Mavic Mini batteries - this could get expensive!!

[Detritalgeo]

Looks like the cells are Samsung INR-18650-25R. They are rated for 20A constant draw so not bad. They are rated based on a cycle of 4.2 - 2.5V so running them down won't hurt them but it does add to the cycle count which will reduce capacity.

If you want battery longevity, charge to only 4.10V and discharge to 3.20V (although this is not realistic). You will also notice on the attached image from the datasheet that the capacity loss rate is slightly higher in the early stages.

Oh well. As said above, never store these cells at 100% in storage.

 

[flynsign]

These are considered smart batteries so I would assume they would automatically go into storage mode after a given amount of time. Can anyone confirm this?

 

[Detritalgeo]

These are considered smart batteries so I would assume they would automatically go into storage mode after a given amount of time. Can anyone confirm this?

Hi,

They only have a basic protection IC that will prevent over-discharge, over-charge, over-current and cell imbalance. It does not look like there is the hardware needed to burn-off energy for storage mode. We will have to be more vigilant, but the good thing is that these won't balloon like the Lipo's..

Here is the image from RC-Geeks:

 

[mavicn00b]

Looks like the cells are Samsung INR-18650-25R. They are rated for 20A constant draw so not bad. They are rated based on a cycle of 4.2 - 2.5V so running them down won't hurt them but it does add to the cycle count which will reduce capacity.

If you want battery longevity, charge to only 4.10V and discharge to 3.20V (although this is not realistic). You will also notice on the attached image from the datasheet that the capacity loss rate is slightly higher in the early stages.

Oh well. As said above, never store these cells at 100% in storage.

You can't really fly them below 3.2v as the aircraft will autoland at %5% well before you can discharge further. They will only charge to 4.15v from stock charger so no chance of reaching 4.2v either.

 

[Detritalgeo]

You can't really fly them below 3.2v as the aircraft will autoland at %5% well before you can discharge further. They will only charge to 4.15v from stock charger so no chance of reaching 4.2v either.

Even better, looks like they are helping to promote greater lifespan that way. Still on us to reach proper storage voltage I guess.

 

[DanMan32]

These are considered smart batteries so I would assume they would automatically go into storage mode after a given amount of time. Can anyone confirm this?

Manual confirms batteries do not have any discharge feature.

 

[DanMan32]

You can't really fly them below 3.2v as the aircraft will autoland at %5% well before you can discharge further. They will only charge to 4.15v from stock charger so no chance of reaching 4.2v either.

I have never encountered the Mini try to auto land on low battery. Haven't tried with firmware released a few days ago.

 

[mavicn00b]

I have never encountered the Mini try to auto land on low battery. Haven't tried with firmware released a few days ago.

Skip to 23:00

 

[locutus40]

Lithium Ions in the MM are not nearly as robust as lithium polymer’s But they were necessary to keep the weight down.

its not the weight its the form factor think about it.. you got a brick thats 2 cells most bricks are big and wide its not very sexy and where you gunna put it.... youd have to make a tall drone.. so they went with lith ions

 

[Detritalgeo]

its not the weight its the form factor think about it.. you got a brick thats 2 cells most bricks are big and wide its not very sexy and where you gunna put it.... youd have to make a tall drone.. so they went with lith ions

Also it keeps the cost down, the 18650 cells are basically off the shelf so there is minimal cost to commissioning a unique pack of lipo cells. The MM remote also has a single 18650 cell instead of the Lipo pack found in the MP and MA remotes.

 

[Patroclus]

99% of the Time battery’s are not in use. Since these don’t have an automatic discharge function you should keep them stored not fully charged because it lowers the power storage capacity. And this is often the main reason why people are getting lower lifespan with their battery’s. Same applies also to notebooks when being charged all the time and other gadgets.

I store them at about 60-80%. The number of cycles is more or less irrelevant since you will not do more than 300 or more flights on each battery

Cheers
Alexander
(Munich)

Totally agree, abuse is the most likely reason batteries degrade. I'm sure DJI tested every which way with batteries and we got a fantastic light weight drone that flies for nearly half an hour and people are still not satisfied.... unbelievable.

 

[TDZHDTV]

Looks like the cells are Samsung INR-18650-25R. They are rated for 20A constant draw so not bad. They are rated based on a cycle of 4.2 - 2.5V so running them down won't hurt them but it does add to the cycle count which will reduce capacity.

If you want battery longevity, charge to only 4.10V and discharge to 3.20V (although this is not realistic). You will also notice on the attached image from the datasheet that the capacity loss rate is slightly higher in the early stages.

Oh well. As said above, never store these cells at 100% in storage.

How long would you suggest it is safe to store these batteries when fully charged? 2 days? A week? Not more than 10 days?

 

[Webcruise]

How long would you suggest it is safe to store these batteries when fully charged? 2 days? A week? Not more than 10 days?

The less the better. It depends how much capacity loss you are fine with having comfort.

I have been flying RC‘s for over 15 years and to be honest „for me“ the fly more combo this time (no automatic discharge function) does not make sense. I charge the battery same day or a day before flying and charge with an quick charge 3.0 (Qualcomm technology) Powerbank in between changing locations (motorcycle). The are also QC3.0 car adapter available.

I just don’t want the hassle of discharging I.e. two batteries if I have just used one.

Of course the long flight time of the MM made the decision easy

The reason for faster aging is the unbalance of the chemicals, that is why batteries are delivered not fully charged because they could be stored for several months before sale ( not the MM).

Cheers
Alexander
Munich

 

[DanMan32]

You can also use the batteries and hub as a powebank to bring down the SoC, including recharging the RC. Just be sure you either only have one in the 2 way hub at a time, or pull the one being used when it gets to the level you want.

 

[TDZHDTV]

The less the better. It depends how much capacity loss you are fine with having comfort.

I have been flying RC‘s for over 15 years and to be honest „for me“ the fly more combo this time (no automatic discharge function) does not make sense. I charge the battery same day or a day before flying and charge with an quick charge 3.0 (Qualcomm technology) Powerbank in between changing locations (motorcycle). The are also QC3.0 car adapter available.

I just don’t want the hassle of discharging I.e. two batteries if I have just used one.

Of course the long flight time of the MM made the decision easy

The reason for faster aging is the unbalance of the chemicals, that is why batteries are delivered not fully charged because they could be stored for several months before sale ( not the MM).

Cheers
Alexander
Munich

I’m also experimenting with QC 3.0 powerbanks, as I hike and mountain bike and are looking for a multi day solution for charging.

 

[TDZHDTV]

You can also use the batteries and hub as a powebank to bring down the SoC, including recharging the RC. Just be sure you either only have one in the 2 way hub at a time, or pull the one being used when it gets to the level you want.

It’s a pity the hub wasn’t intelligent enough to discharge all batteries to the same level when charging ancillary equipment

 

[DanMan32]

It’s a pity the hub wasn’t intelligent enough to discharge all batteries to the same level when charging ancillary equipment

Agreed. But then someone would complain that now all his batteries are less than 100% so he can't fly, when only one battery would suffice for the ancillary equipment.

 

[Martinjsto]

Seem from my research if you try to swap out batteries for 18650 3000 or 3400 when you disconnect the old batteries from the chipset it locks the board. I'm not 100% on this but tje B.O.B on YouTube is a small pcb made for this reason.now I was thinking what if I solder a two pack 12650 via small wires pos to pos neg to neg on battery pack b4 unsoldering old battery maintaining voltage to chip then theoretically unsoldering old Replace with new unsolder wires. Bobs your uncle. Thoughts

 

[Bearsfan77]

They are Samsung 18650 in the mavic mini they are green in color.

 

[Kenh6468]

You can also use the batteries and hub as a powebank to bring down the SoC, including recharging the RC. Just be sure you either only have one in the 2 way hub at a time, or pull the one being used when it gets to the level you want.

If you use the charge hub as a powerbank to discharge a battery how do you know when it is down to 60% power to remove it? Are there a certain number of charging indicator LEDs lit and if so then how many lit indicate the battery is charged to 60%?