What DJI drones have the best batteries?

[iAMiRONMAN]

What I mean by best battery is that it does a good job keeping its capacity over the years and doesn’t melt or fail?

 

[old man mavic]

@iAMiRONMAN i can only speak from my experience with my MPP but i have had no issues with the batteries so far or indeed with the MM ones yet ,i dont think that it possible to say that a particular cell count makes a great deal of difference ,although i feel that the 4 cell ones in the second gen mavics ,do seem to suffer more from swelling than the three cell ones,but that could be because more people are reporting issues with them ,its really down to how you charge them ,store them, and use them ,that affects their lifespan more than anything else,although the common thread running through battery life,issues reported on the forum, seems to be letting them get too hot when using them and charging them

 

[iAMiRONMAN]

I wonder if the bump in performance and flight time with the 4-cells has come at reducing reliability. Things can and do happen like this. It’s never planned but sometimes real world use puts more of a strain on particular components than in-house pre-production testing revealed.

Could the heavy use of sport-mode be the source of most swelling because of the rapid energy dump needed for the power boost.

 

[old man mavic]

I wonder if the bump in performance and flight time with the 4-cells has come at reducing reliability. Things can and do happen like this. It’s never planned but sometimes real world use puts more of a strain on particular components than in-house pre-production testing revealed.

i have mentioned and come to the same conclusion myself, in other threads on battery issues with the M2Ps that although the second gen mavics are a step up in performance in all areas sensors, camera, occusync, etc, that to get the extra flight time, because it was heavier and used more battery power to run all the features, that a 4 cell battery was needed

 

[iAMiRONMAN]

i have mentioned and come to the same conclusion myself, in other threads on battery issues with the M2Ps that although the second gen mavics are a step up in performance in all areas sensors, camera, occusync, etc, that to get the extra flight time, because it was heavier and used more battery power to run all the features, that a 4 cell battery was needed

Unless improved battery tech becomes available to DJI during their design and engineering phase of a new model production, it would seem any new and differentiating features (other than minor camera/sensor improvements) would require a 5th or 6th cell going forward. This would come at increasing weight and price and more of a move into the more profitable enterprise sector.

 

[old man mavic]

thats the problem with upgrading any system family ,once you reach a certain point you loose the advantages and reasons for a particular model, and it reaches a point that cant be gone beyond without compromising the original concept i personally think that that point has already been reached with the mavics in their present form,

 

[Deleted member 129058]

MP great flight times about 30 minutes!

 

[everBit]

it does a good job keeping its capacity over the years

A lot of DJI batteries have passed through our workshop, but the best samples were from DJI P3 which served around 300 cycles since 2015 and still keep 30% of their rated capacity.

The worst turned out to be from DJI Mavic Air and M2P, a lot of them dated by 2018 already swelled anough at only 60 cycles.

The reason could be that since Mavic Air DJI has started to pump-in more power in the cells to increase flight duration, so cells are now charged to 4.40V vs 4.35V in previous generation batteries.

In that respect the favorite of good batteries could be the Mini's ones where cylindric 4.2V 18650 Samsung Li Ion cells are used.

 

[bumper]

Considering only the battery, and assuming the same battery technology, flight time and performance is not just about the number of cells (which determines system voltage), but also about individual cell amp hour capacity or size (which determines system current). A common analogy is a water hose or pipe . . . voltage is analogous to pressure, while current is analogous to flow or pipe size.

There is an efficiency advantage going with higher voltage, as there is a corresponding decrease in wiring loss (the power lost to resistance in wiring, including the important motor wiring).

I suppose one might postulate that more cells translates to more battery problems, but I guess the same argument could be made that correspondingly larger cell size would have the same effect. I'd think battery manufacturing quality would be the main factor. That, and importantly how the consumer treats the battery.

 

[SkyeHigh]

I wonder if the bump in performance and flight time with the 4-cells has come at reducing reliability. Things can and do happen like this. It’s never planned but sometimes real world use puts more of a strain on particular components than in-house pre-production testing revealed.

Could the heavy use of sport-mode be the source of most swelling because of the rapid energy dump needed for the power boost.

The problem with the 4-cell LiPo’s in the Mavic 2’s is insufficient space was left in the plastic case to accommodate the slight swelling during charge and heavy discharge cycles.

 

[brett8883]

Considering only the battery, and assuming the same battery technology, flight time and performance is not just about the number of cells (which determines system voltage), but also about individual cell amp hour capacity or size (which determines system current). A common analogy is a water hose or pipe . . . voltage is analogous to pressure, while current is analogous to flow or pipe size.

There is an efficiency advantage going with higher voltage, as there is a corresponding decrease in wiring loss (the power lost to resistance in wiring, including the important motor wiring).

I suppose one might postulate that more cells translates to more battery problems, but I guess the same argument could be made that correspondingly larger cell size would have the same effect. I'd think battery manufacturing quality would be the main factor. That, and importantly how the consumer treats the battery.

Bigger cells aren’t necessary more problematic than smaller cells. Actually to the contrary they are usually better all else equal with a higher discharge rate that increases with the capacity of the cell. This is why it’s rare to see battery packs with cells in parallel except at the highest range of the spectrum. Less cells is almost always better.

A battery pack will fail if even one of the cells fail so the more cells you have the more opportunity you have for failure.

 

[bumper]

Bigger cells aren’t necessary more problematic than smaller cells. Actually to the contrary they are usually better all else equal with a higher discharge rate that increases with the capacity of the cell. This is why it’s rare to see battery packs with cells in parallel except at the highest range of the spectrum. Less cells is almost always better.

A battery pack will fail if even one of the cells fail so the more cells you have the more opportunity you have for failure.

True, however, to get more performance (motor power), while still conserving weight (battery packs with more voltage allow use of smaller wiring size for a given power output), a system with more voltage offers advantages when weight vs performance are the major concerns. It's a win-win, even when you consider the increase in chance for failure. If that chance for failure is very small to begin with, increasing it by 25% (4 cells vs 3), the chances are still small.

There was a bad batch of M2 batteries before I purchased mine. They were swelling according to reports here. I purchased 2 M2's last Nov & Dec. I have 5 batteries, no problems so far.

 

[brett8883]

True, however, to get more performance (motor power), while still conserving weight (battery packs with more voltage allow use of smaller wiring size for a given power output), a system with more voltage offers advantages when weight vs performance are the major concerns. It's a win-win

I agree but that wasn’t the question. It’s which battery is the most reliable and least likely to fail. If we both agree that a 4s battery is 25% more likely to fail than a 3s battery at the same cell size then we both agree that the M2 cannot be the most reliable given that the MP has a 3s battery and almost exactly the same size cells.

The P3 battery is interesting as a candidate because it does have significantly larger cells than the MP while maintaining only 4s.

 

[brett8883]

Oh I forgot we have the Mavic Mini 2s lithium-ion 18650 pack which in theory should be by far the most reliable and long lasting battery. It’s too new to prove that but that’s what I would put my money on

 

[Mrmund]

DJI Spark batteries. Old, tons of flights, all 4 batteries still good

 

[Made2Phly]

...The reason could be that since Mavic Air DJI has started to pump-in more power in the cells to increase flight duration, so cells are now charged to 4.40V vs 4.35V in previous generation batteries.
[QOUTE]

Do 4.40V and 4.35 V equate to percentage of charge at all, and if so, I guess 4.40 would be 100 %?
I ask because if charging my batteries to less than 100% each time would prolong their life, or reduce the risk of swelling, I would consider it.
I

 

[everBit]

Yes, those voltage thresholds are referred to 100% of charge accordingly.

Me totally agree with you in the respect that reducing full charge voltage limit would prolong battery service and reduce swelling probability.

But equally it will reduce flight time.
Just some figures based on experiment with DJI Mavic Air battery 2375mAh 11.55V (3S) 27.43Wh.
Charged by SkyRC B6 mini using LiHV 4.35V 3S profile first, then changed to LiHV 4.40V 3S profile (same as DJI standard charger is set). After programm finished Amper-hour meter shows 200mAh more charge pumped in.
It's 8.4% in the measure of designed capacity and 9.5% of designed energy.
Having in view that drone is consuming energy rather then capacity one should expect 9.5% reducing in flight duration with that approach.