DJI Batteries and Cold Weather . . .

[Me262]

The sweet-spot for a LiPo storage wise is 3,7-3,8V/cell ... if you don't want to degrade your battery's prematurely they shouldn't be outside that storage voltage longer than 48h as a thumb rule, it's equal bad to keep them too full as too empty.

For a DJI battery the storage voltage translates to approx. 30-50% ...

Any way to have the voltage continously displayed in the DJI Fly App (Mini 2)

Or the only option for that is to go to about and check the battery voltage/temp there?

 

[slup]

Any way to have the voltage continously displayed in the DJI Fly App (Mini 2)

Or the only option for that is to go to about and check the battery voltage/temp there?

Don't know, flying with the DJI GO 4 app myself ... aim for 30-50% & you have them where they should be for storage.

 

[airbuspilot]

Not very applicable in July, but back in February I had a successful 20 minute flight with my MA2 at -23°F (-30°C). I started the flight with the drone's battery at 77°F and the battery never cooled below 75°F.

 

[airbuspilot]

Separately, this afternoon I flew my Mavic Air 2 with the goal of achieving the hottest battery temperature possible.

65.8°C (150°F).

No cautions or error messages. The battery is not swollen. I am impressed.

 

[eEridani]

TLDR - but anyone else notice the official spec for the Mavic Air 2S is only 0 degrees C?

Specs : DJI Air 2S​

• Operating Temperature Range: 0° to 40°C (32° to 104°F)​

Officially, if it is snowing, or freezing outside, or cold enough for these, you are violating the warranty by flying your drone.

I even asked DJI to ensure I was ready their spec correctly, and they said the same, that the gimble of the Air 2 S is sensitive to cold, and should not be flown at 0C or lower. It was this single spec that made me choose the Air 2 over the Air 2 S.

​

Specs : DJI Air 2​

• Operating Temperature Range: -10° to 40°C (14° to 104°F)​

 

[FlyingFranky]

Don't know, flying with the DJI GO 4 app myself ... aim for 30-50% & you have them where they should be for storage.

Hello, first time poster so excuse me if I am wrong. I was under the impression that the intelligent battery firmware slowly discharges the batteries depending on duration since last discharge, use, or whatever the parameters are. Is this a concern with the intelligent batteries? If the firmware does indeed help regulate charge on the batteries, the battery health gains by keeping it in this range with intelligent batteries seems pretty trivial.

 

[slup]

Hello, first time poster so excuse me if I am wrong. I was under the impression that the intelligent battery firmware slowly discharges the batteries depending on duration since last discharge, use, or whatever the parameters are. Is this a concern with the intelligent batteries? If the firmware does indeed help regulate charge on the batteries, the battery health gains by keeping it in this range with intelligent batteries seems pretty trivial.

Yep ... that's a big misconception about the "Smart" battery auto discharge ...

A LiPo battery shall not be outside storage voltage (3,7-3,8V/cell) for not much longer than 48h ... the auto discharge usually is programmed to discharge it during 10 days (on some DJI models you can set the time down but not for all).

So going only with the auto discharge will generate excessive wear on your batteries ... but it will save the battery long enough so the DJI battery warranty can expire (12 month at present).

 

[Spielben]

Some of you may know Ken Booth who was originally active with DJI and very involved in their Battery Design. :

(the below is 100% from Ken Booth)
"First please look at the attached image, this should really explain all you need to know on how cold effects capacity. Once you understand this, most of the other pieces come together.

Now that we understand what cold does to capacity let us talk about overall discharge.

Most of us know that C is based on overall capacity, so if your capacity goes down, so will your C rating. Unfortunately, DJI does not use batteries that have much overhead, this is mostly due to keep the weight down at a certain price point. So, when we start to pull from this cold battery a few things can happen. If the pack has not been preheated, it will start to preheat itself. You are probably asking; well if that’s the case, why do I have to worry about preheating?

Well, if the battery is too cold and C rating has been affected, it will not be able to supply enough output (required C), going over its current C rating due to loss of capacity. This starts heating the pack up rapidly. Which in turn makes the pack quickly go past normal operating temperatures, which will also decrease output. This will cause immediate damage and more than likely a cell failure under extreme conditions. This is called thermal runaway.

The next thing that can happen is part of the smart logic and safety features of these packs. Since the cold does affect overall capacity, this could kick the overcharge protection in and start a self-discharge of the pack(s). In theory this is good and prevents possible damage or even a fire but can also play with the SOC (state of charge) that calculates the current charge state. While the logic is pretty darn good its not perfect. The percentage could be off as much as 20-30%. The same goes for an automatic timed self-discharge, you NEVER want to fly a pack that has been allowed to self-discharge. I would also highly advise to never fly ANY partially discharged pack unless that pack has been used that same day.

So, what can we do to help or minimize these issues?

Preheat packs in cooler weather. I would say anything below 55F you should start paying attention. One easy way to keep packs nice and warm in colder weather is dry rice and an ice chest / bag. Take a few pounds of dry rice (this depends on how big of a cooler you have) and place the rice in a large zip-lock bag(s). Microwave the rice for about 5-10mins or until very hot. Place the rice in the cooler. This should keep packs warm for most of the day. I prefer this method since the rice is reusable and does help with small amounts of moisture as well.

DO NOT Keep full pack charged for more than 24, 48 hours MAX! Any type of lipo does not like to be kept fully charge for a long period. This is not just for smart packs, any lipo will degrade over time if kept in a full charge state. Signs of this can be shorter flight times and possibly puffing (gassing) in extreme cases.

DO NOT over discharge your packs. Anything past 20%, consider it a reserve. If you commonly go past this 20% mark you will shorten you packs life. This is extremely important during extreme temps, both hot and cold weather.

DO NOT expect the same performance. In cold weather, even after preheating. Some craft keep packs warmer than others. Be easy on the packs, especially at the start of the flight, even after preheating.

Stop and hover. This is important for ANY time of year and should be included in you SOP. When you first take off, stop and hover for at least a minute. Even prior to a mapping run, take off and hover for a minute before the start of a mission. It is worth that 1 or 2mins less of mission time. Check all controls and watch the behavior of the craft. If you start to see drifting or any odd behavior, that is your clue to land and diagnose the issues. You would be surprised at how many logs of failures I have seen and the first thing the operator does is a punch out. This is probably the worst thing you can do with these types of craft. When these craft are not well, they usually show signs at the begging of flight. I simple hover with some minor control inputs can do wonders at showing a healthy or sick craft. This also allows the internals of the craft and packs to start warming up properly.

Check voltages and balances in the app and not percentages. Always have voltage options turned on. This is something to check when you are doing the hover and control test at the start of flight. Open the battery menu and check each cell, make sure everything looks good. Make sure you do not see any cells dropping rapidly and or voltage issues.

Voltages. A freshly charged pack should be around 4.2-4.3v per cell. A clue to a bad SOC is a percentage showing 99-100% but a much lower voltage. Once again, during that initial hover period check the cell voltages or overall voltage. If you see something like 3.9v at 99-100% charge, that pack either has a SOC issue or the pack is not healthy. If you do see any anomalies, do not risk it! Land and swap the packs.

Maintenance. With smart packs there’s only a few basic maintenance items you must be aware of. For older packs such as the p4 pack I would still recommend bringing these packs down below 10% every 20-30 flight or after long periods of storage. When you go past 20% make sure you are not flying hard and only hovering at a low altitude. The key here is to drain the pack as slow and gently as possible. What this does is perform something like a soft reset (calibration) on the SOC counter. Now if you are constantly using packs and not abusing them, you more than likely do not have to worry about a calibration. But remember long period of storage might require this to get the battery back to calculating accurately. After long storage periods its always best practice to monitor the pack during the initial flight. I know I am **** but if a pack has sat more than 3 months, I fully charge and then hover for the entire flight down to 20%. During this flight I am constantly monitoring the packs performance via the battery window. If the pack is not well this will usually show signs, especially voltages and balance issues.

Newer packs such as the m2 and enterprise models should not require this and most issues we see are due to storage charge and temperatures. With that being said, there are times a good battery calibration can bring back unhealthy packs in these new generation smart batteries.

I know I have probably missed some stuff, but it is simple. Keep packs above 60F in cold weather, not push them hard, do not keep batteries fully charged for long periods of time and do not store while fully charged in cold conditions.

I know for first responders, a lot of this is hard to do but you must develop a battery maintenance schedule. Batteries still need to be cycled. I would suggest at least twice a week down to 50% if kept at full levels.

One more thing, please know that warm weather works in a very similar way. You do not want packs starting off too warm. Try to keep packs below 90F prior to flight. Also, the same with storage, never store fully charged packs in extreme temperatures.

I have tried my best to not get too technical and put it laymen terms as best as I could."
(all credit goes to Ken Booth)

View attachment 123882

Some of you may know Ken Booth who was originally active with DJI and very involved in their Battery Design. :

(the below is 100% from Ken Booth)
"First please look at the attached image, this should really explain all you need to know on how cold effects capacity. Once you understand this, most of the other pieces come together.

Now that we understand what cold does to capacity let us talk about overall discharge.

Most of us know that C is based on overall capacity, so if your capacity goes down, so will your C rating. Unfortunately, DJI does not use batteries that have much overhead, this is mostly due to keep the weight down at a certain price point. So, when we start to pull from this cold battery a few things can happen. If the pack has not been preheated, it will start to preheat itself. You are probably asking; well if that’s the case, why do I have to worry about preheating?

Well, if the battery is too cold and C rating has been affected, it will not be able to supply enough output (required C), going over its current C rating due to loss of capacity. This starts heating the pack up rapidly. Which in turn makes the pack quickly go past normal operating temperatures, which will also decrease output. This will cause immediate damage and more than likely a cell failure under extreme conditions. This is called thermal runaway.

The next thing that can happen is part of the smart logic and safety features of these packs. Since the cold does affect overall capacity, this could kick the overcharge protection in and start a self-discharge of the pack(s). In theory this is good and prevents possible damage or even a fire but can also play with the SOC (state of charge) that calculates the current charge state. While the logic is pretty darn good its not perfect. The percentage could be off as much as 20-30%. The same goes for an automatic timed self-discharge, you NEVER want to fly a pack that has been allowed to self-discharge. I would also highly advise to never fly ANY partially discharged pack unless that pack has been used that same day.

So, what can we do to help or minimize these issues?

Preheat packs in cooler weather. I would say anything below 55F you should start paying attention. One easy way to keep packs nice and warm in colder weather is dry rice and an ice chest / bag. Take a few pounds of dry rice (this depends on how big of a cooler you have) and place the rice in a large zip-lock bag(s). Microwave the rice for about 5-10mins or until very hot. Place the rice in the cooler. This should keep packs warm for most of the day. I prefer this method since the rice is reusable and does help with small amounts of moisture as well.

DO NOT Keep full pack charged for more than 24, 48 hours MAX! Any type of lipo does not like to be kept fully charge for a long period. This is not just for smart packs, any lipo will degrade over time if kept in a full charge state. Signs of this can be shorter flight times and possibly puffing (gassing) in extreme cases.

DO NOT over discharge your packs. Anything past 20%, consider it a reserve. If you commonly go past this 20% mark you will shorten you packs life. This is extremely important during extreme temps, both hot and cold weather.

DO NOT expect the same performance. In cold weather, even after preheating. Some craft keep packs warmer than others. Be easy on the packs, especially at the start of the flight, even after preheating.

Stop and hover. This is important for ANY time of year and should be included in you SOP. When you first take off, stop and hover for at least a minute. Even prior to a mapping run, take off and hover for a minute before the start of a mission. It is worth that 1 or 2mins less of mission time. Check all controls and watch the behavior of the craft. If you start to see drifting or any odd behavior, that is your clue to land and diagnose the issues. You would be surprised at how many logs of failures I have seen and the first thing the operator does is a punch out. This is probably the worst thing you can do with these types of craft. When these craft are not well, they usually show signs at the begging of flight. I simple hover with some minor control inputs can do wonders at showing a healthy or sick craft. This also allows the internals of the craft and packs to start warming up properly.

Check voltages and balances in the app and not percentages. Always have voltage options turned on. This is something to check when you are doing the hover and control test at the start of flight. Open the battery menu and check each cell, make sure everything looks good. Make sure you do not see any cells dropping rapidly and or voltage issues.

Voltages. A freshly charged pack should be around 4.2-4.3v per cell. A clue to a bad SOC is a percentage showing 99-100% but a much lower voltage. Once again, during that initial hover period check the cell voltages or overall voltage. If you see something like 3.9v at 99-100% charge, that pack either has a SOC issue or the pack is not healthy. If you do see any anomalies, do not risk it! Land and swap the packs.

Maintenance. With smart packs there’s only a few basic maintenance items you must be aware of. For older packs such as the p4 pack I would still recommend bringing these packs down below 10% every 20-30 flight or after long periods of storage. When you go past 20% make sure you are not flying hard and only hovering at a low altitude. The key here is to drain the pack as slow and gently as possible. What this does is perform something like a soft reset (calibration) on the SOC counter. Now if you are constantly using packs and not abusing them, you more than likely do not have to worry about a calibration. But remember long period of storage might require this to get the battery back to calculating accurately. After long storage periods its always best practice to monitor the pack during the initial flight. I know I am **** but if a pack has sat more than 3 months, I fully charge and then hover for the entire flight down to 20%. During this flight I am constantly monitoring the packs performance via the battery window. If the pack is not well this will usually show signs, especially voltages and balance issues.

Newer packs such as the m2 and enterprise models should not require this and most issues we see are due to storage charge and temperatures. With that being said, there are times a good battery calibration can bring back unhealthy packs in these new generation smart batteries.

I know I have probably missed some stuff, but it is simple. Keep packs above 60F in cold weather, not push them hard, do not keep batteries fully charged for long periods of time and do not store while fully charged in cold conditions.

I know for first responders, a lot of this is hard to do but you must develop a battery maintenance schedule. Batteries still need to be cycled. I would suggest at least twice a week down to 50% if kept at full levels.

One more thing, please know that warm weather works in a very similar way. You do not want packs starting off too warm. Try to keep packs below 90F prior to flight. Also, the same with storage, never store fully charged packs in extreme temperatures.

I have tried my best to not get too technical and put it laymen terms as best as I could."
(all credit goes to Ken Booth)

View attachment 123882

Thank you so much for this precious datas.
Handling batteries needs care and knowledge.
Before flying FPV I had no ideas that a battery needs to be taking care of if you want the best out of it.
cheers

 

[Rodders]

Well who is right or who is wrong ????

 

[CanadaDrone]

Well who is right or who is wrong ????

The information in the original post is correct. All he did was re-hash basic LiPo care that broadly applies to all LiPo batteries, but it is correct, and for some people it helps to hear it from a more credible source such as someone who did work for DJI.

tl;dr ( this applies to most modern lithium batteries):

- Do not leave them fully charged for any longer than you have to (i.e. driving to your flying location). The auto-discharge function is more of a failsafe than a feature to be relied upon.
- Do not regularly discharge them below 20% or so, especially while flying or using them
- Do not let them sit with a very low charge for a long time (this is one of the worst things you can do)
- After use, let them cool off and then charge them up to a storage charge if they are not going to be used again immediately (around 3.8V per cell)
- Take extra care if using them in exceptionally hot or cold environments, and warm the batteries prior to use if you absolutely must fly in cold weather. End your flight earlier than usual in these conditions and do your best not to stress the drone while flying in these conditions.
- Do not store the batteries anywhere near a heat source, and preferably in a fireproof bag/safe. Storing them on the drone is a bad idea because on the off chance a battery fails catastrophically, you also lose your drone.

These are just best practices, and as always people will have anecdotal experience that may contradict one of the above points in a specific scenario, but if you follow the above you at least know you are doing all you reasonably can to avoid any issues.

You can apply most of the same principles to your other devices such as smartphones, and you will find their batteries last much longer than when abused.

 

[offtheback]

Elon Musk-Save us from this torture.Formulate a battery that needs no care!It will make you rich(er)

 

[TTP]

Today I flew two batteries in minus 15 C / plus 5 F.

No problem for the drone, I made sure that both batteries had a starting temp closer to plus 25 S / plus 77 F.

I was really winter-dressed, gloves fitted and a small heating coil in the right glove, as I almost always have that thumb on the right joystick and it gets cold.

Wonderful winter weather with radiant sun, unfortunately we only have a small thin film of snow.

 

[airbuspilot]

Today I flew two batteries in minus 15 C / plus 5 F.

No problem for the drone, I made sure that both batteries had a starting temp closer to plus 25 S / plus 77 F.

I was really winter-dressed, gloves fitted and a small heating coil in the right glove, as I almost always have that thumb on the right joystick and it gets cold.

Wonderful winter weather with radiant sun, unfortunately we only have a small thin film of snow.

Which model drone?

 

[slup]

Today I flew two batteries in minus 15 C / plus 5 F.

No problem for the drone, I made sure that both batteries had a starting temp closer to plus 25 S / plus 77 F.

I was really winter-dressed, gloves fitted and a small heating coil in the right glove, as I almost always have that thumb on the right joystick and it gets cold.

Wonderful winter weather with radiant sun, unfortunately we only have a small thin film of snow.

Just be aware about some battery related thing's when it comes to using them in very cold (or hot) ambient.

LiPo & LiIon batteries wears a lot when used in cold ambient temps ... they don't reach their proper working temp & by that will be very prone for voltage drops due to an increased internal resistance. Furthermore high amp draw in these conditions will slightly increase the permanent internal resistance due to electrolyte break down, put extra wear on them (this is worse in hot ambient temps though).

So if the battery is not freshly new & perhaps not cared for in detail ... using them in really cold ambient temps can make cells fail & drop down below 3v ... & there DJI crafts will force land then & there.

So just say that I flew in way colder temps than what's stipulated in the manual once & it went fine ... doesn't mean you haven't increased the wear & will not suffer the consequences of cell failures in future flights. As long as you doesn't follow up the trends regarding cell deviation, voltage drops, internal resistance & total capacity you mainly don't know if you was close to disaster or not.

 

[old man mavic]

here in the UK with our ever changing weather patterns ,even sometimes on a daily basis it is very difficult to have a controlled regimen, for keeping our drone batteries at good storage voltage levels, due to the unpredictability of knowing for sure when you are going to be able to fly again
so my way of coping with this is to make sure i do not drop my end of flight charge below 40%
yes it shortens the flight time ,but that can be overcome by having extra batteries
my sweet spot is 4 batteries per drone all numbered and used in sequence, have been flying my MPP since November 2018 and all 4 of my batteries have no swelling and still show 100% charge in the App before take off and even on airdata which tends to be more picky with such measurements show them at 97% when i look at battery care
i have found that this method saves me from having to be constantly putting in small top up charges ,after a days flying because the voltage has dropped below the recommended per cell reading ,but no matter how careful we are with our battery care ,its inevitable that there will come a day when they no longer function as they should ,so all we can do is try to put that day off for as long as possible

 

[Ralph thompson]

Probably not a common problem but my M2ED is just going back to DJI under the Care program because I cracked the body in very cold conditions. I had difficulty getting the battery out with gloves on & probably squeezed the body too hard. There now a small crack on the side. Never had this problem with the M2P but the battery fit seems much tighter on the M2ED

 

[TTP]

Which model drone?

Sorry, M2P.

 

[Ralph thompson]

The crack occurred in the M2ED, 6mths old. I've had the M2P for 2 years (plus I1P since 2015) and done lots of cold weather flying around Montreal and not had this problem. My fault, I should have been more care, but it was very cold, -10C with quite a strong breeze with wind chill factor.

 

[TTP]

Today's flight was a conscious test of the cold flight weather.

Deliberately chose my two best batteries No. 9, 74 charges and No. 10, 86 charges.

Both of these batteries, have a battery warning of 28% and never discharged below 24% when I fly.

In summary, both the drone and I handled the cold well, the weak point is as we all know, the battery in the drone, I fly with SC so it is a minor problem.

 

[slup]

... the weak point is as we all know, the battery in the drone, I fly with SC so it is a minor problem.

How come ... I mean, how can flying with a SC mitigate possible problems with the drone battery?