Lost Confidence on My Mavic 2 Pro

[Fly_Me_To_The_Moon]

Hope future Mavic Pros have a tiny internal battery, say 5%, only used at end of flight, or in the event main battery failure. Maybe water proof for unexpected rain (I live in FL).

Would require charging an extra item, however. Unless its designed to be inserted separately. Just my random idea to improve the device further.

 

[DanMan32]

I was thinking the same thing: aux power for being able to still deliver telemetry and respond to Find My Drone.

 

[Floater]

Battery life is a function of number of cycles, depth of cycle, operating temperature, storage temperature, and calendar time.

Spacecraft designers and operators that apply the lithium chemistries, especially those that operate in low orbits which cycle every 90 minutes or so, 24/7 severely limit the depth of cycle. Considering that a planned 4 year life involves over 23,000 cycles, they are understandably very conservative concerning battery operation. They would prefers to keep the charge state between 40% and 80% at all times and are extremely adverse to allowing the charge of these batteries to drop below 40%. This limitation has obvious limitations on battery performance, lowering the usable energy to mass to only 40% of the advertised energy to mass. There is active research on chemistries to decrease the cycle life sensitivity to depth of cycle. So maybe the space program will actually generate a useful spin-off for us!

So what does this mean for us? If we generally treat our batteries well (moderate storage charge, room temp storage and operation etc.) but fully charge and discharge for those record breaking flights, we can expect to see significant degradation by 50 cycles or so (say from full down to <10%). On the other hand if we are completely battery-****, only charging to 80% and landing by 40% for those 10 or 12 minute hops, the battery will be going strong after well over a hundred, perhaps many hundreds, assuming that there were no manufacturing defects.

 

[Maviculous]

Hope future Mavic Pros have a tiny internal battery, say 5%, only used at end of flight, or in the event main battery failure. Maybe water proof for unexpected rain (I live in FL).

Would require charging an extra item, however. Unless its designed to be inserted separately. Just my random idea to improve the device further.

Actually a brilliant frackin' idea! Really. Basic redundancy and safety. Wow...why is this NOT standard?

 

[WithTheBirds]

Actually a brilliant frackin' idea! Really. Basic redundancy and safety. Wow...why is this NOT standard?

For various reasons, including the fact that at 3 W/Hr capacity the reserve battery would not be able to maintain flight- at least not to the extent it might be any of the readily available LiPO chemistries.

 

[Flycaster]

To all who have responded so far, I have been in the R/C hobby for 26 years... I fly mostly giant R/C planes, have some racing drones and use a lot of lipo's on a daily basis. the batteries got charged properly all the time and kept an eye for sings of wear, failure etc. I wish that DJI put something on their app that if the battery starts to fail during flight, that it would warn you and return home to land if necessary.
my main grief is that we as consumers have to rely on the app to check the batteries unlike other lipos that I am able to check individual cell voltages. also that BS that the store would only check my batteries if I bought them there? This is a DJI store!! not a third party!.... most likely I will fly the mavic, but I feel that they are starting to behave like apple.. my original mavic was fine and had plenty of flights without any issues, one day it had sensor calibration issues, after many attempts to calibrate I ended having to send it in. the diagnosis was Gymbal limp? and felt it was a bogus diagnostic and they told me I could use my DJI care refresh, wich I used because I needed a drone asap. that replacement drone is the one that crashed in the water after the 7th flight. felt that the drone was not like my original, crisp and fast response. I babied my mavic and took good care of the equipment.. I feel that DJI no longer care of quality but mass production and profits.
And thank you all for the input!

There is, if you start getting deviations etc. you will get warnings.

 

[WithTheBirds]

Battery life is a function of number of cycles, depth of cycle, operating temperature, storage temperature, and calendar time.

Spacecraft designers and operators that apply the lithium chemistries, especially those that operate in low orbits which cycle every 90 minutes or so, 24/7 severely limit the depth of cycle. Considering that a planned 4 year life involves over 23,000 cycles, they are understandably very conservative concerning battery operation. They would prefers to keep the charge state between 40% and 80% at all times and are extremely adverse to allowing the charge of these batteries to drop below 40%. This limitation has obvious limitations on battery performance, lowering the usable energy to mass to only 40% of the advertised energy to mass. There is active research on chemistries to decrease the cycle life sensitivity to depth of cycle. So maybe the space program will actually generate a useful spin-off for us!

So what does this mean for us? If we generally treat our batteries well (moderate storage charge, room temp storage and operation etc.) but fully charge and discharge for those record breaking flights, we can expect to see significant degradation by 50 cycles or so (say from full down to <10%). On the other hand if we are completely battery-****, only charging to 80% and landing by 40% for those 10 or 12 minute hops, the battery will be going strong after well over a hundred, perhaps many hundreds, assuming that there were no manufacturing defects.

You missed two critical factors- storage voltage and discharge current in use. The first demonstrably accelerates ageing and reduces safety while the second limits usability, simply because the effect of any internal resistance increase is obviously more pronounced with increased current.

The importance of increased flight time to most operators provides that we take the compromise here. The suggested 40/80 rule is impractical. Most of us have had very good experience with DJI battery life, 200 cycles not being an uncommon number.

Your recommendations with respect to storage will see significant benefits if followed- the suggestion we might only see 50 cycles when flown down to 10% has no merit however and might cause unnecessary concern.

 

[Maviculous]

You missed two critical factors- storage voltage and discharge current in use. The first demonstrably accelerates ageing and reduces safety while the second limits usability, simply because the effect of any internal resistance increase is obviously more pronounced with increased current.

The importance of increased flight time to most operators provides that we take the compromise here. The suggested 40/80 rule is impractical. Most of us have had very good experience with DJI battery life, 200 cycles not being an uncommon number.

Your recommendations with respect to storage will see significant benefits if followed- the suggestion we might only see 50 cycles when flown down to 10% has no merit however and might cause unnecessary concern.

Oh! Of course...I actually was thinking along the lines of extra battery to broadcast location after failure/crash etc...

 

[WithTheBirds]

Oh! Of course...I actually was thinking along the lines of extra battery to broadcast location after failure/crash etc...

Hard to see a connection here- you answered the wrong post?

 

[DanMan32]

It should also be noted that 0% showing in the app is not 0% remaining usable capacity. DJI does incorporate a reserve which is considerable on the M2.

 

[Maviculous]

Hard to see a connection here- you answered the wrong post?

doh. thanks. it's a few posts prior.

 

[Maviculous]

For various reasons, including the fact that at 3 W/Hr capacity the reserve battery would not be able to maintain flight- at least not to the extent it might be any of the readily available LiPO chemistries.

Oh! Of course...I actually was thinking along the lines of extra battery to broadcast location after failure/crash etc...

 

[Kopriti]

Thank you all who replied to my post, I have to say that I sold My M2P and will wait for a better drone to come up. I am in no hurry to have another high $$ drone, in the mean time I will use my racing drone with my go pro. LOL

 

[Davros007]

After my recent water crash, I totally lost confidence on the mavic and the replacement has not been flown. a few months back, I was flying above water when suddenly the drone just fell out of the sky. at first DJI denied my claim and they wanted over $1500 to fix it. after several emails and them finally getting the flight logs etc, they admitted it was a hardware failure and they replaced the drone. they didn't give me a reason beside hardware failure. checked the logs and the only thing I found was a Battery deviation. I called my local DJI store and asked if they could check all my batteries, they told me that only if I bought them there they would perform a check. after this I am considering selling the mavic and move to another brand...Autel?
I'd like to hear what others think about this....

I would suspect the only reason there may be less ‘complaints’ about another brand is that there are far less of them. DJI has what, 75% of the market? So if they are are equally as good as other brands, you’d expect 75% of complaints to be about DJI drones! Just to keep in mind.