Intelligent Battery Life

[ToddCarey]

I know these batteries are intended to assist us in getting better battery life, but my question is on the low end, is there damage to the battery when you pull it down to 10% or lower. I do not like to go below 25% for many reasons, but just curious if anyone knows how accurate to the battery's bottom end capabilities are the indicators we get from the app. I have read some guys say they cancelled an emergency low battery landing and made is several hundred meters further to get home. While my logic would be to make a safe landing before I pushed that envelope, my curiosity is what are the drop dead (if you were caught over water for example), and when going that low, does it damage the battery?

 

[kilomikebravo]

From what I've read here over the past couple of months, allowing the battery to get at or near zero will probably render the battery useless. LIPO's don't like the far ends of the charge spectrum. Much better to accept a little less flight time and bring the aircraft back so when it lands you have at least 20-30 percent. Being a nervous Nellie, I shoot for 30 or higher on landing depending upon the wind and distance.

 

[CanadaDrone]

I know these batteries are intended to assist us in getting better battery life, but my question is on the low end, is there damage to the battery when you pull it down to 10% or lower. I do not like to go below 25% for many reasons, but just curious if anyone knows how accurate to the battery's bottom end capabilities are the indicators we get from the app. I have read some guys say they cancelled an emergency low battery landing and made is several hundred meters further to get home. While my logic would be to make a safe landing before I pushed that envelope, my curiosity is what are the drop dead (if you were caught over water for example), and when going that low, does it damage the battery?

Lithium batteries of all types, including the ones in your drone, do not like :

- Being at a very low charge level, especially for any length of time - this can fully ruin them and is what most often does
- Being too hot (they will swell and possibly start a fire or damage themselves and the casing)
- Being too cold during use (hence DJI's temperature recommendations)
- Being at maximum charge for long periods of time (DJI does protect against this though, they self discharge to 65% or so after ~10 days but it's not a good habit)
- Sitting for long periods of time without a charge/discharge cycle (for DJI this is a maximum of 3 months)

I personally would never run my batteries down to 10% or lower for a number of reasons including cell longevity, possible voltage drop (drone will crash), and having a safety buffer for the unexpected (i.e. headwind while returning). Almost every single thread I have read about someone's drone falling out of the sky was either at a battery percentage of less than 20% (possible voltage drop), or flying in temperatures below DJI's recommendation. 25-30% return home is best practice not only from a safety perspective, but also for your battery health. You can still get well over 20 minutes of flight time which I think is still very generous. Stories like "I ran it down to 0% once and it was fine" are not reasons to try it yourself IMHO.

Running it to zero and then charging it isn't going to ruin it in one go, but it is really not good for it, not to mention incredibly risky for your drone and possibly your liability. Running it to zero and then leaving it there is about the worst thing you could do. Another reason to have a healthy battery is if sometime down the road you ever do have to run it to zero or near zero in an emergency or unexpected scenario, it is more likely to tolerate it without a failure.

 

[ToddCarey]

I fully agree with the comments. I have also run Lithium batteries in all types of RC equipment. My main point of the question is does anyone know how DJI has programmed these "intelligent" batteries. For example, when they report the battery at 10%, is that the real number, or just at 10% of where they want you to run it down to......

 

[CanadaDrone]

I fully agree with the comments. I have also run Lithium batteries in all types of RC equipment. My main point of the question is does anyone know how DJI has programmed these "intelligent" batteries. For example, when they report the battery at 10%, is that the real number, or just at 10% of where they want you to run it down to......

People have different theories on this but I have never seen it objectively demonstrated one way or the other. Given the amount of failures I have read about while on extremely low battery (coincidence or not we don't know for sure), I am inclined to believe it is real or close enough to real that it doesn't matter. If there is any leeway built in, it is very small. For example if DJI is showing 5% there is no way you still have 30%, so it's a moot point in my mind. RTH at 25-30% after a 20+ minute flight is already more than I thought I could ask for, so I'm happy.

 

[old man mavic]

I fully agree with the comments. I have also run Lithium batteries in all types of RC equipment. My main point of the question is does anyone know how DJI has programmed these "intelligent" batteries. For example, when they report the battery at 10%, is that the real number, or just at 10% of where they want you to run it down to......

i think you will find that the reading you get on the app when it is flying is not really that accurate and its the same with the lights on the battery they are an estimated charge level when the battery is in use i have turned mine off with one light flashing about 20 percent remaining only to have the light go steady once the battery has been turned off and stood for a few minutes as the cells recover and cool down the intelligent part of the batteries built in charging system should prevent it not only being overcharged but also prevent it from being over discharged

 

[old man mavic]

CanadaDrone hit the nail on the head with his reply lipos need regular care store them around 3.8 volts per cell and do not leave them for more than a month before a charge discharge cycle i have lipos more than two years old and they still give good flight times

 

[Hagibis]

My view and experiences from RC cars is that the actual cell voltage is the key, not the percentage value of the remaining charge in the batteries. Especially when the percentage value is the total value, not per cell. LiPo cell voltage should not be less than 3.2V, and definitely not less than 3.0V ever, otherwise it can die.

My M2P cell voltage is around 3.6V when the remote says 10% remaining, so there is plenty of juice left in the batteries. Again, my view is that DJI has set relatively high safety margin just to be sure that the precious drone will never run out of batteries and can be flown home as you can override the forced landing at 10%. DJI also wants to protect from over discharging.

Another topic about longevity of the batteries. In the RC car world the recommendation is not to keep batteries fully charged more than a day, but for unknown reason to me drone battery recommendation seems to be 3 days. I have purchased this little cable so that i can discharge the batteries using my battery charges instead of discharging them using the drone: New For DJI Mavic 2 Pro Battery To B6AC Balance Charger Charging Cable Adapter 809620060001 | eBay

 

[BlueRidge]

Hey All,

So what is the best storage procedure? You fly the battery down to 30%....and then what? Should I charge it back to 100% even though I may not fly for three weeks, or a month? I actually emailed DJI with this very question, and from what I understood, they said charge it, and the battery will take care of itself. Thanks for the advice.

 

[old man mavic]

Hey All,

So what is the best storage procedure? You fly the battery down to 30%....and then what? Should I charge it back to 100% even though I may not fly for three weeks, or a month? I actually emailed DJI with this very question, and from what I understood, they said charge it, and the battery will take care of itself. Thanks for the advice.

if you want to follow DJIs advice fine its your drone your money and your decision posters are just giving their advice based on their experience with lipos good flying

 

[CanadaDrone]

Hey All,

So what is the best storage procedure? You fly the battery down to 30%....and then what? Should I charge it back to 100% even though I may not fly for three weeks, or a month? I actually emailed DJI with this very question, and from what I understood, they said charge it, and the battery will take care of itself. Thanks for the advice.

The only time your batteries should be at 100% is if you're about to fly. If you are done flying and wont be flying for a week or whatever, charge them up to around 60-70% (3rd light blinking then pull it off the charger) and leave them (for up to 3 months maximum - then they should be cycled again).

If you charge the battery up to 100% and leave it, after 10 days or so the battery will automatically discharge itself to 65% (which is what DJI's reply was referencing), however that 10 days at 100% is not good for the battery even though it will tolerate it.

There is a significant difference between best practice, and what you can probably get away with in the short term. Where you decide to draw the line is entirely up to you, just make sure you are fully informed first.

 

[ZooCougar]

Good thread here.

What is the low end of advisable voltage?

I’ve only had my M2P for about a month, but I have gotten into the habit of watching the voltage really closely. In many of the videos and podcasts I have watched the experts say that once your voltage gets below a certain level you better be landing no matter what the charge level says.

 

[ZooCougar]

Also I have been playing with the kitty hawk app which shows me which batteries I have been using and how many cycles they have been in. I have to do a better job of spreading out use.

 

[ottodawg]

Good thread here.

What is the low end of advisable voltage?

I’ve only had my M2P for about a month, but I have gotten into the habit of watching the voltage really closely. In many of the videos and podcasts I have watched the experts say that once your voltage gets below a certain level you better be landing no matter what the charge level says.

Well at 10% it's going to try and auto land, so you'll have to hold the left stick up to continue to fly. I've flown to 0% which was 3.5v. Could have gone longer but I was were I needed to be. If you hit 3.0v you'll probably be tossing the battery.

 

[Wilmer Schock]

Is there any way to control the battery discharge? In the good old bad days, the radio control airplane guys for the Ni-cad batteries had chargers/dischargers since they had to be completely cycled to avoid the dreaded "memory". Is there any way to discharge the dji (specifically the Mavic 2P) batteries, other than flying, leaving them in the a/c on, or just letting them sit?

 

[old man mavic]

i have made a discharger that uses a 55watt auto car bulb the single type used in a fog or spot light they have a nice strong filament that can handle the extra voltage from the extra voltage from 4C batteries i use it to discharge standard 3C batts and my mave batts plus my Ph3 which are 4C the only issue is the bulb gets extremely hot when it is on and needs some sort of mount to hold it also it is advisable to have an on off switch to isolate the battery when plugging or unplugging the batt to avoid any chance of a short happening see the thread titled Mavic 2 battery discharger there is a picture of my discharger on there

 

[lalojamesliz]

I have some turnigy 3s batteries for my rc planes. they are about 3 years old and still work great. i only charge them to 100% before i use them and store them at 3.75v to 3.85v per cell. I usually run them down to 3.7 and sometimes to 3.6ish. I dont use them a lot but they do have a good amount of use on each one and they have very little puffing but that's common for turnigy lipos from what I've seen.
the mavic 2 batteries are 10x more expensive than my rc plane batteries so I understand why people worry so much about them. I run my batteries down to 15% before I shut it off on average and store them at 55-65% they should be fine for a good while.
The only thing I dont like is that these dji batteries won't count a charge cycle unless its charged to 100%. if the batteries counted the mah that's been put into it and when that amount reaches the rated capacity then it counts as a cycle I'd like that better but that's probably asking too much.
these are smart batteries, not genius batteries

 

[Bill Ludwig]

If you really want to monitor your batteries, use AirData. It's free, and gives your tons of battery data for every flight. www.airdata.com

 

[Neo]

Thanks for the tip. I just signed up for Airdata and they have tons of useful info. But I'm not really sure how to interpret some of it.

Like this info I found about one of my batteries. Should I be concerned?

I consider my self to take care of my batteries. I usually dont let them drop down below 30 percent and never below 20 percent. However I always top them up to 100 percent regardless if I'm going to fly the day after or maybe in 3 weeks.

Seeing the red highlights got me worried. Sometimes not knowing is better [emoji4]

 

[Bill Ludwig]

Yes, there’s a reason to be concerned. That’s the power of AirData. Keep a very close eye on that battery, and probably close fly it close-in and see if that was an anomaly or maybe the battery is actually ready to be retired. That same screen, you may have noticed, has a legend at the bottom that explains the color differences in the bars.