Post Flight Battery Cooldown

[3rdof5]

Greetings Pilots,
I'm wondering if anyone has a specific procedure for aircraft/battery cool down after landing.
I always monitor my battery temperature and cell voltages while flying.
Often, I will land and restart the props and let it idle on the pad to cool and let cell voltages stablize abit under light load.
I've done this with all my aircraft, particularly on hot days where my battery temps are above 50C and I've never had battery issues.
Anyone else do anything post flight?

 

[MS Coast]

Greetings Pilots,
I'm wondering if anyone has a specific procedure for aircraft/battery cool down after landing.
I always monitor my battery temperature and cell voltages while flying.
Often, I will land and restart the props and let it idle on the pad to cool and let cell voltages stablize abit under light load.
I've done this with all my aircraft, particularly on hot days where my battery temps are above 50C and I've never had battery issues.
Anyone else do anything post flight?

Is cooling the battery or stabilizing the cell voltages the concern?

If it's cooling, I'd think the battery cools more rapidly outside the drone without a load. I've not looked at post-flight cell voltage readings. Do you typically see a significant imbalance?

 

[3rdof5]

Is cooling the battery or stabilizing the cell voltages the concern?

If it's cooling, I'd think the battery cools more rapidly outside the drone without a load. I've not looked at post-flight cell voltage readings. Do you typically see a significant imbalance?

No I do not see alot of cell imbalances over 0.01 volts. But I did have one P3 battery (DJI) that I acquired with only 5 charges in 4 years and while it (and it's twin I also aquired) charged and flew fine, cells 1 and 4 showed up to 0.1 volt differences. I would monitor temp and cells post flight to see how they were balancing out. After a few cycles that battery is fine now.
I guess I'm just old school and don't believe in shutting down a hot engine without letting it idle and cool itself abit.

 

[MS Coast]

No I do not see alot of cell imbalances over 0.01 volts. But I did have one P3 battery (DJI) that I acquired with only 5 charges in 4 years and while it (and it's twin I also aquired) charged and flew fine, cells 1 and 4 showed up to 0.1 volt differences. I would monitor temp and cells post flight to see how they were balancing out. After a few cycles that battery is fine now.
I guess I'm just old school and don't believe in shutting down a hot engine without letting it idle and cool itself abit.

I know what you mean. I still do that with outboard motors and cars. And I switch off the car's air conditioner compressor a few minutes before arriving to reduce engine load and dry the evaporator so it doesn't stay moist and get funky.

But I'm thinking that with drones, the best option is to pull the battery and expose it to the ambient air and let the interior of the drone ventilate.

 

[3rdof5]

I know what you mean. I still do that with outboard motors and cars. And I switch off the car's air conditioner compressor a few minutes before arriving to reduce engine load and dry the evaporator so it doesn't stay moist and get funky.

But I'm thinking that with drones, the best option is to pull the battery and expose it to the ambient air and let the interior of the drone ventilate.

I guess that depends on the design of the drone, and in particular, their venting design.
I find my Mini 3 battery temp cools much faster idling with the props running.
The Mavic 3, with it's own internal cooling fan, takes care of itself nicely if you just land and leave it powered on.
With my Phantom, I always idle after a flight in hot weather until I notice the battery temp is starting to fall.

 

[StantonZ]

As was mentioned, the best way to "cool" the battery is to get it out of the drone.
However--just as important--is to not charge while hot...and balance that with not letting an almost empty battery (<20%) sit around like that for an extended period (like more than a day). If you have to fly a battery down to empty, bring it back up to 50% or so once it cools down...and then finish the full charge before you need to fly again (like the day of).

 

[Droning on and on...]

Often, I will land and restart the props and let it idle on the pad to cool and let cell voltages stablize abit under light load.
I've done this with all my aircraft, particularly on hot days where my battery temps are above 50C and I've never had battery issues.
Anyone else do anything post flight?

This is not the "old school" you speak of in a subsequent post. That was for mechanical engines using exothermic combustion.

What you are doing is 100% counter-productive for an all-electric, battery-based system. In fact, you are putting additional stress on the batteries taking closer to depletion.

Finally, sitting there running the electronics and idling the props is simply generating heat, delaying cooling.

The fastest way to cool things down is to turn it off immediately, then remove the battery to maximize the ambient air exposure to the battery casing, and the interior surfaces of the battery compartment.

 

[shawgod]

I always remove the battery immediately and lay it out. I never put it in a case. I let it cool down for at least an hour. I know that seems like a lot of time, but without putting the battery back into the drone, it is hard to know the internal temperature of the drone, so this way the guess work is taken out. Once I get home I will charge the batteries to 50% for storage or 100% if I am going to fly the next day, which is usually the case. After charging I will let them stay out of the case to cool down for about an hour then place them in the case.

 

[hiflyer201]

Often, I will land and restart the props and let it idle on the pad to cool

I see your point, but I think it's like an air-cooled engine. It's not cooling all that much when it's idling. You can't sit in the runup area all day with an aircraft on a hot day and the same with an air-cooled motorcycle in a traffic Jam. You've had great luck doing what you're doing so who am I to judge. I take the battery out as soon as possible and put it on a cool surface if I can.
On the same subject..I would never download from the drone unless it was absolutely necessary.