Safe temperature to fly your drone?

[Xitor]

Hi, looking through the forums, I see the recommended max operating temp is 104 degree (40C). I also see folks reporting battery temps over 150f when flying in air temps well below that (e.g. 90F). Living in Texas, I'm wondering what other DJI owners use a real life temperature margin to protect the life of the drone and battery.

 

[FLDave]

I generally wouldn't fly much over 90F in FL as it's too hot for me. My Air 2s battery reached 130F on a sunny day in April; this was the second immediate flight on the battery. Battery temp was reported by AirData from the flight log. Local air temperature 88F.

 

[MAvic_South_Oz]

You are going to shorten the life of your batteries getting them that hot regularly.
Around 87c / 120f is normal mid range safe battery temp in flight.

Above this, it's moving to 'It's Cooking' I think on the Airdata info, (or is it in the flight info somewhere ?).
I think 66c / 150f would be getting into this region.

Make shorter flights perhaps, and land at 50% battery, you can then just place the battery in storage at normal discharged level and not stress it that way at least.
I'd also put it somewhere really cool on landing, not in a hot car / bag, in the shade somewhere airy, to cool.
A small insulated cooler on site might be good to store batteries in really hot weather, both before and after flight.

I'd be careful with some drones, the mini 3 pro for example seems to be getting hot in some cases.

I usually fly when it's comfortable, and I usually walk to a lot of places to fly.
So my general rule of thumb is max 35c / 95f, and that would be close by.

 

[FLDave]

Where did you find battery temperature specification data for DJI batteries?

 

[MAvic_South_Oz]

Where did you find battery temperature specification data for DJI batteries?

My post ?
I recall seeing photos of this somewhere, could have been here on this forum.
It's either airdata, or buried in the Go4 or Fly app, possibly airdata full account info ?

I'll have a little dig around . . .

Ok, here ya go, happens to be an Air 2 thread also.

Mavic Air 2 Battery Temperature Survey

The battery temp in the AIR 2 manual states the charging temp: 41 to 104F, 5 to 40C. What was the max temperature you've recorded on your flight data? A rare warm day here in the northeast, I recorded 119.3F. Looking to see other's flight data. I think it's okay, but being the newest drone in...

mavicpilots.com

 

[FLDave]

My post ?
I recall seeing photos of this somewhere, could have been here on this forum.
It's either airdata, or buried in the Go4 or Fly app, possibly airdata full account info ?

I'll have a little dig around . . .

Ok, here ya go, happens to be an Air 2 thread also.

Mavic Air 2 Battery Temperature Survey

The battery temp in the AIR 2 manual states the charging temp: 41 to 104F, 5 to 40C. What was the max temperature you've recorded on your flight data? A rare warm day here in the northeast, I recorded 119.3F. Looking to see other's flight data. I think it's okay, but being the newest drone in...

mavicpilots.com

So the data is maximum charging temperature not maximum flight temperature. Very different.

 

[FLDave]

The Air 2s lists maximum ambient temperature for flying as 104F one would expect the max battery temperature to be much higher as the battery does not have any special internal air cooling. I expect the DJI has done testing to determine safe ambient temperatures with their batteries.
What might be most helpful would be to monitor battery temperatures even if it's after every flight. You can then compare battery temperature to ambient temperature and flight conditions. AirData provides battery data you can view in your txt flight log.

 

[MAvic_South_Oz]

So the data is maximum charging temperature not maximum flight temperature. Very different.

No, that thread OP merely stated that recommended ambient charging temps are such and such.
The report temp there would be flight temp.

 

[FLDave]

The Air 2s states the operating temperature of 32 to 104F for the aircraft.
It also state the charging temperature for the battery as 32 to 104F.
I believe that relates to the ambient temperature in both cases, not the actual battery temperature.
Of course there is a temperature of the battery (not specified) where charging would be unsafe. Since the battery has internal measurements I assume it would not charge when the battery temperature is too high. It's always advisable to allow after-flight batteries to cool before charging. I never tried charging a hot battery.

 

[Dave Maine]

The batteries for both the MA, Phantom 4adv, and P3 4K will refuse to charge when they are too hot.

 

[Xitor]

No, that thread OP merely stated that recommended ambient charging temps are such and such.
The report temp there would be flight temp.

The 104F was the number that came up everywhere (DJI and other sites including this one) when initially searching before posting. Both as operating temp range, as as posted in the manual below. However, when researching that and seeing people get battery numbers as high as 150 or even one person reported 188, when flying below that temperature, I was looking for more guidance. Yes I'm concerned about battery life, but more importantly catastrophic failure.

Drone operating temperature - Page 57



Remote Controller operating temperature - page 53


Battery temperature - page 27:


Also, Droneblog and another site, both listed this:

• If an intelligent flight battery reaches a temperature of 158° F (70° C) it will be at high risk of combustion or explosion.

Just checked my flight logs and I have a couple flights where the battery hit 130F, but in both cases the outside temp was around 90F.

 

[MAvic_South_Oz]

Drone operating temperature - Page 57

Remote Controller operating temperature - page 53

Battery temperature - page 27:

Yes, these are commonly listed for all DJI model drones and batteries, and usually very similar as they are standard lipo general safe ambient temp, and charging temp (what the ambient temp is for that purpose).

There is usually nothing about how hot a battery should be allowed to get during flight, which is obviously going to be higher, and sometimes considerably higher.

That blog info was interesting.

Also, Droneblog and another site, both listed this:

• If an intelligent flight battery reaches a temperature of 158° F (70° C) it will be at high risk of combustion or explosion.

Just checked my flight logs and I have a couple flights where the battery hit 130F, but in both cases the outside temp was around 90F.

It seems your flights are probably in the ok range for battery temps, and the Air2s might be better at handing that than some drones with no cooling fan, or simply hotter operation.

It would be interesting for new Mini 3 Pro owners with airdata to see what they commonly get for battery flight temps.

edit - typo

 

[R.Cowan]

Hi, looking through the forums, I see the recommended max operating temp is 104 degree (40C). I also see folks reporting battery temps over 150f when flying in air temps well below that. Living in Texas, I'm wondering what other DJI owners use a real life temperature margin to protect the life of the drone and battery.

I live just south of Houston and also wondering what is a safe temperature. I had mine in the air yesterday for about 30 minutes. Outside temperature was 98. It performed flawlessly, however when I brought it down and went to fold the arms, I grabbed one of the motors and it was so hot to the touch, I was concerned that may cause damage. I pulled the battery and while it was hot, it didn't seem unusually hot considering the conditions. So I'm also curious who out there might share information on what is a "real" safe temperature.

 

[FLDave]

I believe the actual battery flight temperature is available in the .txt log file if you want to know.
Actually, it's good to know someone has real world information for flying at 98F. In FL I think my body would object high temperature before my Air 2s.

 

[Xitor]

I live just south of Houston and also wondering what is a safe temperature. I had mine in the air yesterday for about 30 minutes. Outside temperature was 98. It performed flawlessly, however when I brought it down and went to fold the arms, I grabbed one of the motors and it was so hot to the touch, I was concerned that may cause damage. I pulled the battery and while it was hot, it didn't seem unusually hot considering the conditions. So I'm also curious who out there might share information on what is a "real" safe temperature.

Would be very interested in your battery temp too from the flight log. I had to find the location of the log files and upload to airdata.com. About 30 minutes between Googling and execution, but then had a good way to pull battery Temps from flights.

 

[MAvic_South_Oz]

I live just south of Houston and also wondering what is a safe temperature. I had mine in the air yesterday for about 30 minutes. Outside temperature was 98. It performed flawlessly, however when I brought it down and went to fold the arms, I grabbed one of the motors and it was so hot to the touch, I was concerned that may cause damage. I pulled the battery and while it was hot, it didn't seem unusually hot considering the conditions. So I'm also curious who out there might share information on what is a "real" safe temperature.

Just that motor that seems to be running hot ?
If so, it sounds like that motor MIGHT have an issue.

Maybe check after each flight a few times with a laser type temperature reader, gather some data, and if there is a particular motor getting much hotter than the others, open up a ticket with DJI to address this.

 

[R.Cowan]

Just that motor that seems to be running hot ?
If so, it sounds like that motor MIGHT have an issue.

Maybe check after each flight a few times with a laser type temperature reader, gather some data, and if there is a particular motor getting much hotter than the others, open up a ticket with DJI to address this.

As ridiculous as it might sound, I really didn't check the others. I just assumed it was hot due to the ambient temperatures and the others would be the same. Thanks for the suggestion, I will be sure to check them all on my next flight.

 

[karlblessing]

Just keep in mind, don't be quick to start charging your spent batteries until they've cooled down a little bit. Likewise, don't be quick to pop in your freshly charged batteries right after they've been charged.

But I concur that if DJI rates the ambient operating condition as 32-104F it's probably best not to fly in weather that has hit 100F+ (though I'm pretty sure nearly all of us has flown below 32F regardless).

 

[R.Cowan]

Just keep in mind, don't be quick to start charging your spent batteries until they've cooled down a little bit. Likewise, don't be quick to pop in your freshly charged batteries right after they've been charged.

But I concur that if DJI rates the ambient operating condition as 32-104F it's probably best not to fly in weather that has hit 100F+ (though I'm pretty sure nearly all of us has flown below 32F regardless).

Thanks for the advice. I'm usually pretty conscious of the battery temps and try to take good care of them.

 

[dodgerr]

I would second what karlblessing says about letting warm batteries cool before recharging.

What increases internal lithium battery temperatures is prolonged periods of high amp draw, especially with lithium batteries with a low "C" rating, which is the maximum discharge rate before damaging cells. I have never seen a published "C" rating on any DJI batteries but from my experience with Mavic, Phantom, and Inspire DJI batteries, they are all very high quality lithium cells and are probably above 40 or 50C. Just guessing.

Oscar Liang has a short article about understanding what "C" rating is and how internal resistance is what warms up batteries:

What is C Rating of LiPo Battery FPV Drones - Oscar Liang

C rating is one of the most important factors to consider when buying LiPo batteries. In this tutorial we will explain what C rating is and how it's calculated.

oscarliang.com

You may notice that when trying to increase flight times while designing a new version of the Mavic, from the original Mavic to the Mavic 2, for example, DJI went from 3 cell(11.4v) to 4 cell(15.4v) while keeping about the same size cells, 3830 mAh to 3850 mAh. Why did they not just increase the size of the cells? Because by increasing voltage (and reducing motor kv ratings) they could avoid higher amp draw and in turn higher battery heating rates. This is why rc airplane and drone racers use the highest voltage (number of cells) batteries they can to keep amp draw and battery heat down as much as possible.


A couple of examples of how to quickly heat up your batteries? Taking off and flying full power up to 400'..... or..... Flying full power into high winds aloft, especially when horizontal speeds seem abnormally low.
If you want to really bake your battery quickly, take off at full ascending power and push full forward and straight into high winds.

If you must fly in higher outdoor temperatures, and even when flying in lower outdoor temperatures, just try to lay off the power setting, take shorter flights like MAvic_South_Oz says, and keep an eye on your battery temps.