How long do batteries last when shipped?

[Brian Fist]

Hey guys, I have an unopened Mavic 2 Zoom and a Mavic 2 Fly More Kit. Neither one has been opened and was purchased back in 2021/2022 timeframe.

I do a 13-16 month "charge cycle" on my drone batteries as preventative maintenance (Inspire 1, Phantom 4 Pro, Mavic Air, Mavic 2 Pro, Parrot Anafi, even my Osmo batteries). I have not done it on these since the packages have not been opened.

Question is, should I open them and charge them?

I know DJI does something special to batteries when they ship to withstand long "shelf life" before sale. I have opened Inspire 1 batteries that were 5 years old and they charged and had near full (like 98%) capacity and have performed just like a "new battery" with no ill-effects. Which is MUCH different than a battery you use a couple of times and then just charge once every 13-16 months to keep "fresh". If you don't charge a "used" battery like that you run the risk of it completely discharging and then it flat out won't ever charge with a power fail status internally in the BMS. Somehow DJI programs the BMS to not go into "monitor" mode until the battery is first charged, this allowing for much longer shelf life, but how much longer is the question?

 

[slup]

I know DJI does something special to batteries when they ship to withstand long "shelf life"

Well, it's not more special than that the BMS isn't active before you charge the batteries for the first time & by that the BMS doesn't add on any drain to the usual self discharge all LiPo's have.

...how much longer is the question?

Brand new DJI batteries, still in hibernation mode (deactivated BMS), are shipped on approx. 3,7-3,8V/cell (storage/resting/nominal voltage), the chemistry there are mainly inactive & can be kept perfectly fine there for a very long time without any alarming ill effects coming from self discharging... from my experience with generic FPV quad batteries (no BMS) they only lose like 0,05V at max over a winter season if the cells are healthy to begin with... so if the cells in the battery are well balanced, have equal behavior & performance they could be stored for years if placed on storage voltage (but be aware that the self discharge accelerates the further away they are from the nominal voltage).

One thing you can't prevent though, is capacity loss due to age... mainly that means that you should use the batteries you have while they still are new... not store them, if you want a good & performing battery.

I usually recommend others to start their spare batteries up just before the battery warranty expires to be able to claim the warranty if any of the spare batteries they bought was DOA... it's different in your case, the warranty have since long expired. My recommendation is to either sell them to somebody that will use them... or start to take them into your own battery rotation now while they still aren't ancient & should be reasonable OK after 3-4 years (they are probably starting to get out of that sweet spot 3,7-3,8V/cell & the self discharge may have started to accelerate).

 

[StantonZ]

Hey guys, I have an unopened Mavic 2 Zoom and a Mavic 2 Fly More Kit. Neither one has been opened and was purchased back in 2021/2022 timeframe.

I do a 13-16 month "charge cycle" on my drone batteries as preventative maintenance (Inspire 1, Phantom 4 Pro, Mavic Air, Mavic 2 Pro, Parrot Anafi, even my Osmo batteries). I have not done it on these since the packages have not been opened.

Question is, should I open them and charge them?

That's a really good question: have you asked DJI?
From experience with other Lithium battery types, I would question a "shelf life" of > 2 years. For example, I purchased a "new" Lithium battery module for an EV (high-dollar, high-capacity)...and it was "stone dead" (e.g. unusable) with a manufacture date ~ 2 years prior. The routine with your "in rotation" batteries is good, but we don't know what kind of test/prep DJI puts these batteries through before shipment.

 

[PHZ]

Or…. You could just try to charge them and see what happens. It is likely that unopened, untested batteries that are that old would have limited value to a buyer.

 

[slup]

...but we don't know what kind of test/prep DJI puts these batteries through before shipment.

I think we know a great deal... it's just that DJI have had a great success with their marketing of "Smart" batteries. If there exist any kind of DJI "magic" it will be in the chemistry if anywhere, but then doubt that it's optimized for shelf life over charge/discharge characteristics.

1. DJI have over the years used several sub-suppliers for their battery packs, Sanwoda, Donguang, Amperex, Huizhou Desay... just to mention some.

2. The exterior, assembly & capacity quality have according to users differed among different suppliers (have seen it myself also)... indicating that DJI isn't the one that manufactures the parts needed for a complete pack, including the LiPo cell pouches. DJI just outsource it to be manufactured according to a specification (which have tolerances).

3. All LiPo cell manufacturing follows a strict process in a controlled environment in order to achieve the desired performance... but deviations will occur even within the same production batch. This leads to at least 2 following sorting stages... one regarding characteristics, & one regarding performance.

4. Due to the production... or behaviour deviations that occur, the cells in a pack needs to be matched to get a good pack with a consistent behaviour out from all cells.

5. LiPo chemistry age... this occurs even if the chemistry isn't used. Well known signs of aging are less possibility to hold capacity & to some extent an increasing resistance.

6. A charged LiPo chemistry self discharge... non linear out from the nominal charge where it is relative inactive.

So with all above known facts, what can DJI do to extend the shelf life..?

Charge them to nominal voltage of course... and one other obvious thing is to prevent anything (the BMS) from discharging the battery pack on top of the usual self discharge. DJI batteries comes new with the BMS deactivated because of this reason... DJI call it "Hibernation mode" & it will also eventually revert into this mode even after the batteries have been used if the cell voltage goes very low (during storage for instance)... this as a last attempt to save the battery from falling down into damaging voltage levels.

 

[Brian Fist]

Thanks for the input guys.

I have enough drones that I kept the Mavic 2 Zoom as a "backup" more than anything. I have a Mavic 2 Pro that works just fine and I also have the Parrot Anafi that does zoom as well as a Z3 for my Inspire setups (I own a single V1 with upgraded pro gimble mount, two V2s, and a host of cameras including an X3 camera, Z3 camera, X5 camera and an X5R (Raw) setup) so the "zoom aspect" isn't a primary requirement, thus I kept it sealed and untouched as "one less thing to maintain".

I will probably open it up and the Fly More kit I have for it and make sure everything is proper. I even have a full hardcase I never used for it (I have the same for the Pro, holds the bird, two extra batteries, charger hub, cahrger, controller and a ton of extras).

Honestly, I have been too busy with other things in life for the past few years, so I haven't flown any of the drones for almost 3 years now. I do have all the best firmwares on the various drones (ability to fly where I want without worry of no-fly zones) and got really tired of the firmware games DJI was playing with hobbling older birds to make the newer products look more "attractive" so I learned to figure out the optimal firmware/app versions and just kept thing there to ensure maximum capabilities and viability for purpose.

I will say keep all the accessories maintained once a year is something of a chore, especially considering how I have not only the donres themselves, but lots of other necessities, such as 9 Android tablets(8.4" pairs, 10.2" pairs and even a 12.2"), 2 smartphones, manual focus puller accessories and other stuff on hand for use with everything. The Inspire setups are all dual controller and even can have a thord controller for focus pulling independently. I didn't know how effective it was until the focus puller came as part of a larger Osmo Pro package I purchased. After doing some intensive work with it for a few weeks I have learned that you either have the skill to maintain focus control (and with that it means you almost become "one" with the control and use it as an extension of your own ability to "focus in" on the subject at hand, which means you also have your hands full maintaining proper zoom and framing) or you don't. And if you do you fall into that specialized skill of cinematographer that most people don't associate with drones. I will say having three people working all together is pretty interesting and requires a LOT fo discipline (one pilot, one camera operator and a third focus puller) but is unmatched if you can get the combination right to pull it off. So much less work on the edit side and once you get "good" the cinematics rival any big studio. The X5R camera setup with a proper zoom for purpose makes it a reality, but the workflow on the output side is brutal to get good at if you don't do it all the time.

In all this time the only "losses" have been a pair of batteries for the Mavic Air that won't even start charging as of a few days ago. Not a real major loss either since both ended up having cell swelling at one point after I bought that Air setup used in 2021 with 5 batteries total.

 

[Brian Fist]

Well, I put the battery from the drone and the controller on the charger this morning. The battery showed 1 solid quadrant and the second one flashing when charging, so they most CERTAINLY do something to put the batteries into "pre-sale" state that is different than "hibernation". The battery would not "wake up" and show charge state until I hooked it up to a charger, so I highly doubt that the "self-hibernation" the batteries go into totally deactivates the BMS. I fully believe that the BMS is 100% deactivated in "pre-sale" state.

I have a brand new DJI Mavic 2 battery with three charges on it that depletes to BELOW where this battery was on initial charge.

I also charged the controller, which showed a 0% charge state when hooked up to the charger.

Now, I totally understand engineering, chemistry and all of that, but I would have to believe that there is a "static state" they can put a lithium battery into that allows for very long shelf-life and a very low loss of capacity. I would expect only the experts in the field to know what that exactly is and I would not doubt there is no way to get a battery back to that "state" once it is charged and the BMS activated.

The whole point being that I know the Fly More kit I have that is unopened is about a year newer than the Mavic 2 Zoom was and thus I am not in the least inclined to open it and charge the batteries from some sort of concern of "if they will work properly or not".

 

[slup]

Well, I put the battery from the drone and the controller on the charger this morning. The battery showed 1 solid quadrant and the second one flashing when charging, so they most CERTAINLY do something to put the batteries into "pre-sale" state...

New, customer unused batteries from DJI comes with a deactivated BMS to stop the parasitic draw a activated BMS will otherwise cause. The cells in these batteries are also charged to nominal voltage (3,7-3,8V= approx 50%) where the chemistry in the cells are nearly inactive & only suffers from a self discharge & aging which is typical for LiPo chemistry.

Your observation is very typical for a new battery which hasn't been customer charged for the first time & have been stored for a longer time... no LEDs light up when pushing the button before putting them on the charger for the first time (=deactivated BMS) & that it was 1 solid + 1 blinking indicate that the self discharge has lowered the voltage some, perhaps down to around 30%.

Once the battery have been "activated" by charging it for the first time, the BMS will stay active... until the cell voltage becomes very low during storage, likely way below 3,5V (on a DJI battery 3,5V=0%). Here the battery again doesn't light up the LEDs when pushing the button & the BMS can possibly be reactivated by charging the battery again... if the voltage haven't dropped down to damaging low levels (likely lower than 3,0V/cell), where a charge doesn't wake up the battery anymore.