You CAN store your Mavic batteries on the charger without damaging them

[brett8883]

The information on this forum would tell you that if you plan on not flying for an extended period of time you should NOT store your batteries on the charger. You should discharge them to 50% and recharge them back to % when they go below 40%. There are numerous threads asking for storage mode chargers that would do this automatically. Yet, the stock charger already does this!

I usually fly my Mavic before the 5 days auto discharge starts so I never had a chance to test this. However, it’s been a while since I flew using all my batteries. and some of them have been sitting on the charger for a couple weeks.

I went to pack them up expecting them to be fully charged but no they were at 50% battery level! Meaning the auto discharge happened even though it was on the charger and the charger kept it at 50%.

I only have a Mavic Pro so I can’t speak for the other drones but I suspect this is the case for all of the Mavics (except maybe the mini since it doesn’t auto-discharge?)

I should also note that I use the charging hub so it’s possible this is due to the charging hub and not the battery but I doubt it. It all other cases the battery is the authority that governs it’s own charging and discharging.

Cool feature that isn’t documented by DJI as far as I can find.

 

[MAvic_South_Oz]

Ah, good find.
Then all you need to do is turn the power off at the wall, and flick it back on, batteries will charge up as normal without removing them.

So many things are not in the manual, you just explore, test, or find them out by accident.

 

[Meta4]

Cool feature that isn’t documented by DJI as far as I can find.

It's not a "feature".
The charger isn't doing anything, once the battery is charged, the charger shuts off.
It doesn't continue to trickle charge into the battery.

The thread title is misleading since leaving the batteries on or off the charger is exactly the same.

 

[brett8883]

It's not a "feature".
The charger isn't doing anything, once the battery is charged, the charger shuts off.
It doesn't continue to trickle charge into the battery.

The thread title is misleading since leaving the batteries on or off the charger is exactly the same.

No because leaving it off the charger will cause the battery to drain below 50%. Leaving it on the charger causes it to maintain 50% charge.

 

[Order66]

No because leaving it off the charger will cause the battery to drain below 50%. Leaving it on the charger causes it to maintain 50% charge.

Watching this one.

 

[Meta4]

No because leaving it off the charger will cause the battery to drain below 50%. Leaving it on the charger causes it to maintain 50% charge.

Are you sure?
How long were the batteries left on the charger?

 

[Simmo]

I've done that just recently. Left the Mavic Pro batteries on the hub, and left it all turned on.
I forgot about it for weeks and when I checked the batteries off the charger, both had two solid lights, flashing the third.
I've just put them back in the hub and they are being charged.

 

[brett8883]

Are you sure?
How long were the batteries left on the charger?

It was at least a 2-3 weeks.

 

[sar104]

No because leaving it off the charger will cause the battery to drain below 50%. Leaving it on the charger causes it to maintain 50% charge.

That's not correct as far as I can tell. I have a couple of MP batteries that I didn't use for 6 months - they auto-discharged to around 55% and stayed there.

 

[brett8883]

That's not correct as far as I can tell. I have a couple of MP batteries that I didn't use for 6 months - they auto-discharged to around 55% and stayed there.

Well wouldn’t you expect for a lipo to lose charge? I suppose it’s possible they just discharged down to 50% and stayed there as you say but at least I have debunked that keeping them on the charger is a bad thing

 

[MAvic_South_Oz]

Feature or find, it's good to know.

I'm not sure if the charger would just shut off after a full charge, then either :
The batteries just discharge down to the usual~ 50%, and the charger remains off while the battery/ies continue to gradually lose a very small fraction of % over a long time.
Or, continue to maintain the battery in the discharged state of ~ 50%.

I think it would be the former, as it takes literally months for the slow loss to occur after discharge.

One way to check is does the charger continue to cycle on after the auto discharge has done its job ?
You might be lucky to catch this, as maintaining could be a short burst every day or two ?

Another way might be to take one battery off the charger, and leave other one or more on the charger . . . monitor level status after a few more weeks, either by light status, or better volt meter or put the 2 test batteries in aircraft to compare levels of charge.

 

[sar104]

Well wouldn’t you expect for a lipo to lose charge? I suppose it’s possible they just discharged down to 50% and stayed there as you say but at least I have debunked that keeping them on the charger is a bad thing

I don't have any particular expectation on loss of charge - all I can say is that I have observed that they don't, or at least not at any detectable rate. I think the chargers turn off once the batteries are charged, and so I would expect that leaving them on the charger is no different to leaving them off the charger.

 

[brett8883]

I don't have any particular expectation on loss of charge - all I can say is that I have observed that they don't, or at least not at any detectable rate. I think the chargers turn off once the batteries are charged, and so I would expect that leaving them on the charger is no different to leaving them off the charger.

And maybe that is the case but still good to know right?

People can breath easy that they can leave their Mavic batteries on the charger as long as they like without fear of damaging it. As you said it’s “no different than leaving them off the charger.” That is worth pointing out I think and different than what has been the typical advice being given on the forum.

 

[brett8883]

Here I’ve updated the name of the thread to “You CAN store your Mavic batteries on the charger without damaging them”

This has been a good talk and I hope it has been helpful.

 

[RayOZ]

I doubt DJI charger would continue to trickle charge the batteries. I expected it to switch off altogether after it fully charge the battery and it doesn't monitor the battery after that. It would be a fire hazard if someone leave it on the charger with the charger on and forgot about it for a few months for the winter.

 

[jzilla80]

This would indeed be a nice hidden feature. Possibly a great find! That our stock chargers keep our Mavic packs at optimal storage voltage! I say possibly because I find it hard to believe.

Its good to know that the battery packs internal circuitry does initiate its own discharge to storage level, while still on the charger, although I dont believe the charger monitors the pack after it reaches full charge. I think it just cuts power to that pack. (Although it would be a GREAT feature if it were so!)

I get why you came to these conclusions, because you expected to come back to your battery you left on your charger for 2 weeks and find it fully charged, as I did before reading your post, but what makes a quick and easy test impossible of how your battery was still at 50% after 2wks on your charger is the HV Lipo (any Lithium based battery cell) has a very slow naturally occurring self-discharge rate, so after the packs circuitry has ended its discharge load down to 50-60% storage level, your not going to see much natural self-discharge in the following 2 weeks, as it would take 6-8wks, or more, to see a 10% decrease, in most cases, and my guess is that rate of discharge would be the same whether or not you left your pack on the charger.

I want to believe that DJI wouldve thought of something like that, and simply added it for the sake of their customers without marketing the crap out of it, but its just not very plausible, imo. Then again, I was perplexed when I first learned about DJI packs having self-initiated drain to storage levels, as it collided with my viewpoint that manufacturers think that the worse their batteries are treated equates into more battery sales, so hey I could be all wrong?

If I am wrong and your 100% sure that your charger is what kept your pack at 50% then say so. Maybe I'll give it a try?

I appreciate your post!

 

[OurAngryBadger]

I'm skeptical.

I haven't flown my M2P for a month now (since covid ramped up here), I kept the batteries in the bag. Mine are all at 50% too (idk if it's exactly 50% but 2/4 lights are lit).

Maybe the battery just automatically discharges down to 50% and stays there no matter if it's on charger or not...

 

[old man mavic]

an interesting topic,can i just throw my two penneth into the debate
as we all know the hub allows 4 batteries to be charged in sequence, depending on how much remaining charge is left in the 4 batts in the hub
nothing happens till the charging brick is plugged into the mains, and after each battery has been fully charged and balanced ,it then moves on to the next one till they are all charged
so at this point whether the charge brick is removed from the mains or not,nothing will happen
and it seems that even if the batteries and the charger are left plugged in with the power on ,the batteries will start their self discharge but the charge hub does not react to this or the batteries would start to charge again and would be at 100% not 50% as in the OP
the only way to get the batteries to charge is to switch off the mains power and then the hub will reset and then allow the batteries to start charging again
the only thing i would say is it is maybe not best practice from a safety point of view to leave the charging brick connected to the mains and turned on when not in use

 

[Dave Maine]

Leaving them on the charger for long periods means that any time there is a power interruption to the charger, and the power returns, the battery, or batteries will be charged up to 100%, and allowed to start discharging again according to the settings saved in each battery.

Here in Maine, power interruptions are fairly frequent, and I certainly don’t want my batteries randomly charging and discharging.

 

[brett8883]

Leaving them on the charger for long periods means that any time there is a power interruption to the charger, and the power returns, the battery, or batteries will be charged up to 100%, and allowed to start discharging again according to the settings saved in each battery.

Here in Maine, power interruptions are fairly frequent, and I certainly don’t want my batteries randomly charging and discharging.

Well maybe this advice doesn’t work if you have unreliable power or live in a third world country or something. Just use common sense. Most people don’t have that issue.

Still the once in a blue moon cycle isn’t going to damage the batteries anyway.

Do we know that just power cycling the charger will take the batteries out of self-discharge mode? I feel like that sounds correct and I assume it to be the case but does anybody know for sure? I flew yesterday on a battery that was 50% auto-discharged and I had to turn the battery off remove it and turn it back on to get it to stop giving the battery status as “auto-discharge.” To be clear I’m not disputing it but do we know for sure?