Hello all,

Just had a flight in 90 degree weather and after about 15 minutes of flight, (light maneuvers: Active track at slow speed followed by hovering at 100 feet in 14 mph gusts), I landed with a battery temperature of 56 degrees Celsius. My question is, is this safe operating temperatures and if it is, is it healthy for the battery? I dont plan to fly too often in the intense heat of the day, prefering evening or early morning instead, but I thought I would bring it up to see what these temperatures do to these batteries.

Alpha

I am wondering the same. Everytime I switch batteries, I feel the battery is extremely hot, even though the wheather temperatures aren't too high. (like 25°C)
But I can barely touch the batteries because they are so hot. (Didn't check the temperature of them, yet)

saviour Posted at 2018-6-20 21:25
I am wondering the same. Everytime I switch batteries, I feel the battery is extremely hot, even though the wheather temperatures aren't too high. (like 25°C)
But I can barely touch the batteries because they are so hot. (Didn't check the temperature of them, yet)

Yeah, I know. Having worked with metal in a shop, I can normally grab stuff thats about the same temperature or higher no problem. That being said, the heat coming of these are crazy since I dont expect them to be this hot.

I am working in chemistry so I know temperatures aswell. Feels like at least 50°C after a flight. I will check the temperatures next time I land with an empty battery.
It's a bit worrying to see the battery having such high temperatures even though it's not even a hot sommer yet.

Actually the CPU placed above the battery are hotter. Battery is hot on the top and button is on. I fly 13 minuets in 30 degrees C and the battery temperature is close to 60 C after landed. I do worry this situation and stop flying on or above 30 C. Also let the aircraft cool down around 20 minuets before next flight.

GDL Posted at 2018-6-20 23:10
Actually the CPU placed above the battery are hotter. Battery is hot on the top and button is on. I fly 13 minuets in 30 degrees C and the battery temperature is close to 60 C after landed. I do worry this situation and stop flying on or above 30 C. Also let the aircraft cool down around 20 minuets before next flight.

Interesting, did not know that. I was fortunate to have completed all of the tests and shoots when the temperature hit 56 and the battery just entered low power warning. The strange thing I have noted is that my spark doesnt seem to have the same issue, possibly because the batteries cross section is larger and more exposed to nearby air movements. Honestly, this is only speculation that will need time out in the field to prove one way or another, and I plan on testing over the next few days.

It doesn't matter the CPU is hotter because that's not a problem as in PCs e.g. CPUs are used up to 70 or 80°C. Yeah, the battery is extremely hot on the bottom. (or top if it's attached to the drone)
I also wonder if you should let the drone on for a while after landing so the cooler above the CPU works a bit and cools it down, too. But as I stated the CPU shouldn't be a problem. CPUs nowadays last for so long but batteries on the other hand don't and I'd also like to know if you should cool them down manually maybe or just store them in the bag in a hot state.

Not really hot in the Netherlands for a daily basis, but I have been flying some days at 30 degrees and not precisely at slow pace. After returning the drone the battery was  of course hot, but it was never hot enough to burn my hand or feel unsafe to put in the bag.

I'll take another look on a different day, but so far I haven't felt any danger like OP is  explaining.

The batteries do cool very quickly after use. Be sure that they reach room temperature before recharging but I wouldn't worry about how hot they get. DJI have also advised on numerous occasions that you do not need to wait for the drone to cool between flights though best not to fly in temperatures exceeding 40c.

I live in the tropics and batteries generally hit 56-59c on every single flight.  
2 out of my 3 have swollen after 12 months use (roughly 60 charges each).
The only issue i notice is it takes a while to cool before charging - up to 45 mins which means i cant quickly recharge and reuse on site.

I live in Arizona, and fly at temperatures over 100 degrees, never had an issue.

gnirtS Posted at 2018-6-21 00:44
I live in the tropics and batteries generally hit 56-59c on every single flight.  
2 out of my 3 have swollen after 12 months use (roughly 60 charges each).
The only issue i notice is it takes a while to cool before charging - up to 45 mins which means i cant quickly recharge and reuse on site.

The Mavic Pro batteries did take longer to cool than the Air batteries, that's true.

saviour Posted at 2018-6-20 23:52
It doesn't matter the CPU is hotter because that's not a problem as in PCs e.g. CPUs are used up to 70 or 80°C. Yeah, the battery is extremely hot on the bottom. (or top if it's attached to the drone)
I also wonder if you should let the drone on for a while after landing so the cooler above the CPU works a bit and cools it down, too. But as I stated the CPU shouldn't be a problem. CPUs nowadays last for so long but batteries on the other hand don't and I'd also like to know if you should cool them down manually maybe or just store them in the bag in a hot state.

I have noticed that when idling after landing the tempeture drops anywhere from .1-.7 degrees celsius per second. this might also be cause of the shade i was in but even then it wasnt that cold in the shade

DJI batteries should not feel hot, they will feel warm when depleted after flying if you have flown very aggressively in Sport mode, warm/very warm to the hand touch is normal under those flying conditions. Lipos heat up depending on the amps drawn during flight, if I remember correctly I thinks most DJI ESC's draw 14-15 amps under normal conditions, if you work it hard they will heat up more. I fly 3S and 4S batteries in my race quads with 50 amp ESC's, after an aggressive run they get very warm but not to the point where you can not hold them.

QuadKid Posted at 2018-6-24 12:42
DJI batteries should not feel hot, they will feel warm when depleted after flying if you have flown very aggressively in Sport mode, warm/very warm to the hand touch is normal under those flying conditions. Lipos heat up depending on the amps drawn during flight, if I remember correctly I thinks most DJI ESC's draw 14-15 amps under normal conditions, if you work it hard they will heat up more. I fly 3S and 4S batteries in my race quads with 50 amp ESC's, after an aggressive run they get very warm but not to the point where you can not hold them.

The thing is though, i wasnt even flying that aggressively. As i mentioned, i was flying wit hmm activetrack at 2.2 mph speed priority followed by a climb to 150 feet to hover for 12 minutes for some timelapse. That shouldnt make the batteries increase to 56 degrees unless its the ambient air temperature

AlphaFlightNW Posted at 2018-6-24 13:03
The thing is though, i wasnt even flying that aggressively. As i mentioned, i was flying wit hmm activetrack at 2.2 mph speed priority followed by a climb to 150 feet to hover for 12 minutes for some timelapse. That shouldnt make the batteries increase to 56 degrees unless its the ambient air temperature

I agree 56C is warmer than it should be even running in sport mode, how many charges have you run through them? Are all you batteries doing the same thing?

QuadKid Posted at 2018-6-24 13:14
I agree 56C is warmer than it should be even running in sport mode, how many charges have you run through them? Are all you batteries doing the same thing?

about 30 or so cycles on each, I have only had the drone since early april. As far as the temperurate for all of them, 2 of them get to about 53 degree average after 16 minutes of flight in approx 70 degree weather. That being said, I have also been testing my spark and its battery never reaches above 50 degrees celsius, even in sports, which could lead me to two conclusions. The first, and obvious one, is that flight time has a linear relation to battery temperature, with a tolerance to consider ambient air temperature and method of flying. Secondly, and the less likely option, is that somehow the mavic is not dissipating heat fast enough unlike the spark. Honestly, I am not sure and I will have to wait a few hours to test this theory as it is about 90ish degrees out and I am not comfortable flying in these conditions with the mavic. if it helps any, my mavic is black which could explain a small percentage of the heat absorbtion

Just for comparison I fly my MP here in Florida in 92-96°F all summer long and have not noticed any out of the ordinary battery temps, also fly back to back batteries with maybe 10 minutes between packs with no adverse effect so far. Have an average of 20 charges p/battery (3 batteries). Have never actually checked the temp as I don't have a reader to do so.
Your not flying with the bubble on right?

QuadKid Posted at 2018-6-24 13:14
I agree 56C is warmer than it should be even running in sport mode, how many charges have you run through them? Are all you batteries doing the same thing?

MY batteries touching on and going beyond 70C at times in sport mode.  Atleast that’s what they indicated in app which may or may not be accurate.

Here is the scale I use I came up with:

Ideally 30-60 C should be kinda range normal operation in moderate to hot environment should see.

60-70C isn’t dangerous but it isn’t ideal range either. Probably have aging cells with higher internal esistance.

70-80C is really cooking, probably not dangerous but on the edge of problems. Damage is probably beginning to occur really need to replace the pack.

  80-90C probably looking at complete cell failure and potential autoignition on upper side of that. Damage is defiantly occurring at the very least

90-100C probably on fire...not even sure how it’s even still working.    best to look for a landing spot  that won’t catch fire it the battery pops.

100-110C. ??????   The hell..?

Hi, thank you for your query, with regard to your concern, flying your aircraft with 50 or high degree Celsius would be dangerous to your battery that might lead to an explosion or overheat, we also stated that information on Mavic Pro Intelligent Flight Battery Safety manual. Please see the picture below.

DJI Tony Posted at 2018-6-25 12:30
Hi, thank you for your query, with regard to your concern, flying your aircraft with 50 or high degree Celsius would be dangerous to your battery that might lead to an explosion or overheat, we also stated that information on Mavic Pro Intelligent Flight Battery Safety manual. Please see the picture below.

[view_image]

Thanks tony, but the aircraft is a mavic air. That being said, i would agree with your statement about flyong above 50 c.

Hello all, I have finished some testing. So, flight conditions are 65 degrees f with 4mph winds and 7mph gusts. Battery 1 had a temp of 53 degrees flying around at about 14mph to battery level 20%. Battery 2, the original toasty boiler, was 57 degrees c after hovering 100 ft and take 5 second interval shots before landing with 12%. The heat dissipated after landing at a rate of .2 degrees every 5 to 10 seconds. Also battery 1 has 10 cycles while battery 2 has 14, I hope this is more helpful than my incorrect estimates of 30 or more cycles.

Alpha

DJI Tony Posted at 2018-6-25 12:30
Hi, thank you for your query, with regard to your concern, flying your aircraft with 50 or high degree Celsius would be dangerous to your battery that might lead to an explosion or overheat, we also stated that information on Mavic Pro Intelligent Flight Battery Safety manual. Please see the picture below.

[view_image]

DJI Tony,
Much of the conversation here seems to be surrounding the temperatures that the batteries attain.  Do you have any information to share that can give your customers the acceptable temperature ranges of the BATTERIES.  

I also run NiMH and LiPO batteries on RC cars.  The harder they are pushed, and the longer they are run, the temps can soar.  It becomes clear that it's not the ambient environmental temperatures, but the current draw that creates the high battery ( and ESC, and motor ) temps.  70-80C is the higher range in Cars and Trucks... is there a comparable range with DJI batteries before we should be concerned?

AlphaFlightNW Posted at 2018-6-25 18:43
Hello all, I have finished some testing. So, flight conditions are 65 degrees f with 4mph winds and 7mph gusts. Battery 1 had a temp of 53 degrees flying around at about 14mph to battery level 20%. Battery 2, the original toasty boiler, was 57 degrees c after hovering 100 ft and take 5 second interval shots before landing with 12%. The heat dissipated after landing at a rate of .2 degrees every 5 to 10 seconds. Also battery 1 has 10 cycles while battery 2 has 14, I hope this is more helpful than my incorrect estimates of 30 or more cycles.

Alpha

Hey Alpha...quick question... In your original post you said your were flying in 90 degree weather.  Was that C or F ?  Not critical to the conversation... I'm just curious.  Thx

WebParrot Posted at 2018-6-25 19:14
Hey Alpha...quick question... In your original post you said your were flying in 90 degree weather.  Was that C or F ?  Not critical to the conversation... I'm just curious.  Thx

Well, im pretty sure im not flying in hawaii so it was more than likely Fahrenheit. Dont think the drones like lava.

We want to know the upper limit temperature of battery before caused any damage to it. DJI should let us know the temperature limit of battery not just the environment. The longer fly time and faster speed will cause battery temperature much higher than the environment.

AlphaFlightNW Posted at 2018-6-25 18:36
Thanks tony, but the aircraft is a mavic air. That being said, i would agree with your statement about flyong above 50 c.

The same thing on the Mavic Air battery, you might want to check it on the Mavic Air Intelligent Flight Battery Safety Guidelines. Please see the manual image below.

DJI Tony Posted at 2018-6-26 08:51
The same thing on the Mavic Air battery, you might want to check it on the Mavic Air Intelligent Flight Battery Safety Guidelines. Please see the manual image below.

[view_image]

Alright, what can i do besides flying shorter flights to prevent the battery overheating? I have come to the conclusion that operating in 65 to 90 degree f weather does not significantly chanege the rate at which the battery heats up.

AlphaFlightNW Posted at 2018-6-26 09:00
Alright, what can i do besides flying shorter flights to prevent the battery overheating? I have come to the conclusion that operating in 65 to 90 degree f weather does not significantly chanege the rate at which the battery heats up.

The rule of thumb I use, is to keep my drones (SPARK / MAVIC AIR / ETC) indoors (usually in A/C) until I'm actually ready to fly.  This goes for both in the winter time and in the summer.  Never leave anything in your car.  I know sometimes easier said than done at times but it's the best advice I can offer.

AlphaFlightNW Posted at 2018-6-26 09:00
Alright, what can i do besides flying shorter flights to prevent the battery overheating? I have come to the conclusion that operating in 65 to 90 degree f weather does not significantly chanege the rate at which the battery heats up.

almost true yes.  its like anything that heats up and is cooled by ambient air temp.   higher ambient temps doesnt change the rate at which it heats up but it does impact the initial and final points on the temperature curve..  by how much depends on usage (power you demand from it) and age/health of the pack.  

with batteries age/health is as big factor as how hard you push them.    older li-po have higher internal resistance which increases the rate that heat up at and discharge at.. same thing with a battery of poor health, it usually suffering high internal resistance causing some voltage droop and leakage of current (phantom battery draw).

RGMGFitness Posted at 2018-6-26 09:46
The rule of thumb I use, is to keep my drones (SPARK / MAVIC AIR / ETC) indoors (usually in A/C) until I'm actually ready to fly.  This goes for both in the winter time and in the summer.  Never leave anything in your car.  I know sometimes easier said than done at times but it's the best advice I can offer.

Interesting, I'll keep that in mind. Most of the time my drones come from a ac area before flight though sometimes my car does get a bit warm in the summer so I'll watch out for that as well. Does aclimating in the shade help as well?

I checked my battery temperatures yesterday after flight and I had 53°C. That temperature is fine isn't it? Obviously that feels relatively warm when touching with the palm of your hand.

The battery safety guide only mentioned not store the battery in place over 45 degrees C. It didn’t mention the temperature after usage which is much higher than that.

GDL Posted at 2018-6-26 21:53
The battery safety guide only mentioned not store the battery in place over 45 degrees C. It didn’t mention the temperature after usage which is much higher than that.

Exactly. Normally my MA is left one for a few minutes after landing to left the fan cool off things, though by the time im done flying, the battery is safely stowed in a cool location, such in the shade or a cooler location. That being said, i dont thermal shock the battery by walkung into an area with drastic temperature changes.