Mavic mini fly more kit batteries damaged in charger - is it possible?

[paulatkin73]

hi, i do suspect all 3 of my batteries went dead. quite frustrating and unclear what it is.
i left them sitting in the charger - the fly more, on 3 batteries. it was in there for a while, always kept them there, since new. charged them. uncharged them - so, they sat there may be for a month with 2 lights of of 4 charge left - seemingly all ok.
i just tried to charge them - all exhibit same pattern - in the charger they go into rapid cycle, then i hear some hissing noise coming - no smoke yet - no heat, no expansion, but rapid charge cycle then alters into an extremely slow one with a very slow changing of leds.

if battery is in the bird - same thing happens but with no hissing sound. so, i get batteries are not charging anymore.

can it be one of issues with last firmware? not sure. very sad, to lose all 3 lipos like that.

 

[Deleted member 103366]

A thread to watch I think, I too store my batteries in the flymore charger

 

[paulatkin73]

does anybody know the pinout of those **** batteries? i stored them in that charger forever. i definitely blame .500 firmware - it was the only factor that changed. i keep them now for an hour - see very slow blinking like a delayed charge cycle blink - nothing chnages, i do not think they are charging. will see.

so, does anybody know if it is possible to see per cell charge level?

 

[Deleted member 103366]

Might these be of use Mavic Mini battery info

DJI Mavic Mini Teardown : What's inside?

Buy your Mavic Mini today! It has become tradition here at RC Geeks to tear apart any new tech we get in. We love to see how the manufacturer has put it together and our engineers get first hand experience on how future repairs might be carried out. We also know it can be a useful resource for...

www.rcgeeks.co.uk

You can also get inline USB ammeter/voltmeter/amp-hour-meters

 

[old man mavic]

i have stored my batteries in the charging hub ,the three that came with the combo and the 4th one in the drone,without any issues up to now
the hub itself is not actually a charger it just distributes the power from the mains to the batteries in the order of the one with the most charge left first and so on it also acts as an indicator of amount of charge remaining as unlike the batteries of other mavics the MM batteries do not have any charge level lights built in
also the MM batteries do not self discharge after a set no of days like the other batteries do,thats why it has an outlet so you can discharge any fully charged ones using the USB port to your phone or some other device this needs to be done one at a time so the remaining charge does not get to low

 

[paulatkin73]

Paul Atkin Posted at 6-18 08:03
they were stored like that for a year with previous firmware. it is not an issue how they were stored.
update - after an hour in this extra slow cycle it went from 2 leds to 3 leds cycle - so it is charging. i guess after it gets above 50% i will downgrade to .400 to see if it fixes this cr@p. very frustrating stuff.

jesus f christ. i found what that is. and it is definitely a firmware induced thing.
so, i was using all this time, since the beginning - a power adapter from samsung phone. it had 5v and 9v levels and was ALWAYS doing fast charge cycle fine.

i found now an another power brick - from DJI smart controller. it started fast charge cycle and maintains that cycle. so it appears 5v or 9v is not enough now to do ANY charging - or they had added something to understand i am not using a DJI branded charger - as i tried 3 other USB chargers on my desk - 2 were fast chargers, one was not - they all would produce an extra slow charging cycle.

it is seriously odd.

PS. downgraded bird to .400, with battery in it - i think it did not alter battery code as behavior did not change. as this point i give up - will use DJI smart controller charger from now on.

 

[lowellton]

hi, i do suspect all 3 of my batteries went dead. quite frustrating and unclear what it is.
i left them sitting in the charger - the fly more, on 3 batteries. it was in there for a while, always kept them there, since new. charged them. uncharged them - so, they sat there may be for a month with 2 lights of of 4 charge left - seemingly all ok.
i just tried to charge them - all exhibit same pattern - in the charger they go into rapid cycle, then i hear some hissing noise coming - no smoke yet - no heat, no expansion, but rapid charge cycle then alters into an extremely slow one with a very slow changing of leds.

if battery is in the bird - same thing happens but with no hissing sound. so, i get batteries are not charging anymore.

can it be one of issues with last firmware? not sure. very sad, to lose all 3 lipos like that.

mine cant charge to 100% ever since. After full charge it only shows 93%

 

[Deleted member 103366]

If of use,
from the DJI charger I see 11.4V and 1.52A when charging a battery in the hub.
From an Apple 5V 1A iphone charger I see 4.87V and 0.46V " " " "
From a Hudl (Tesco tablet) 5V 2A charger I see 5.29V and 0.61A " " " "
from a Samsung 5V/9V 2A/1.67A charger I see 8.69V and 0.84A " " " ",
the speed with which the LEDs cycle seem 'proportional' to either the voltage or current, I don't know which

 

[paulatkin73]

the point is - it refuses to charge now from ANY other charger at all without switching into that extra slow charging cycle. i think they must have added something to sense if DJI charger is connected. i forgot when the previous battery code was updated - it probably was not in the .400 code - it may have been in .300 or even in .200, but it refuses to downgrade lower than .400, so, no way for me to do anything else now.

 

[Woodsman]

The Mini uses Li-ion batteries, not LiPO. Their characteristics are very different. A Lithium-Ion battery should be charged when returning home and will keep its charge for a good while. The Lipo will self-discharge after 2 days to a midpoint and hold.
This may have nothing to do with your problem, but battery care for the Mini vs Air, etc. is critical. The "Smart" controller in the battery reads the two cell balance and if one is overcharging you should hear about it when in the aircraft.
I had the jumper between the cells break inflight and we had a fast safe landing, with battery failure screaming on the display.

 

[Capt KO]

Cables make all the difference in charging rate. A 2amp charger will only output at the cable rate,thus slow blinking. Using a USB volt/amp meter will show the dramatic difference. Just tried out 3 dif brand cables to charge my Mini. 5v / 2a output rated charger. Both wall and power pack results.
#1 = 1.98a,
#2 = 1.50a,
#3 = 0.70a.
Same charger, different cables. If slow charging is your problem most likely it is your cables.
Anything below 1amp will show sloow blinking leds. The supplied white cable is 2amp rated.

 

[Capt KO]

My Yx multi charger will charge all 3 batteries from 30% to full in about 25 min. (They claim 50 min) Try that with the Mini battery pack by USB and it can take over 2.5 hrs! I even carry it on the road to use with my ac/dc inverter. The original charging system is stupid slow. The Yx charger, for mini, is well built and inexpensive too. Paid $30 AliEx but $40 - 50 in US. Worth it to stop the aggravation. ?
Good luck

 

[DiyTechno]

jesus f christ. i found what that is. and it is definitely a firmware induced thing.
so, i was using all this time, since the beginning - a power adapter from samsung phone. it had 5v and 9v levels and was ALWAYS doing fast charge cycle fine.

i found now an another power brick - from DJI smart controller. it started fast charge cycle and maintains that cycle. so it appears 5v or 9v is not enough now to do ANY charging - or they had added something to understand i am not using a DJI branded charger - as i tried 3 other USB chargers on my desk - 2 were fast chargers, one was not - they all would produce an extra slow charging cycle.

it is seriously odd.

PS. downgraded bird to .400, with battery in it - i think it did not alter battery code as behavior did not change. as this point i give up - will use DJI smart controller charger from now on.

You can try use certified Quallcomm quick charge 3.0 18W. This charger will communicate with dji charging hub, if the charger is compatible with QC 3.0 then it will increase charging voltage to 12V.

 

[kidroc]

Hard lesson my friend.. never ever leave batts on a charger especially if you have it unplugged it drains the down to nothing and kills them..

 

[Ramjam61]

I agree with Woodsman here. Lithium ion batteries should be fully charged after each flight and if not used within one month, charged up again. I use Lithium ion in some of my RC gliders and also have an electric cycle which get the same treatment. That hissing sounds like the batteries venting gas, once they do that they never recover to their original state. Your issue may be different but I thought I would add my experience with Lion batteries.

 

[BokiFly]

I agree with Woodsman here. Lithium ion batteries should be fully charged after each flight and if not used within one month, charged up again.

That is quite different to what some others here recommend, and to what is stated in Mini's Manual: "If the battery will not be used for more than 10 days, it is recommended to discharge the battery manually until the battery level is between 39% and 75%."

My Yx multi charger will charge all 3 batteries from 30% to full in about 25 min

Will that rapid charge hurt the batteries in any way?
I agree that Mini battery pack is very slow so I an interested in faster charging, but I am concerned will that harm batteries.

 

[Ramjam61]

That is quite different to what some others here recommend, and to what is stated in Mini's Manual: "If the battery will not be used for more than 10 days, it is recommended to discharge the battery manually until the battery level is between 39% and 75%."


Will that rapid charge hurt the batteries in any way?
I agree that Mini battery pack is very slow so I an interested in faster charging, but I am concerned will that harm batteries.

That's what I read too. However that is conflicting advice on all other manufacturers advice for the devices I own that are fitted with Lion batteries.

 

[TDZHDTV]

the point is - it refuses to charge now from ANY other charger at all without switching into that extra slow charging cycle. i think they must have added something to sense if DJI charger is connected. i forgot when the previous battery code was updated - it probably was not in the .400 code - it may have been in .300 or even in .200, but it refuses to downgrade lower than .400, so, no way for me to do anything else now.

I use DJI combo charger and Ravpower QC3 charger, both charger fast charge without issue, DJI are not penalising you for using non DJI charger.

 

[Ramjam61]

A bit more research (I find stuff like this intriguing). Allowing a Lion battery to discharge below 75% can reduce it's cycles to between 300 to 500 before it's demise. Keeping it above this can increase it's cycles to 2000 to 2500. In the case of phones/Laptops etc, keeping them on trickle charge overnight is far less detrimental than a longer charge next day. This all comes from the popular mechanics website.
The above advice has been the same as my observations. I always fit large capacity batteries in my RC gliders so even after all day flying they are still above 80% capacity. Two gliders have batteries that are 8 years old. I would love to know what dji's thinking is behind their advice. Maybe their battery tech' requires a different approach to everyone else's?

 

[BokiFly]

Allowing a Lion battery to discharge below 75% can reduce it's cycles to between 300 to 500 before it's demise.

Very interesting.
But I don't like this confronting information
It would definitely be more convenient if it's true that we can charge batteries to full after flight. Charge and forget. I would like that. On the other hand this charging and discharging at around 50% is more demanding. Not to mention that if you have batteries at 50% and suddenly you have great opportunity to go out and fly then you can't do that, and that can be very sad.

But we need to be careful about this because there must be some reason why DJI stated "If the battery will not be used for more than 10 days, it is recommended to discharge the battery manually until the battery level is between 39% and 75%."