Mavic Air battery questions


#1

I’ve used the drone maybe 20 times since buying it in March '17. The point being that the batteries have been charged about that many times and maybe less. I was told on this forum that if you charge the battery and say a day or two later, press the status button, it will reset the auto discharge clock to keep the battery fully charged. That sounded good but left me the other day with a problem…

I charged both batteries and a few days later went to fly my drone. One batter was showing only 2 or 3 LEDS, while the other showed all 4. This happened again. Thats when I learned of the auto discharge feature. I was then baffled by the difference between two I think identical batteries, treated the same careful and proper way.

I charged them both. One day later pressed the button. Checked. One day later and pressed the botton. On day 3, one of the batteries had lost a chunk of charge and the other was fine. I repeated this with both batteries disconnected from the drone in case one was getting charge leaked away that way. Nope. So, my question is this. Is one of them duff? It fells likely to me. I’ve applied any firmware updates that came my way. Should this be covered by the shops guarantee or do I need to battle with the DJI staff too?

Thanks.


#2

Hi @tommyQ

Possibly…

And possibly not…

The auto-discharge setting needs to be applied per battery. This is something I only found out a couple of weeks ago :scream:

I’d also take a deeper look inside the GO4 app (and/or the premium version of AirData) as it will give you the voltages for each cell in the battery pack and may well provide insight to a potentially duff cell.

First things first though, check the auto-discharge setting on each battery :+1:t2:

Depends where you bought it… The likes of Argos and Amazon are pretty good these days and will usually just replace without argument. Other retails may well refer you straight to DJI.


#3

Thanks for your speedy reply. I bought this from Hobby Mounts UK. I’ve no reason to suspect them as a company - certainly at this stage. I’ll peek at this, but I thought from a previous thread it was said that option had gone . To adjust the discharge delay?? I couldn’t see it but I’ll look again. They also suggested to flatten both to about 10% and re-charge. Any thoughts on this too would be great.

I have a feeling early on when I got the drone, it wanted to do a firmware update on the drone, RC and battery. I dont recall looking back if it prompted ever about the 2nd battery, so they could be running different firmware. Does this sound possible AND if so, can it be forced to do the update if so?


#4

They are brilliant! :+1:

Yes - for the M2P and M2Z … not from previous DJI drones.


#5

I have said this before…

There is NO discharge delay option for the Mavic Air

Try the update process using the DJI Assistant 2 as this is how I updated my batteries, see what happens. I would have thought if one of them has not been updated it would be picked up


#6

I’ve also just read that pressing the power button on Air and possibly M2P does not reset the discharge counter. Only a power cycle will.

Can you confirm that Paul?


#7

I cannot confirm nor deny :smiley:

It is not something I do to be honest. If I plan on flying I charge the batteries the night before and if I don’t manage to get out for whatever reason I will leave the batteries to discharge on their own. I have never used the practise of pressing the button to reset the discharge but merely to see how much charge is left. If I plan on flying the following weekend then I will put them on charge again.

There is no mention in the MA battery manual about resetting the discharge process, maybe it’s a MP thing.


#8

I think DJI may have removed it to stop people leaving at high charge for extended periods.

I did it ocassionaly if I was nearing the 10 days and knew I’d be going out in next couple of days but I’m sure some people probably kept it going for many weeks.


#9

In the last 4 months I’ve only flown once with one battery and I have three batteries. I have the MP1 so I’ve been resetting the discharge clock every once in a while. Charged them fully once or twice within that time.


#10

Sorry for the delay in replying to all your answers. So far, I’ve ascertained that in each battery, the 3 cells all show a very close voltage as they discharge. For example, right now while I’m discarching the 2nd battery, I get: 3.74, 3.71 and 3.71 giving 11.17v (not 11.16v) overall and showing 30%.

The charge cycle counters show 5 for one and 6 for the other. On start up of the DJI GO4 app I do get the version checking’ prompt and it doesn’t seem to require any updates with either battery in the drone.

In the ‘About’ options, I see aircraft and RC versions but not battery. Is there any way to find out what this is? I get serial number info and production date. These are one month apart. The earlier suggestion about taking the batterys down to 10% and then recharging them both was in part in case I’d used one battery more than the other but with recharge counts of 5 and 6, I suspect that isn’t quite the answer? I may have flattened one more each time it was used so I’ll continue and get back.

I’ll look into the go 2 assist thing, though I dont know what that is just now. I’ve read/heard about it. I’m assuming its different to the phone app ‘GO 4’ ?


#11

I’ve found it… Just got to find my cable and see what happens…


#12

A very late update to my question. The shop had said discharge the batteries to about 10% and see what happens. I have to report (to my suprise) that they are both performing much better for reasons I dont understand. I thought these batteries behaved very differently to Nickle Cadmium cells. However, I think I’m happy now. As I’d never fully discharged these, maybe they adjusted their idea of the low point calculating the percentace drop accordingly.


#13

I may have a need for absolute max air time for something I’m planning, and should actually do a max flight (even if just a hover) to check what I’m really able to get from my 3 batteries (to make sure it will get home and not try swimming).
And, whilst there are no known/obvious reasons to do really low discharge cycles on them - as you’ve suggested, it’s more likely to give me (a) longer flight time, (b) more accurate estimate of time remaining than do any terminal damage … so probably something I will do at that time.


#14

I agree that you shouldn’t need to do this but it did somehow make a difference for me. My thinking is that if the firmware in the battery controller is in error in some odd way. Flexing the battery by taking it actually low did help.

I’ll keep an eye on it and report back if I see anything useful. I like the rather sensible idea you make of making a flight time test. I recall somewhere from a flight log video that you need to be mindful about flying back when you are also going against the wind. Apologies if this is something you know.


#15

Having read from the top I have a couple more newbie questions.

Is there a specific procedure used to fully discharging air batteries?

Should air batteries be stored in any particular state? Ie should I recharge after a day out flying or should I recharge before going out? Perhaps it is both?

TIA


#16

I don’t think the Spark, Air and MP have to be deep cycled, I can’t see anything in the manual for the Spark or MP anyway.
As for charging it’s best to do this the day of or the previous day that you intend to fly.
You shouldn’t store fully charged batteries, although I’m guilty of this as I normally charge to go out and then life or weather changes my plans.


#17

Agreed!


#18

I just put mine in the drone and left it there but using a methog I’d been given on this forum, kept an eye on battery temperature. I waited until they were down to about 10% . From the problems I was having, the batteries seemed to behave in the same fashion, but one still discharges earlier than the other. I think they have the same capacity, but one just decides to do the auto discharge earlier?

The batteries also keep a count of the charge cycles so I’d agee it’s probably better to charge when you think you will use the drone and for safety and battery health, store with less in.

I