How to prolong the life of your Batteries.

[Xcel]

A fully charged Mavic battery sits at 4.28v per cell according to the DJI app.

 

[Kilrah]

So any thoughts on whether the "advanced" charging hub for Mav batteries would sig. shorten the battery life since it's charging faster (esp with P4 power adapter)?

It has the ability to charge faster when using the P4 charger, but will charge the same speed with the Mavic charger. Your call to choose the most appropriate way for the situation (go fast knowing you'll likely shorten the life of your battery a tad due to 2C charging but accept it because you're in a hurry, or charge normally when you have time).

You can already charge faster with the car charger (logic likely being that DJI considered that if you need to charge on the move it's becasue you're short and need it ASAP, again at the acceptable expense).

 

[CyberNate]

You don't have to worry about prolonging the battery life. DJI is already doing it for you.

Here is my post from another thread regarding increasing capacity, but I've also touched on how DJI manages the battery for longer lifespan in charge cycles:

"If you have a spot welder, you can replace the cells with higher capacity Panasonic 18650GA cells. They are rated at 3500 MAh. In a 3s2p pack like the mavic has that is 7000MAh and 80WHr; however I think that's likely what they already have in there or similar. I believe DJI under utilizes the capacity for pack longevity. The 100% you see reported in the app and controller is more like 80% of the cells and likewise, 0% is really 20% left in the cell. The mavic electronics would get wonky if they really tried to use ALL the battery, where voltage drops off quickly under 10%. The pack is rated at 11.4V and 3850MAh. If you only charge to 80% and discharge to 20% the batteries last MUCH longer with more recharge cycles available and more reliability. Electric cars do the same thing, only using a small window of the capacity and gradually using more percentage of the battery over time as the lithium cells deteriorate. As time goes by, the battery producers figure out ways to get more energy density out of the cells to satisfy the electric car industry. We benefit with the new DJI models when they leverage the latest cells in the battery packs."

The one thing you CAN do is to let the cells cool down BEFORE changing again. Heat is the one thing that can decrease cell life.

Edit: Regarding capacity, it looks like DJI is probably using the cheaper 3200MAh cells. So that means the 3s2p back has 6400MAh potential capacity. If you only change to 80% and down to 20% you utilize 60% of the pack. 6400MAh x 60% = 3840MAh which is the precise rating of the battery pack. This means one could replace the cells with Panasonic 18650GA cells rated at 3500MAh and get 7000MAh x 60% = 4200MAh. I could easily see extended packs being offered in the future that are the same dimensions as stock.

Actually I'm incorrect. DJI is using Lipo, not 18650 cells. You can see it here in a teardown:

DJI Mavic Battery Disassemble

 

[Kate]

my 2 sense. Your batteries will out live your drone

can you imagine getting the 'fly more pack' and writing your mavic off
that would sting

 

[CyberNate]

can you imagine getting the 'fly more pack' and writing your mavic off
that would sting

Yes, that almost happened to me. Crashed it in the first 2 weeks, but they replaced it for only $189. I was really surprised. It had a lot of damage. Must have been a new assessor.

 

[dangerm0us]

A fully charged Mavic battery sits at 4.28v per cell according to the DJI app.

That's strange! I've never seen it that high on mine?? I saw 1 cell at 4.22 and the other 2 cells at 4.21 each with a battery that was fresh (well, I powered up the Mavic, the app, etc so it was powered on 2 mins tops).

Here is breakdown of LiPO voltages:

4.20v = 100%
4.03v = 76%
3.86v = 52%
3.83v = 42%
3.79v = 30%
3.70v = 11%
3.6?v = 0%

4.28V is definitely an overcharge and that WILL result in cell damage. Are you doubly sure about that number????

 

[CyberNate]

That's strange! I've never seen it that high on mine?? I saw 1 cell at 4.22 and the other 2 cells at 4.21 each with a battery that was fresh (well, I powered up the Mavic, the app, etc so it was powered on 2 mins tops).

Here is breakdown of LiPO voltages:

4.20v = 100%
4.03v = 76%
3.86v = 52%
3.83v = 42%
3.79v = 30%
3.70v = 11%
3.6?v = 0%

4.28V is definitely an overcharge and that WILL result in cell damage. Are you doubly sure about that number????

Yes, that meter must be off. 4.2V should be the maximum for both Lithium Ion and Lithium Polymer batteries.

 

[Robbyg]

The 2170 is the next generation of batteries for the Mavic. I would not be surprised if it's released with the Mavic2 and it certainly will be backward compatible with the Mavic Pro.

Double the flying time, Sweeeeet!!!

Rob

 

[Dragonfly]

First off, the Mavic Battery is a lithium Polymer (lipo) NOT lithium ion. It full charge capacity is 4.20 volts per cell.
Second, you have no need to worry about matinence on these batterys as DJIs circuitry in the battery take care of it.
They are high C rating high discharge batteries and can be charged happily at 2C and are charged at 1C 3500mha at 3 amps = 1hour 10 minutes. Or less if using fast care charger.
Also DJI incorporates an automatic discharge in the battery to discharge to about 65% capacity for storage after set number of days (this can be set in app) if battery is not used.
So if you charge and don't fly your battery will auto discharge to storage capacity for longetivety.
Just remember to top up charge before use if set for two days. Think default is fiur days (correct me if wrong).

Sent from my SM-G900I using MavicPilots mobile app

 

[dangerm0us]

First off, the Mavic Battery is a lithium Polymer (lipo) NOT lithium ion. It full charge capacity is 4.20 volts per cell.
Second, you have no need to worry about matinence on these batterys as DJIs circuitry in the battery take care of it.
They are high C rating high discharge batteries and can be charged happily at 2C and are charged at 1C 3500mha at 3 amps = 1hour 10 minutes.
Also DJI incorporates an automatic discharge in the battery to discharge to about 65% capacity for storage after set number of days (this can be set in app) if battery is not used.
So if you charge and dint fly your battery will auto discharge to storage capacity for longetivety.
Just remember to top up charge before use if set for two days. Think default is fiur days (correct me if wrong).

Sent from my SM-G900I using MavicPilots mobile app

Yes I mentioned that particular point a few posts ago about the batteries and their auto discharge to storage voltage. I believe the default is 10 days.

Where did you see the info about the C rating for discharge?

 

[Dadcat]

4.28V is definitely an overcharge and that WILL result in cell damage. Are you doubly sure about that number????

Full charge voltage of the Mavic batteries is actually 4.35V per cell. DJI started using this newer chemistry Lithium technology almost 2 years ago with the Phantom 3. I didn't believe it myself until I checked the no-load charge of my P3 batteries and found they actually did charge to 17.4V (4.35 x 4).

I don't know how to measure the Mavic battery voltage outside the craft, but the 4.28 to 4.30V that I'm seeing when I first power up the Mavic is consistent with what the P3 reported with new batteries. You'll never see the actual full charge voltage because of the power draw of the idling bird.

The output of the charger is spec'd at 13.05V, consistent with 4.35V per cell. Your grandaddy's LiPo chargers would never output that high a voltage, at least on purpose.

Anyway- the higher than traditional LiPo voltages being reported are normal and expected. They do not indicate an overcharge.

 

[Robbyg]

It seems like 2017 is going to be a good year for higher capacity batteries. In response to Panasonic and Tesla's 2170 I read that Samsung is coming out with a battery that is also a huge leap forward (hopefully without exploding).
I have no doubts that DJI will be using one of those models in their 2018 battery packs. It would be corporate suicide if they don't take advantage of it because other drone companies will.
I expect flight times to be hitting near the one hour mark with the new 2018 drones.

 

[Egika]

Why would you think that there are cylindrical 18650 cells in the Mavic's battery pack?
Without having opened one, I highly doubt this. It would just use up so much space between the cells.
The big advantage of LiPo batteries is that they can be built to nearly every shape.
I would expect 3 cubical cells in the battery pack like these:

Whatever Panasonic or others build for consumer electronics has not much to do with the one in the Mavic - except for the chemical principle.

 

[dangerm0us]

Full charge voltage of the Mavic batteries is actually 4.35V per cell. DJI started using this newer chemistry Lithium technology almost 2 years ago with the Phantom 3. I didn't believe it myself until I checked the no-load charge of my P3 batteries and found they actually did charge to 17.4V (4.35 x 4).

I don't know how to measure the Mavic battery voltage outside the craft, but the 4.28 to 4.30V that I'm seeing when I first power up the Mavic is consistent with what the P3 reported with new batteries. You'll never see the actual full charge voltage because of the power draw of the idling bird.

The output of the charger is spec'd at 13.05V, consistent with 4.35V per cell. Your grandaddy's LiPo chargers would never output that high a voltage, at least on purpose.

Anyway- the higher than traditional LiPo voltages being reported are normal and expected. They do not indicate an overcharge.

No kidding. Well you learn something every day! Thanks for the info. I will have a hunt around for more info on that new battery chemistry you referred to. I thought Lithium cells only went to 4.2V and that was gospel.

 

[Wombat55]

The one thing you CAN do is to let the cells cool down BEFORE changing again. Heat is the one thing that can decrease cell life.

I think that this is probably the one major thing that most Mavic owners should remember. I never recharge the Mavic's battery immediately after a flight. Just set it aside and let it cool down and recharge it later.

 

[Robert Granata]

Is the battery maintenance schedule on HealthyDrones a good one to follow? They recommend to drain the battery to 8% every 20 recharges.

 

[Dw911]

Is the battery maintenance schedule on HealthyDrones a good one to follow? They recommend to drain the battery to 8% every 20 recharges.

Probably debatable if it makes any real difference.
Tbh I been using rechargeable batteries for many years, found they always last longer than you think in respect of when they are no longer able to hold a decent amount of energy for the application you have have them in.
As they have got cheaper year on year, and are often a small amount compared to the cost of what you put then I.E the mavic.
I no longer worry to much about it, I'd rather have the batteries fully charged ready to go, much more fun to be flying than waiting for batteries to charge cos it may get me a couple of extra charge cycles over the lifetime of the battery. I just consider the Mavic batteries to be a consumable.
Life's to short to be worrying about batteries (other than from a safety perspective)

In the UK at least Luckily or unluckily depending how you veiw it, one mavic battery equates to one medium sized car tankful of petrol/Diesel.

 

[willhay555]

I've yet to understand what duration is considered in storage.

A week, a month, what?

At what point should my batteries by part charged to keep them in best condition?

Sent from my D6603 using MavicPilots mobile app

 

[Kilrah]

More than a week is usally an accepted duration - and the time after which Mavic battery will auto-discharge to storage voltage by default.

 

[Rich Sugden M.D.]

Don't know about the Mavik batteries, but I had $600 worth of Inspire batteries get discharged to destruction in about 6 months of storage ... and the only thing that could have discharged them was the DJI "monitoring circuit" inside the battery .. as they were not connected to anything while being stored ... and were put away fully charged. I have hundreds of LiOn and LiPo batteries in everything from ATV's to cameras to RC helis, and many drones, and NONE of them have ever had problems w. over-discharged batteries ... even after years of storage ... So I suspect the DJI monitoring circuitry is the culprit .... Once LiOn/LiPo batteries are discharged beyond a certain point they are destroyed forever .. they cannot be resurrected like NiCad or NMH batteries...