Hi,
This morning I've had a serious problem with tow of my battery. I was around 60% autonomy and the battery soudenly shut down to 1%. The inspire landed. Hopefully it landed on the grass.
I've made all the check. The battery were ok. I can't understand what's the problem. Now I'm afaid about flying this machine.
Do you have an idea about my issue ?

regards

PaulKerry Posted at 2015-10-21 06:59
It sounds like it had been left charged long enough for it to go into an auto-discharge cycle which  ...

I agree this does sound like the battery was auto discharged.

Please never fly with a partially charged pack.

Thank you Paul for your advice. I will charge my battery this evening and test it tomorrow.

Did you take flight at 60% or 100%. I've learned to take flight at 100% or take on the problem of battery depletion within seconds at times. I've never flown with a partial charge since.

Paul I agree with you. It is dangerous how the batteries discharge and most don't realize that flying from start at 60% can be fatal. I've learned as mentioned in previous post to charge and fly at 100% each and ever time.

I've tested the battery this morning after full charging it. It works perfect.
Yesterday I took flight at 60% after 10 days without flying. It was a mistake I will never do it again.
Thanks guys

Paul

When the batteries auto discharge they do show the voltage drop via the lights. They should not still show 100% charged if left alone to do a complete storage discharge. Remember first light doesn't mean 100%, it could be anywhere between 87.5% - 100%. To top off your batteries before flight if they have sat for a few days, you should first power them ON. Then connect to charger, they will then charge to 100%.

This is why I suggest to keep auto discharge to 1-2 days. You don't want a full pack to sit longer than that anyways imho. (just a reminder each time you hit the power button to check voltages, it will reset the auto discharge timer).

If you fully understood these batteries you would have a different opinion regarding them!

This issue occurs when the battery is allowed to self discharge and isn't charged before being flown. Default time before it starts this process is 2 days, I set mine to 10 days to limit the likelihood of this problem occurring.

I have found that now for whatever reason you need to turn the battery on if it has all the lights turned on to charge it that is the only way to charge it to 100% when it is above three lights. I had this problem until I started turning the batteries on that I thought were full when I put them on the charger I have had no further problems since adopting that ritual

Turning the battery on does not reset the self discharge timer in my experience.  That is why people have issues on partial batteries and misunderstand the issue so often considering that the default time is two days. If you charge it the day before you use it down to like 60% and then the next day use it again and have the issue occur because its past the timer and using it doesn't seem to reset it.

You really shouldn't be able to shorten their life or damage them. They shut themselves off before they get to a low enough voltage to cause any damage to them, supposedly anyway,

PaulKerry Posted at 2015-10-22 18:19
That's not what I meant.

If I am deliberately ensuring that my batteries remain fully charged, I  ...

oh i see.  You wont be able to keep them fully charged unless you keep watching the level and charging them consistently, the self discharge feature will drain them down to 60%, the process takes 2 days to go from 100% to 60% if you dont interfere.

Hitting the button will restart the auto discharge .. It's not hard to understand. If you don't touch the batteries they will auto discharge.

Paul, I have been flying with these batteries for a very long time. I fully understand them and it seems you just want to argue on points that really don't matter. You use a tool how it was design to be used.

So lets recap:
If you hit the battery button this will reset the self discharge timer..
If you have a battery that needs to be topped off before flight, power on battery before connecting to charger.

It's really that simple.

808 Aerial Imag Posted at 2015-10-23 01:50
I have found that now for whatever reason you need to turn the battery on if it has all the lights t ...

Bob, you are making very valid point and I hope that others will take proper note of that.  
Addition of Battery Charging Hub is also a very effortless way to manage the batteries; it is very good product for ½ of the battery price and it will look after four of your batteries.  
The only fault with the DJI battery design team is that they trying to do too much and by look of it they are young bright “boys” with not enough real life experience.
Just give them a bit more time AND do not even think about taking off with partially charged batteries.

DJI-BladeStrike Posted at 2015-10-24 23:36
Hitting the button will restart the auto discharge .. It's not hard to understand. If you don't touc ...

In what firmware version did they implement that pressing the battery button to check it would reset the self discharge timer?

PaulKerry Posted at 2015-10-25 06:32
That battery that I've been checking around twice a day...

It seems that it's auto-discharged. It ...

Yea exactly, I was pretty sure pressing the button on mine didn't restart the timer either but I'm on older firmware so I was wondering if they changed it in newer versions.  Dji doesn't seem to be very good at making bug free firmware/apps that work as intended though, maybe they coded in that feature but it just doesn't work, lol

Hello all!

I'm new to DJI Inspire, but I have 40 years in RC modeling and 15 years of experience of LiPo batteries.
I have been a competition pilot and i do not like unsafe battery behaviorism. In competition RC planes we dual batteries (for RC).


LiPo voltage VS. Capacity
What I wanted to get at is that in RC we ALWAYS use voltage to determine remaining capacity. The voltage is, as most likely already know, proportional to remaining capacity between 3,6V (empty) and 4,2V (full) per cell.
This means that volt/capacity can be measured as: (per cell)
4,2V = 100%
4,03V = 76%
3,86V = 52%
3,83V = 42%
3,79V = 30%
3,7V  = 11%
3,6V  = 0%
approx 3,8V = storage
This measurement works in 99,99% of cases. Only known cases I know where method fails is if a cell suddenly breaks.

DJI Inspire battery management
Then I see that Inspires battery management seems to use a combination of voltage and the amount of energy (mAh) that have been charged into the battery (last charge).
Can anybode explain in detail how DJI manages batteries?
So, my next question is if anyone has checked all cells voltage and "estimated" remaining capacity when problems occurs?
It would be very interesting to see this if possible both before and after capacity drop.

For DJI future development I would like to see a small extra battery option (1 min flight) for safety when flying where only GTH landing is safe. Btw, I also had this problem once. I flew a automated mission with Litchi Android app and suddenly it just landed:-( Very scary. Fortunately it was a demo to a friend at the RC field. But over water I would be lost.

//Ulf

Yes, you are right Paul. Voltages shown are battery in rest.
Values under load I don't know. But, based on what I wrote it is possible to measure battery capacity before inserted.
If the battery is showing 24.18V then you have 76% remaining for example. After insert of battery you can check capacity and compare with telemetry.

I will try to find out how DJI calculates remaining capacity.

Hello Paul!

The chart I posted was a typical example. Each LiPo manufactor has this data specific to their battery. I'm no expert on the chemicals of LiPo, I only know the practical use.
I found the attached example. In a more advanced system the correct curve could be used to calculate remaining capacity accurate at all loads.

But still I don't know if the issue with DJI batteries dropping fast is caused by:
a) System shows 60% at start but remaining capacity is actually much lower?
b) System shows 60% at start and then in flight capacity calculation goes wrong and system thinks battery is empty?

The reason I'm suggesting (b) is that I'm pretty sure my battery was not empty when it happened to me. On the other hand, I'm not sure of exactly how discharge works.

//Ulf

Lol oke guys I'm really lost now.
Just my experience.
Had a new TB47 with 4 cycles, fully charged it to 100 % 15 min before flight.
Had a short flight just was, battery was 40% full. After 1 hours mad a short new flight.
Battery level dropped from 37% to 6%, distance was 600 meters away from me.
Was very lucky to got my bird back in one piece, landed in front of me at n/a% lol. Just had my inspire for 3 days.
Checked the battery, battery life was 98% after 5 cycles.
Flew afterwards a several times and had no issues, but didn't trust it.
Contacted the local dealer and send the battery back, they promised to send me a new one, but I'm still waiting.

Can't someone engineer a loader/ unloader for people who don't want to be bordered with al these load and unload cycle times.
Just put all you battery's in the box and the box will do all the thinking. Just puss the button 1 hour before flight and the battery is fully charged.

Greeting

Betweenus Posted at 2015-10-29 05:46
Lol oke guys I'm really lost now.
Just my experience.
Had a new TB47 with 4 cycles, fully charged it ...

When that sudden drop issue happens to a battery it will happen every time even if you fully charge it untill you do the drain till self power off reset procedure.

PaulKerry Posted at 2015-10-28 16:32
How about a box, into which you drop 4 batteries, press a couple of buttons for each battery and c ...

I love mine Paul and preordered on the first batch.  You really don't know what you are missing until you have one of these...

Rich

I know what you're missing if you do have one, about $500, lol

Recently I completed a flight with according to "Go" 12 minutes flying.

After just 1 minute the aircraft fell out the sky.

The battery when the aircraft was recovered had "blown" considerably. The video on the app and on Shou ceased with the aircraft at 30 odd metres above ground.

This battery had previously on the flight charge cycle, been slow to charge and I wonder if this was a sign it was failing then. This aircraft had flown 6 hours total on 2 batteries. I stop flying normally at 30% and we recharge.

Anyone else ?

We fly professionally so am concerned now and will have all other slow charge batteries checked professionally in future.

chris@tnld.com. Posted at 2015-10-29 13:34
Recently I completed a flight with according to "Go" 12 minutes flying.

After just 1 minute the air ...

How many charge cycles has it gone through? Have you done the drain it till it shuts itself off reset procedure every 10 charge cycles like the owners states under battery maintenance? Do you let them cool off after a flight before you recharge them?

PaulKerry Posted at 2015-10-29 00:32
How about a box, into which you drop 4 batteries, press a couple of buttons for each battery and c ...

Hi Paul,
Thanks you for sending us your pics. Every dji pilots wet dream, I think.
Just curious if you are sponsored by DJI? Lol

sultangris01@gm Posted at 2015-10-28 23:55
When that sudden drop issue happens to a battery it will happen every time even if you fully charg ...

Oke,
And how do I do this..
Sorry I didn't rfm

Betweenus Posted at 2015-10-30 01:23
Oke,
And how do I do this..
Sorry I didn't rfm

Start with a fully charged battery and Fly till it forces you to land and then let it sit there till it shuts off by itself. Wire about an hour for the battery to cool and recharge it and should be good.

Oh and if it's doing the sudden drop problem fly close to the ground in case it loses power and crashes. Hovering about a for of the ground is good.

sultangris01@gm Posted at 2015-10-29 22:27
How many charge cycles has it gone through? Have you done the drain it till it shuts itself off re ...

Yes we cool the batteries down at least 1 hour before charging.
Recycles, well as stated the aircraft has only flown low hours on 2 batteries, we always charge as a pair, so no more than 5 charges per battery therefore drain not required before failure.

chris@tnld.com. Posted at 2015-10-30 04:59
Yes we cool the batteries down at least 1 hour before charging.
Recycles, well as stated the aircr ...

I'm guessing it probably started its self discharge mode before you flew it. Recommend you fully drain it by hovering a foot off the ground till it forces landing, then let it sit there till it powers itself off. Then fully recharge it and fly it carefully close to the ground in case it happens again. Shouldn't happen again though. That process above should fix it if the self discharge bug was the cause.

PaulKerry Posted at 2015-10-29 23:12
Or, in the UK, around £450 !!!!

Paul..

Hi Paul,

Just checked the prices in Germany and the Netherlands. All 529 euro pffff.
But my birthday is coming up in February.

Or should I start a fundraising?? Lol

aerobat Posted at 2015-10-27 02:27
Hello all!

I'm new to DJI Inspire, but I have 40 years in RC modeling and 15 years of experience of LiPo batteries.
[Image]

Hello
I had this happen to me on Christmas day 12/25/22


The mp2 was sitting outside in 10 degrees F while I set up for 10 minutes, I discovered I needed to update and returned the drone to 70 degree, update completed return the drone back outside. Take off all systems normal, battery at 95% , flying I noticed the battery down to 88% and dropping, within 60 seconds the battery was at 0% I was shocked! The drone landed itself in a very difficult place to retrieve, on the side of a mountain,

I initially started a fly away report but good weather and the proper hiking equipment I was able to find my perfectly intact drone.

I got lucky and the battery was empty. , Recharge to fill no problems