer to myself post that weird warning and hovered out the rest of the flight. Once landed, the battery was almost hand burning for me and I'm an ex plumber with high tolerance for hot surfaces.

So now I'm discharging what I have not flown recently in the safety of the cooler indoors. Everyday, another lesson and a wiser owner. Safe flying to all.

 

[Murray Martz]

I've been reading the latest threads on odd flying and batteries. One thing rarely mentioned is heat build up. Today I did back to back flights on two batteries and took them both to first warning. To say they were hot is an understatement. I got over 130 on the battery and 145 internally in the H. I did not do a third flight obviously. These screen shots are showing lower readings as the time it took to take pictures, the H cooled a bit. View attachment 6650View attachment 6651

Long time no hear, and holy crap that is hot!

 

[PatR]

I would not put too much faith in operations above 60C. I can only relate something gleaned from experience, but I think it's relevant. I can't specify what they were but the Iraq summers get pretty **** hot. 120-130F, in the shade. Some aircraft were experiencing electrical system shut downs after sitting too long on a black asphalt taxiway. Turns out the heat being reflected from the taxiway was more than some different components could handle and the aircraft ended up being towed back to the ramp. Some pretty high end hobby grade equipment experienced the same problems. Bear in mind I'm referencing Milspec equipment for the expensive iron, not hobby grade components of unknown quality having no certification standards.

As for seeing an 8000' warning on a hot day, that's pretty easy to do when a barometer is being used to estimate altitude. As we all know, pressure decreases as altitude increases, and an increase in temperature cause atmospheric density to decrease. A "Standard Day" is formulated upon a temp of 59*F, zero humidity, and a "sea level" pressure of 29.92inHg. Any addition of temperature or humidity acts to reduce the pressure, effectively increasing the density altitude.

Jules, the answer to your question is; Yes, the motors and propellers have to work harder to generate the same amount of lift at 100* as it would normally do at 50*. Being fixed pitch, the propellers have to turn faster to generate the same amount of thrust in a less dense atmosphere.

 

[Timothy Reece]

Never actually measured the temperature, but I'd like to know if it's been determined how hot its too hot for these particular components.

Perhaps more experienced users (people with DIY experience, more familiar with the actual internal electronics) can give a bit of insight.

I know different components can run at various temperatures (for example, cheaper devices might get damaged at 60ºC (140) while the CPU in my laptop has a Max. operating temperature of 100ºC (212F) before automatic shutdown to prevent damage)

Also, I just recently started researching about heat in Lipo's, but what I read in a few sites was "If you can't hold the battery in your hand, its too hot!". Which is absolutely subjective, and doesn't help too much.

A weird question that comes to my mind is: Obviously a hotter environment will make the aircraft run hotter just for being exposed to it, but, Does flying on hotter, less dense air, means the motors have to work harder to produce lift, drawing more energy, reducing battery life and increasing heat produced by the battery?

I live in Phoenix and if it is over 95 Fahrenheit I do not fly. Figure if it's say a 100 that's the air that is cooling your motors and Electronics in your bird

 

[Shadowolf]

If I Don't fly in temps over 90 there goes 1/4 of my work availability.

 

[FlushVision]

Fortunately, here in the North of England, the outside temperature seldom gets above 80*F and a rare occurrence in deed if it gets close to 90*F. So, for me, not being used to warm weather is my limiting factor...not what my aircraft can stand. For me, then, I'm more concerned with how my TH can cope in low temperatures than high temps. So, I will tend not to fly if the outside temperature is much more than the mid 70s but that has nothing to do with what the TH can handle. It's what I can handle.

 

[Gracilsinfor]

Hi from Portugal.
i have flown my TH with 35 C conditions, and even a bit more, without any problems, of course heating was quite notable afterwards, but not as much for the battery as for the cannopy.
having said that, I avoid as much as possible flying in peaks of sunny days even in winter time.
nevertheless, two remarks can be made about this question. being the first that temperature at ground level is always higher then in altitude and the second that yuneec fail to adress design concerns properlly regarding the color choose, perhaps trying to detach from dji inspire decided for a drone all in black. radiation is much more a ***** then irradiation, and they should have noticed.
covering the top side of the cannopy with some white sticker for light reflection purpose might improve heat absortion but don't know to which extents it would hinder gps or mess up radio signals, or even compromise the heat dissipation from the inside. it would be better if yuneec or a third part, provide a white cannopy for replacement.
btw, hope that orange be a better choice :/

 

[AH-1G]

Drill a small hole on top of the H and install a mini umbrella. If not wrap your H in foil. Just kidding. However a properly designed apparatus mounted on top of the H (a gap between the body and apparatus) would limit the amount of heat from the sun.

 

[Gracilsinfor]

Drill a small hole on top of the H and install a mini umbrella. If not wrap your H in foil. Just kidding. However a properly designed apparatus mounted on top of the H (a gap between the body and apparatus) would limit the amount of heat from the sun.

add a slice of lime and a straw and we got the TH Daikiri

Daiquiri