dji mavic pro batteries issue

[jofer]

Hello, i have this two batteries, i bought the dji mavic pro with 3 batteries, and the seller told me that 2 of them didn't work, i charged them and connected to the drone:
battery 1:
3.86V 3.99V 4.23V
voltage 12.09v
temperature 23.3ºC
product date: 2017-5
times charged: 12
current status
cell broken

battery 2:
4.20V 4.06V 4.30V
voltage 12.54v
temperature 22.6ºC
product date: 2017-5
times charged:15
current status
cell broken

i searched at google about this type of issues.
it's normal that a battery with 12 and 15 times charged get faulty?!!
how can i fix this?

thanks and sorry my english

 

[brett8883]

Hello, i have this two batteries, i bought the dji mavic pro with 3 batteries, and the seller told me that 2 of them didn't work, i charged them and connected to the drone:
battery 1:
3.86V 3.99V 4.23V
voltage 12.09v
temperature 23.3ºC
product date: 2017-5
times charged: 12
current status
cell broken

battery 2:
4.20V 4.06V 4.30V
voltage 12.54v
temperature 22.6ºC
product date: 2017-5
times charged:15
current status
cell broken

i searched at google about this type of issues.
it's normal that a battery with 12 and 15 times charged get faulty?!!
how can i fix this?

thanks and sorry my english

Those are both bad throw them away in an environmentally friendly way. I know places like Best Buy have recycling stations at the entrance to get rid of things like that.

As to if it’s normal, it really just depends on how they were handled and shipped. They are very temperature sensitive.

 

[mnis]

Hello, i have this two batteries, i bought the dji mavic pro with 3 batteries, and the seller told me that 2 of them didn't work, i charged them and connected to the drone:
battery 1:
3.86V 3.99V 4.23V
voltage 12.09v
temperature 23.3ºC
product date: 2017-5
times charged: 12
current status
cell broken

battery 2:
4.20V 4.06V 4.30V
voltage 12.54v
temperature 22.6ºC
product date: 2017-5
times charged:15
current status
cell broken

i searched at google about this type of issues.
it's normal that a battery with 12 and 15 times charged get faulty?!!
how can i fix this?

thanks and sorry my english

Are the batteries deformed or are there cracks in the housing?
Look at the product label, is it still flat?

If everything is OK, you could try the following:
Try to discharge the batteries until they turn themselves off. For this you can empty the batteries directly in the Mavic. Turn the battery ON, and wait until the Mavic goes off by itself. Then recharge the battery. Repeat this procedure 2 to 3 times and check the values in DJI GO.

If a battery warms abnormally high during the cycles at around 20 to 25 degrees Celsius ambient temperature (> 45 degrees Celsius), immediately stop the procedure and discard the battery for disposal.

Also, you should be present throughout the procedure to be able to intervene immediately in case of problems.

And if the described procedure is not applicable, or if there are still large differences (> 0.03 volts) in the cell voltages, then you can no longer trust the battery!

Edit:
The previous owner may have used the sport mode in flight very often. Or the batteries were too often stored for more than ten days in full condition ...

 

[jofer]

thanks for the answer. i will try to discharge the batteries.

i think the previous owner may have stored for more than ten days in full condition. because the working battery has more than 40 times charged., and this two they have low number of times charged.

 

[mnis]

thanks for the answer. i will try to discharge the batteries.

i think the previous owner may have stored for more than ten days in full condition. because the working battery has more than 40 times charged., and this two they have low number of times charged.

Be careful when cycling. Keep in mind that an out of control lithium battery can not be stopped, it will completely decompose under high heat and smoke.

And report please about success and failure

 

[jofer]

i discharged one of the batterys, and this happened:
3.84v 3.96v 4.2v 11.99v 21.7ºC---i didn't check the % of battery
3.71v 3.76v 3.9v 11.39 30.1ºC----43%
3.65v 3.72v 3.83v 11.22v 31.4ºC----26%
3.63v 3.7v 3.8v 11.11v 31.9ºC----15%
3.43v 3.67v 3.78v 10.92v 32.6ºC----9%
3.2v 3.66v 3.77v 10.66v 32.9ºC---5% and a few seconds after i saw this numbers the drone shuts down.

what you all think? should i try to charge the battery?

 

[mnis]

i discharged one of the batterys, and this happened:
3.84v 3.96v 4.2v 11.99v 21.7ºC---i didn't check the % of battery
3.71v 3.76v 3.9v 11.39 30.1ºC----43%
3.65v 3.72v 3.83v 11.22v 31.4ºC----26%
3.63v 3.7v 3.8v 11.11v 31.9ºC----15%
3.43v 3.67v 3.78v 10.92v 32.6ºC----9%
3.2v 3.66v 3.77v 10.66v 32.9ºC---5% and a few seconds after i saw this numbers the drone shuts down.

what you all think? should i try to charge the battery?

Yes, recharge the battery and repeat the discharge process. If the cell difference does not improve significantly after two to three cycles, then this battery is defective.

 

[brett8883]

i discharged one of the batterys, and this happened:
3.84v 3.96v 4.2v 11.99v 21.7ºC---i didn't check the % of battery
3.71v 3.76v 3.9v 11.39 30.1ºC----43%
3.65v 3.72v 3.83v 11.22v 31.4ºC----26%
3.63v 3.7v 3.8v 11.11v 31.9ºC----15%
3.43v 3.67v 3.78v 10.92v 32.6ºC----9%
3.2v 3.66v 3.77v 10.66v 32.9ºC---5% and a few seconds after i saw this numbers the drone shuts down.

what you all think? should i try to charge the battery?

Yea try it but you should wait till it’s cool and keep a close eye on the whole time. As a matter of last resort, try flashing the firmware even though it’s the latest version. Something seems off about the % indicator it’s giving you.

 

[mnis]

Yea try it but you should wait till it’s cool and keep a close eye on the whole time. As a matter of last resort, try flashing the firmware even though it’s the latest version. Something seems off about the % indicator it’s giving you.

The display of the percentage charge is initially not relevant, and without multiple balancing probably very inaccurate ...

In the last third of the charging process, the balancing takes place. The balancer of the battery will try to reduce the cell difference. If the balancer fails to balance because a cell is defective, it will stop charging prematurely.

Since there is also temperature monitoring, there should be no danger during charging.

Nevertheless, attention should be paid.

You have not told in what optical state the batteries are, so I assume that everything is OK and the attempt to make a few cycles makes sense.

 

[mnis]

It is also possible that the status "cell broken" can not be cleared if the controller of the battery has set it once. This would be an internal security feature that may not be bypassed by the user. So I see the only way to give some cycles, to see if an improvement can occur ...Good luck...

 

[brett8883]

The display of the percentage charge is initially not relevant, and without multiple balancing probably very inaccurate ...

In the last third of the charging process, the balancing takes place. The balancer of the battery will try to reduce the cell difference. If the balancer fails to balance because a cell is defective, it will stop charging prematurely.

Since there is also temperature monitoring, there should be no danger during charging.

Nevertheless, attention should be paid.

You have not told in what optical state the batteries are, so I assume that everything is OK and the attempt to make a few cycles makes sense.

When you have a damaged cell anything can happen. We don’t even know if the temperature algorithm is working and if it can measure individual cells or just the overall ambient temperature. For all we know the software is faulty which seems pretty possible given it allowed such a large unbalancing of the cells. Besides reflashing can’t really hurt.

 

[mnis]

When you have a damaged cell anything can happen. We don’t even know if the temperature algorithm is working and if it can measure individual cells or just the overall ambient temperature. For all we know the software is faulty which seems pretty possible given it allowed such a large unbalancing of the cells. Besides reflashing can’t really hurt.

I have no contradiction to your statement regarding firmware

It is only a single temperature sensor that monitors the entire battery pack. There may be an additional temperature sensor on the PCB...

The software worked correctly so far, and marked the cell package as "cell broken".

 

[Maui Jeff]

thanks for the answer. i will try to discharge the batteries.

i think the previous owner may have stored for more than ten days in full condition. because the working battery has more than 40 times charged., and this two they have low number of times charged.

This is the first I've heard about not storing the batteries fully charged. Please explain.

 

[brett8883]

This is the first I've heard about not storing the batteries fully charged. Please explain.

You don’t want to store the batteries fully charged for more than a few days but 24 hours is preferable to maintain better battery life capacity. If lithium ion batteries are laft at full capacity for an extended period of time it can damage or distroy the cells.

The Mavic batteries have a built in computer chip that will begin to discharge the battery after 10 days of disuse to fend against this but DJI recommends manually discharging the batteries down to 50% if you won’t be using the batteries for more than 24 hours to achieve “highest happiness.[sic].”

 

[Maui Jeff]

You don’t want to store the batteries fully charged for more than a few days but 24 hours is preferable to maintain better battery life capacity. If lithium ion batteries are laft at full capacity for an extended period of time it can damage or distroy the cells.

The Mavic batteries have a built in computer chip that will begin to discharge the battery after 10 days of disuse to fend against this but DJI recommends manually discharging the batteries down to 50% if you won’t be using the batteries for more than 24 hours to achieve “highest happiness.[sic].”

Thank you very much! I've been doing it completely wrong - charging my batteries when I get home so that they're ready to go next time. I have noticed the self discharging tho - which seemed excessive. Now I know why!

 

[Ilovepe]

Are the batteries deformed or are there cracks in the housing?
Look at the product label, is it still flat?

If everything is OK, you could try the following:
Try to discharge the batteries until they turn themselves off. For this you can empty the batteries directly in the Mavic. Turn the battery ON, and wait until the Mavic goes off by itself. Then recharge the battery. Repeat this procedure 2 to 3 times and check the values in DJI GO.

If a battery warms abnormally high during the cycles at around 20 to 25 degrees Celsius ambient temperature (> 45 degrees Celsius), immediately stop the procedure and discard the battery for disposal.

Also, you should be present throughout the procedure to be able to intervene immediately in case of problems.

And if the described procedure is not applicable, or if there are still large differences (> 0.03 volts) in the cell voltages, then you can no longer trust the battery!

Edit:
The previous owner may have used the sport mode in flight very often. Or the batteries were too often stored for more than ten days in full condition ...

What does flying a lot in sport mode have to do with the battery life?

 

[mnis]

What does flying a lot in sport mode have to do with the battery life?

Good question, but first my basic opinion about the sport mode:
The sport mode in the entire Mavic series is almost total nonsense. They are primarily drones for photo / video, not for speed fanatics. For racing or aggressive flying, there are special drones that were built for this purpose and are therefore actually suitable for racing or aerobatics. As an exception, I see only the use of the sport mode in the fight against wind, perhaps to be able to return back to HomePoint.

The Answer:
Intense use of the Sport mode can damage or destroy the cells of the Mavic battery pack. Even a 20-minute flight in normal mode makes the batteries near the end of their capacity about 50 to 55 degrees Celsius hot. Those who exaggerate sports mode risk the loss of battery and mavic.

It is therefore important to take care not to bring the battery pack in the critical temperature range of 60 degrees.

If you want to fly in sports mode, you should go back to normal mode if you drop below 50 percent battery capacity. Sport mode is just as problematic as storing a fully charged Mavic battery for extended periods of time...

 

[BossBob]

Thank you very much! I've been doing it completely wrong - charging my batteries when I get home so that they're ready to go next time. I have noticed the self discharging tho - which seemed excessive. Now I know why!

Odd that when I reduced the time to self discharge of my 2 year old batteries to 3 days and ended up charging them every weekend I ended up with a puffed battery! Now I fly to about 30% and recharge on Friday night ready for the weekend. A real pain if there is something that needs drone video NOW.

 

[brett8883]

Good question, but first my basic opinion about the sport mode:
The sport mode in the entire Mavic series is almost total nonsense. They are primarily drones for photo / video, not for speed fanatics. For racing or aggressive flying, there are special drones that were built for this purpose and are therefore actually suitable for racing or aerobatics. As an exception, I see only the use of the sport mode in the fight against wind, perhaps to be able to return back to HomePoint.

The Answer:
Intense use of the Sport mode can damage or destroy the cells of the Mavic battery pack. Even a 20-minute flight in normal mode makes the batteries near the end of their capacity about 50 to 55 degrees Celsius hot. Those who exaggerate sports mode risk the loss of battery and mavic.

It is therefore important to take care not to bring the battery pack in the critical temperature range of 60 degrees.

If you want to fly in sports mode, you should go back to normal mode if you drop below 50 percent battery capacity. Sport mode is just as problematic as storing a fully charged Mavic battery for extended periods of time...

I respect your opinion and your caution but my experience is a bit different. When you look at the current discharge(the amount of battery being used at any given moment) you’ll see something that may seem strange. The amount of current used to hover and fly slow is often more power than flying fast. Yes braking and accelerating quickly use up a good amount of current but probably not as much as you’d think. It turns out it’s more complicated than you’d think.

When in sport mode you can change your mini map into the “radar” attitude gauge thing. This will show you the % of the maximum current discharge you are currently using. There is a point on the gauge where it turns from green to blue. Right at this point it indicates most efficient use of power. If you are concerned about using up too much battery you can check this to know you aren’t over discharging the battery. You can also keep an eye on the RPMs on the remote. This is an average of all 4 motors and is a good indicator of the amount of current being used. Generally speaking the most efficient average motor speed is 650 or 6500 RPMs. This is for the Macic Pro I don’t know about the Mavic 2.

DJI did a good job of designing the Mavic to be very forgiving when it comes to this and the Mavic is actually much more powerful and much faster than the software allows. This doesn’t mean you should fly balls to the wall the whole time but I wouldn’t be overly worried about it. The Mavic will let you know if you are harming it before you can do any real damage. The easiest way to do that though in case you are wondering is to full sticks up and forward. It takes a ton of current to ascend at max speed and fly forward at max speed. Try to limit doing that I think you’ll be fine in sport mode.

 

[brett8883]

Odd that when I reduced the time to self discharge of my 2 year old batteries to 3 days and ended up charging them every weekend I ended up with a puffed battery! Now I fly to about 30% and recharge on Friday night ready for the weekend. A real pain if there is something that needs drone video NOW.

Yea the self-discharging is really just a fail-safe in case you forget to manually discharge them every once in awhile. I don’t think it was really meant to be relied on as an alternative to manual discharge.

Interesting you say this because on the Mavic 2 they removed the feature to change the standard 10 days to self-discharge. I have been wondering why so maybe it’s just best to leave it at 10 days. Thanks for the heads up!