Overcharge a Mavic Pro 2 battery??

[DougMcC]

Just this week I read a post about battery maintenance with the caution to “ avoid overcharging the battery”. While I may be wrong, I thought that the circuitry in the Mavic 2 Pro battery stops the charging cycle when a full charge cycle is completed. All the lights then go out and that battery remains cool. I have assumed that battery charging has ceased and thus overcharging is not possible. So, I would appreciate clarification about this issue and I will mend my errant ways. I do understand that storage charge should be somewhere around 60-80%.

 

[Meta4]

Just this week I read a post about battery maintenance with the caution to “ avoid overcharging the battery”. While I may be wrong, I thought that the circuitry in the Mavic 2 Pro battery stops the charging cycle when a full charge cycle is completed. All the lights then go out and that battery remains cool. I have assumed that battery charging has ceased and thus overcharging is not possible. So, I would appreciate clarification about this issue and I will mend my errant ways. I do understand that storage charge should be somewhere around 60-80%.

You are correct about the charger.
The charger doesn't allow you to overcharge the battery.
You could leave it plugged in for a week but once the battery is properly charged the charging stops.

Storage charge is down around 50%

 

[DougMcC]

Thank you. That is what I thought from previous reading. So leaving it overnight on the charger should be fine if you plan to take it out in the AM and fly. Longer time storage should be around 50% charge (estimated).

 

[The RAPier]

It needs to be said that a charging Lipo battery should never be left unattended. They have burst into flame in some cases. Search the site for battery fire and insurance claims and other safety items.
And happy flying.

 

[GadgetGuy]

It needs to be said that a charging Lipo battery should never be left unattended. They have burst into flame in some cases. Search the site for battery fire and insurance claims and other safety items.
And happy flying.

While that may be a valid concern with unknown batteries, it is unnecessary with DJI batteries on the DJI charger, as long as the batteries are not known to be damaged. Never seen or heard of any DJI battery busting into flames while being charged. It would be all over the internet if they did! However, if you can't sleep while charging your DJI batteries, feel free to babysit them.

 

[DanMan32]

All legitimate Lipo chargers will always stop charging when the battery is fully charged. The potential issue is putting a fully charged battery back on charge. The charger connected to a "dumb" pack can't tell if the battery is charged until it goes through the constant voltage charging phase (last 20%). If you do that too often, it may become overcharged.

Smart batteries like DJI batteries store and know the recent charge state and so won't let it be charged again until you actually use it. You can't really overcharge them.

 

[WithTheBirds]

While that may be a valid concern with unknown batteries, it is unnecessary with DJI batteries on the DJI charger, as long as the batteries are not known to be damaged. Never seen or heard of any DJI battery busting into flames while being charged. It would be all over the internet if they did! However, if you can't sleep while charging your DJI batteries, feel free to babysit them.

As a general observation I fear you may have missed the point that there is nothing special about DJI batteries that might provide immunity from the known performance of LiION chemistry. In this regard they are no different to any other reasonably engineered battery containing HV LiPO cells.

While I haven’t seen anything recently (I haven’t been actively searching) I recall at least two seperate incidents (Inspire 1 and P3P) where it is claimed the batteries caught fire with spectacular results during charge (within the confines of domestic premises).

Statistically the chance of a problem seems to be so small it’s almost not worth worrying about. Nonetheless my batteries get charged outdoors with safe clearance to combustible material when unattended.

 

[Dragonfly]

What people are missing with DJI mavic 1/2 batteries is the charger is only a 13.8 volt suply voltage, it is not a charger. All the charging circuit and smart charge chip is contained inside each and every battery.
Each battery monitors and records each cell status and balance charges each cell back to full capacity. The chip monitors and remembers charge status/temputure etc and once fully charged even if charger voltage is reapplied it will not charge or even start to charge unless the pack has dropped at leased 10+%. No way can a pack be overcharged.
Also manufacture reference of all lipo cells storage capacity is 65-75% for optimal storage.

 

[GadgetGuy]

As a general observation I fear you may have missed the point that there is nothing special about DJI batteries that might provide immunity from the known performance of LiION chemistry. In this regard they are no different to any other reasonably engineered battery containing HV LiPO cells.

While I haven’t seen anything recently (I haven’t been actively searching) I recall at least two seperate incidents (Inspire 1 and P3P) where it is claimed the batteries caught fire with spectacular results during charge (within the confines of domestic premises).

Statistically the chance of a problem seems to be so small it’s almost not worth worrying about. Nonetheless my batteries get charged outdoors with safe clearance to combustible material when unattended.

I haven't missed your point, but the quality of the batteries used by DJI and the smart battery technology employed on all DJI batteries and the number of them in circulation gives us a large sample size from which to make comparisons and draw empirical conclusions. Current DJI batteries are not catching fire during normal charging on DJI chargers. Statistically, it's not a valid concern, as you apparently agree. Two lone reported claims of ancient DJI batteries manufactured over 4 years ago, of unknown condition, charged by unknown chargers, are hardly relevant to today. That being said, if you sleep better charging them outside, no harm will come from your abundance of caution. Just make sure they are out of the rain, and not frying in the heat of the sun!

 

[GadgetGuy]

What people are missing with DJI mavic 1/2 batteries is the charger is only a 13.8 volt suply voltage, it is not a charger. All the charging circuit and smart charge chip is contained inside each and every battery.
Each battery monitors and records each cell status and balance charges each cell back to full capacity. The chip monitors and remembers charge status/temputure etc and once fully charged even if charger voltage is reapplied it will not charge or even start to charge unless the pack has dropped at leased 10+%. No way can a pack be overcharged.
Also manufacture reference of all lipo cells storage capacity is 65-75% for optimal storage.

Thanks for clarifying that the charging circuit and the smart charge chip used in DJI batteries deserves a lot of the credit for the safe charging of DJI batteries!

 

[WithTheBirds]

I haven't missed your point, but the quality of the batteries used by DJI and the smart battery technology employed on all DJI batteries and the number of them in circulation gives us a large sample size from which to make comparisons and draw empirical conclusions. Current DJI batteries are not catching fire during normal charging on DJI chargers. Statistically, it's not a valid concern, as you apparently agree. Two lone reported claims of ancient DJI batteries manufactured over 4 years ago, of unknown condition, charged by unknown chargers, are hardly relevant to today. That being said, if you sleep better charging them outside, no harm will come from your abundance of caution. Just make sure they are out of the rain, and not frying in the heat of the sun!

You seem to be still suggesting DJI batteries have superior quality cells. They are good. No question. They aren’t exclusive to DJI though. The smart battery technology is the same TI impedance track and fuel gauging SOC that many manufacturers use. No manufacturer produces a LiION battery that immune from catching fire. That is all I am saying. And yes the evidence does suggest the chance of a fire while charging is very low. I’m not prepared to take the chance however. I have seen with my own eyes what happens when HV LiPO’s throw a leg out of bed. Admittedly I did deliberately cause them- because I was curious.

I don’t understand how you might possibly say that no recent DJI battery has had an issue.

 

[GadgetGuy]

You seem to be still suggesting DJI batteries have superior quality cells. They are good. No question. They aren’t exclusive to DJI though. The smart battery technology is the same TI impedance track and fuel gauging SOC that many manufacturers use. No manufacturer produces a LiION battery that immune from catching fire. That is all I am saying. And yes the evidence does suggest the chance of a fire while charging is very low. I’m not prepared to take the chance however. I have seen with my own eyes what happens when HV LiPO’s throw a leg out of bed. Admittedly I did deliberately cause them- because I was curious.

I don’t understand how you might possibly say that no recent DJI battery has had an issue.

Never said they have superior quality battery cells. Just good quality cells. Nothing is immune from everything. Anything is possible. However, the charging is controlled by the smart battery technology, which is specifically designed to prevent the very concerns you have.

I challenge you to find a single verified incident of an undamaged recent DJI battery catching fire during normal charging on a DJI charger within the battery warranty. Find one, and I will add an asterisk to my statement. Current DJI batteries are not catching fire during normal charging on DJI chargers. I don't even find the ancient two claims you referred to above credible, without first knowing more about the details. Even one verified report among the millions of DJI batteries in use would point more towards a freak perfect storm accident that cannot be prevented, like an unknowingly abused battery, with hidden damage, and a defective smart battery chip, charged on a defective charger.

Sometimes, your number just comes up. Planes crash. People die. Should we drive instead? More people die driving than flying. Living life is an assumption of the risk of injury or death. Flying drones comes with all kinds of risks. Charging the batteries is the least of them. I had a P3P, with 500g of attached external batteries, (attached but unfortunately not connected on that test flight) free fall from 215 feet directly above me, when the internal battery shut off in flight, while displaying 85% remaining in DJI GO. Fortunately, it landed 10 feet away from me, rather than on top of my head, or I wouldn't be here to write about it. Stuff happens. We have to assume some level of risk to fly drones. I naively assumed I was safer on the ground flying vicariously, instead of inside a piloted aircraft that could crash with me in it. Not true!

If I charged every LiPo battery I own in the various drones, remotes, cameras, flashes, Segway Minis, Segway Scooters, various eBikes, supplemental lights, horns, GPS devices, iPads, and iPhones outside, I would need a full double car carport! I charge them all indoors for convenience and security, unattended, but remove them when they are charged. I accept the risk.

Do what you feel you need to, to feel safe, as will I, and let's both hope that is enough.

 

[DanMan32]

Correction: M2 batteries are 4S with charging voltage being 17v.

Under warranty isn't really a good criteria since it's only 6 months. We usually keep our quads for 1-2 years with original batteries.

 

[WithTheBirds]

Never said they have superior quality battery cells. Just good quality cells. Nothing is immune from everything. Anything is possible. However, the charging is controlled by the smart battery technology, which is specifically designed to prevent the very concerns you have.

I challenge you to find a single verified incident of an undamaged recent DJI battery catching fire during normal charging on a DJI charger within the battery warranty. Find one, and I will add an asterisk to my statement. Current DJI batteries are not catching fire during normal charging on DJI chargers. I don't even find the ancient two claims you referred to above credible, without first knowing more about the details. Even one verified report among the millions of DJI batteries in use would point more towards a freak perfect storm accident that cannot be prevented, like an unknowingly abused battery, with hidden damage, and a defective smart battery chip, charged on a defective charger.

Sometimes, your number just comes up. Planes crash. People die. Should we drive instead? More people die driving than flying. Living life is an assumption of the risk of injury or death. Flying drones comes with all kinds of risks. Charging the batteries is the least of them. I had a P3P, with 500g of attached external batteries, (attached but unfortunately not connected on that test flight) free fall from 215 feet directly above me, when the internal battery shut off in flight, while displaying 85% remaining in DJI GO. Fortunately, it landed 10 feet away from me, rather than on top of my head, or I wouldn't be here to write about it. Stuff happens. We have to assume some level of risk to fly drones. I naively assumed I was safer on the ground flying vicariously, instead of inside a piloted aircraft that could crash with me in it. Not true!

If I charged every LiPo battery I own in the various drones, remotes, cameras, flashes, Segway Minis, Segway Scooters, various eBikes, supplemental lights, horns, GPS devices, iPads, and iPhones outside, I would need a full double car carport! I charge them all indoors for convenience and security, unattended, but remove them when they are charged. I accept the risk.

Do what you feel you need to, to feel safe, as will I, and let's both hope that is enough.

I don't know where you have wandered off to. Lets get back to the point. Post #5. The fact remains, @The RAPier gives good advice- charging LiPO's should not be left unattended where failure might prevent a significant fire hazard. Your response that risk of fire is not a valid concern with DJI batteries is demonstrably false. The fact you you weren't aware of a DJI battery catching fire during charging or that you might assume all such instances would be widely reported in the media are not good reasons for reaching a conclusion as to potential risks. DJI batteries use LiPO cells. The risks are well understood. Suggesting to people there is no risk false.

 

[Deleted member 93449]

Smart batteries are great but electronic devices do fail so I would always take precautions regardless of the built in safety circuitry in the batteries.

 

[GadgetGuy]

Suggesting to people there is no risk [is] false.

Never said that. Once again, you take my carefully worded statements and dumb them down to fit your narrative. Still waiting for any report of a recent, undamaged DJI battery catching fire, during charging, on a DJI charger, within the warranty period. Ball is in your court to prove me wrong, to establish that there are any such reports to find. Charging all your batteries outside is killing a gnat with a sledge hammer. Overkill. Unnecessary. Bad advice.

 

[WithTheBirds]

Never said that. Once again, you take my carefully worded statements and dumb them down to fit your narrative. Still waiting for any report of a recent, undamaged DJI battery catching fire, during charging, on a DJI charger, within the warranty period. Ball is in your court to prove me wrong, to establish that there are any such reports to find. Charging all your batteries outside is killing a gnat with a sledge hammer. Overkill. Unnecessary. Bad advice.

Searching for reports of incidents, particularly limited to the scope you propose would be a waste of effort.

The problem is with your presuppositions that LiION cells in DJI batteries are somehow free from the known chemical and performance characteristics of those used in other LiPO’s and that people don’t continue to charge packs over 6 months old. By the way- the 6 month in or out of warranty criteria is almost meaningless, failures can occur early in service life.

I don’t have a narrative. I challenged your suggestion there is no risk of LiION batteries are not at risk of catching fire while charging. That is demonstrably wrong. The risk might be small however people should have the option of making their own assessment as to whether they may wish to avoid it.

 

[DanMan32]

Let's just say the risk is on par with one's phone, tablet and laptop. Few would bother charging those outside or in ammo containers, even with a few models with chronic problems surfacing.

 

[GadgetGuy]

I don’t have a narrative. I challenged your suggestion there is no risk of LiION batteries are not at risk of catching fire while charging. That is demonstrably wrong. The risk might be small however people should have the option of making their own assessment as to whether they may wish to avoid it.

Once again, I never said there was no risk!
I stated "Current DJI batteries are not catching fire while being charged on DJI chargers."
Prove me wrong! Saying they could is not good enough to disprove the statement!

 

[GadgetGuy]

Let's just say the risk is on par with one's phone, tablet and laptop. Few would bother charging those outside or in ammo containers, even with a few models with chronic problems surfacing.

Amen!