Please select Into the mobile phone version | Continue to access the computer ver.
Battery Percentage vs Voltage. (Pack Condition/Health)
12Next >
4288 40 2016-2-5
Uploading and Loding Picture ...(0/1)
o(^-^)o
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

Many times I have seen posts whereby a pilot has started with a partially used stored battery, subsequently had problems with their Phantom very quickly going Critical low battery and either forcing a landing/RTH or a crash.
  
For a few weeks I have been trying to understand why a seemingly Healthy Battery Pack with around 70% or 80% capacity would within minutes go Critically Low.

To experiment I purposely discharged my fully charged batteries  to around 70%, left them for around 3-5 days, and then put them in my P3 and hovered around 1.5m off the ground and kept an eye on battery status.
(note: self-discharge is set to 10 days and I have not stored more then 3-5 days - so it’s out of the equation) also I have tried to be consistent with temperature, and always done the test when external/air temp is around 20C.
  
Today I believe I recreated the issue!!
  
The temperature was around 22C when I did the test and weather was sunny, no wind.
  
I took a partially charged battery that had been stored for 5 days and put it in the P3, after switching on (unarmed) it showed 66% charged battery, voltage per cell was 3.98V on all cells except for cell#1 that was 3.99 (negligible difference)
  
I brought up the Battery monitoring screen (to keep an eye on the battery) and to my surprise less than a minute gentle hovering (no drastic moves) into the flight the Voltage very quickly Dropped lower than it should be to around 3.58V and Yellow lined! - Note Battery is at 61% Capacity and only 1:13 minutes into the flight drops significantly Voltage Low in a very short time and stayed yellow. - See Screen Capture/Pic.

It also shows that I have around 12 minutes of flight time left - But with Voltage this Low I not sure that i could make anything close to this.
  
It’s my understanding the battery Percentage capacity is calculated, by the smart circuitry in the Pack, from how much mAH has gone into the battery at charge, and how much has been used when its being discharged.  - IT HAS NO RELATION TO THE VOLTAGE OF THE PACK
  
Therefor a discrepancy may exist, whereby the voltage of a pack may drop dangerously low, whilst the Percentage indicator still shows sufficient capacity.
  
I believe this has been the issue that many Pilots who have crashed on partially charged packs have suffered from.
  
So the lesson learnt is:
  
  • Charge packs fully before flying.. - Try not to use partially charged packs, especially if they have been left for a few days.
  • If you do use a partially charged pack, then hover for around a minute, and keep a Hawks Eye on each battery Voltage. - if any battery quickly drops to under 3.60v in around 1.5 minutes or less then stop flying and change the battery.
  • Do not use the Percentage as the only indicator to determine the state of the battery. - Turn On "Show the voltage on the main screen" and keep an eye on it. - if it goes yellow and stays yellow, then start to prepare to come back home or land somewhere safe.

If somebody can comment or has an explanation please let us know as i'm always keen to learn.

(and before anybody looks at the pic and starts to Holler that im hovering in a built up area - I have explicit permission from All my neighbours to fly in MY yard and I never fly/hover higher then 5 meters when im there. besides two of my neighbours fly drones as well. )


   
Batt_02.jpg
2016-2-5
Use props
quikdom
lvl.3
United Kingdom
Offline

I see percentage as a calculation and voltage as a statement of fact.  I may well be wrong?   
2016-2-6
Use props
WetDog
lvl.3
Flight distance : 1131886 ft
United States
Offline

I'm pretty sure you are correct.  You don't care what your 'percentage' is.  You care that the ESCs will start having hissyfits at a particular voltage and when you are close to that voltage and push the stick hard (or have to counter a wind or whatever) the voltage goes below a critical value and the drone crashes to the ground to avoid damaging the battery.....

I ALWAYS have the voltage displayed and typically look at the aircraft battery screen a couple of times per flight.

You also have 31 cycles on that battery - have you deep discharged it?
2016-2-6
Use props
[RCG]Balthazar
Second Officer
Flight distance : 475371 ft
Norway
Offline

Battery Percentage vs Voltage vs Temp

Flying on partially charged batteries have NEVER EVER been a problem before.
Following the battery % was NEVER EVER a problem in the P1's and P2's I've ovned.
Same goes for cold weather: NEVER EVER a problem before.
By now a few people in here has probably notices that I'm not exaggerating when I claim to have THOUSANDS of Phantom flights under my belt.
Neither would it be an understatement claiming to be a BIG fan of the Phantom Series.
Those who doubt my experience feel free to do so or have a look at my
Phantom Blog , My Parrot Blog or spy on my Facebook Profile (Pictures, comments and group memberships etc)

DO NOT TRUST THE % UNDER ANY CIRCUMSTANCE WHEN FLYING A P3!
I did and lost mt P3P November 22 and are currently in a process of ignorification by DJI Customer Service Germany.

The battery problems seems to have more or less vapourized after firmware 1.6 though, at least there's a lot less reports about battery issues after that.
It addresses balance charging, sets a limit to battery takeoff temp and also limits max throttle depending on the battery temp.

Have you updated your RC, Drone and Battery Firmwares?
2016-2-6
Use props
RodB
lvl.3

Australia
Offline


How are charging cycles calculated , is a cycle from very low  to full charge or are top ups from say 80% to full counted as a cycle .
2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

quikdom Posted at 2016-2-6 20:42
I see percentage as a calculation and voltage as a statement of fact.  I may well be wrong?

Not sure about that statement, if its wrong or right.
But I think what is important is that we Cannot rely on just one of them (Voltage or percentage) in isolation to assess the state of the battery during flight. Then there are other factors such as temperature, etc.
2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

WetDog Posted at 2016-2-7 03:56
I'm pretty sure you are correct.  You don't care what your 'percentage' is.  You care that the ESCs  ...

> You don't care what your 'percentage' is.  

Well.... what I'm thinking is that we cannot depend in isolation on just the percentage as the state of the battery in flight. Percentage, i feel, should be used as a "High Level" or general indication, but cannot be trusted in isolation.

Ive seen statements from others  in this forum like " I started with a partially ~60% charged battery and ~3 minutes into the flight, my battery percentage was around 50% when the P3  gave a warning/RTH and the ground came up too suddenly and swallowed it up" Then they expect DJI to shell up under warranty. I may be wrong, but I think that its Pilot Error not to keep an eye on the state of your own equipment.

The fact that some rely on just percentage to think they have enough "Juice" in the battery is getting them into trouble.

> You care that the ESCs will start having hissyfits at a particular voltage and when you are close to that voltage and push the stick hard (or have to counter a wind or whatever) the voltage goes below a critical value and the drone crashes to the ground to avoid damaging the battery.....

Correct. Most ESC's have a cut-off voltage (usually designed to save the battery from being irreversibly damaged) but i'd rather have a damaged battery and save the more expensive P3 to land safely even if the voltage per cell goes below 3v at which point the $150 battery is almost most certainly damaged but the +$900 P3 is saved.
Oh... and i'd want the P3 to go crazy with red warnings and beeps when the voltage dropped anywhere below a constant 3.30V under load - but not fall out of the sky.
(why 3.30V? - im no battery expert, but i read many Manufacturer spec indicate that below 3.00v a cell will get damaged or become unstable, so 3.00 + some margin=3.30<- but that exterme case!) - anybody please correct me if im wrong.

I don't know if the P3's have a ESC Cut-off Voltage, or what it is...., DJI-Ken, Or Partrick Or anybody else. Do You Know?s

> I ALWAYS have the voltage displayed and typically look at the aircraft battery screen a couple of times per flight.

Good Man! - That is what we should all be doing.

> You also have 31 cycles on that battery - have you deep discharged it?

The battery was Deep cycled around 7 charges ago, so yes it probably needs another cycle in 3-4 charges, maybe earlier...,
But the point is... How Many Times Do you think that (a novice for example)/we keep a "Strict" Deep cycle regime.  I know somebody who had just flown a Hubsan X4 and subsequently bought a P3 who didn't know what deep cycling was. (did not carefully read the manual).




2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

Here's another Question.....,

What is Deep Cycling actually meant to do?

- Is it to extend total pack life.?
- Is it to extend Usage/Flight time per charge.
- Is it just to recalibrate mAH in and mAH out so percentage indicator, only, is more accurate?
- something else?
- Combination or all above.?

Anybody know?
2016-2-6
Use props
Michael M
First Officer
Flight distance : 1984898 ft
Canada
Offline

dji-p3p1 Posted at 2016-2-6 17:14
Here's another Question.....,

What is Deep Cycling actually meant to do?

Reset the battery because of battery memory. You are supposed to do it with your phone too
2016-2-6
Use props
Michael M
First Officer
Flight distance : 1984898 ft
Canada
Offline

dji-p3p1 Posted at 2016-2-6 17:14
Here's another Question.....,

What is Deep Cycling actually meant to do?

Reset the battery because of battery memory. You are supposed to do it with your phone too.

I have also been able to re create this.
2016-2-6
Use props
Michael M
First Officer
Flight distance : 1984898 ft
Canada
Offline

Sorry double post, this forum messes up sometimes
2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

[RCG]Balthazar Posted at 2016-2-7 07:38
Flying on partially charged batteries have NEVER EVER been a problem before.
Following the battery % ...

> Flying on partially charged batteries have NEVER EVER been a problem before.
> Following the battery % was NEVER EVER a problem in the P1's and P2's I've ovned.
> Same goes for cold weather: NEVER EVER a problem before.
> By now a few people in here has probably notices that I'm not exaggerating when I claim to have THOUSANDS of Phantom flights under my belt.
> Neither would it be an understatement claiming to be a BIG fan of the Phantom Series.
> Those who doubt my experience feel free to do so or have a look at my
Phantom Blog , My Parrot Blog or spy on my Facebook Profile (Pictures, comments and group memberships etc)


Ok, Cool. I agree the Phantom series, now the P3 is awesome, I cant wait to find out what the P4 will be capable of!
(my list of wants is for it to make Barista Style Coffee "Short Mac" for me, each morning, and then locate me and autonomously fly to my bedside or wherever I am and serve it!   of course i expect it to use collision avoidance, to aviod spilling the coffee, whilst getting it to me. ) - all this before automatically self charging to ensure that battery condition is not a problem.

> DO NOT TRUST THE % UNDER ANY CIRCUMSTANCE WHEN FLYING A P3!

I Wholeheartedly Agree!.., Is there any other indicator you use besides looking at the Voltage?

> The battery problems seems to have more or less vapourized after firmware 1.6 though, at least there's a lot less reports about battery issues after that.
> It addresses balance charging, sets a limit to battery takeoff temp and also limits max throttle depending on the battery temp.


I agree to that - It does seem to have reduced batt issues especially those that fly in colder weather. Here in Australia, we don't really get the "Luxury" to fly in the cold, so, batt temp, its less of an issue for us.

> Have you updated your RC, Drone and Battery Firmwares?

Yes.. All on latest, except for GO on my ipad is on 1.4 (for obvious reasons - or until GEO is better defined/implemented)




2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

Michael M Posted at 2016-2-7 12:19
Reset the battery because of battery memory. You are supposed to do it with your phone too

Michael - I understand it resets batt memory..., But the question is what exactly in memory. is it the memory to do with AH in/out etc. and what is the objective. i.e reset of the AH in/out would result in recalibration of the Percentage value (but not necessarly) incresae life of the pack or extend flight times?


> I have also been able to re create this.
Cool, good to know im not the only one.




2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

Michael M Posted at 2016-2-7 12:20
Sorry double post, this forum messes up sometimes

No probs - happens to me too.

You can delete double posts.
- Edit your duplicate post and Go to "Additional options" LHS below the post and then "delete this post" from the options presented.
2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

RodB Posted at 2016-2-7 08:54
How are charging cycles calculated , is a cycle from very low  to full charge or are top ups from s ...

Good Question!

So if a pack is run in the P3 from 100% to 90% then removed and  charged to full.. Would that be considered a Charge Cycle?  - If not/yes what are the thresholds.?
2016-2-6
Use props
Michael M
First Officer
Flight distance : 1984898 ft
Canada
Offline

dji-p3p1 Posted at 2016-2-6 17:30
Michael - I understand it resets batt memory..., But the question is what exactly in memory. is it  ...

im not sure. i know when my phone is dying too fast u drain the batt and charge it up again and it works. reseting the p3 battery i notice increases the battery kife percentage which neans you have more battery
capacity. dunno why or how this works i just kniw it does from experience.
2016-2-6
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

Michael M Posted at 2016-2-7 13:33
im not sure. i know when my phone is dying too fast u drain the batt and charge it up again and it ...

Ok - Then the question is to the wider forum/group and DJI Admins.

DJI-Tim : You did a Fantastic Job on explaining the Battery Power System design. (I liked your article) Do you (or anybody else) know:

  - Exactly what does Deep cycling do and what does it achieve by doing what it does?
  - What is the ESC cut-off voltage for P3?
  - Would are the parameters for one Charge Cycle?


2016-2-6
Use props
[RCG]Balthazar
Second Officer
Flight distance : 475371 ft
Norway
Offline

Updated firmwares

dji-p3p1 Posted at 2016-2-7 02:26
> > Have you updated your RC, Drone and Battery Firmwares?
Yes.. All on latest, except for GO on my ipad is on 1.4 (for obvious reasons - or until GEO is better defined/implemented)

Room for improvements making the great bird even better then
2016-2-7
Use props
jonnied2010
lvl.4

United States
Offline

dji-p3p1, I think the P4 will be made in conjunction with the Roomba 980, put the two together in one package and you may even get your coffee!
That model even has the Recharge & Resume function.
http://www.irobot.com/for-the-ho ... tm_content=redirect
2016-2-7
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

jonnied2010 Posted at 2016-2-8 00:24
dji-p3p1, I think the P4 will be made in conjunction with the Roomba 980, put the two together in on ...

Oh Man! - P4 with Full Autonomous flight, Coffee making and serving, auto charging dock-on as well as Home Cleaning!!!... awesome!

Only one problem - What if my home is in a NFZ?  

2016-2-7
Use props
craig.flash-pho
lvl.1

Germany
Offline

I fear this is what caused my 3 day old phantom 3 pro to hit the trees and brick itsel. I'm so depressed right now.
2016-3-22
Use props
AG0N-Gary
Captain
Flight distance : 700846 ft
United States
Offline

Battery memory is a chemical thing, not a software memory thing.  Lithium based batteries are much better than NiCD or NiMH batteries, but they still have a little memory.  If you constantly use it from say 100% to 50%, it may start thinking that what is 50% is about depleted.  Deep cycling now and then "reminds it" that it can go much deeper so you'll be able to get wider range of use.  This is, of course, a very simplified explanation.
2016-3-22
Use props
pgrover516
Banned

United States
Offline

Tip: the author has been banned or deleted automatically shield
2016-3-22
Use props
dji-p3p1
Second Officer
Flight distance : 534970 ft
Australia
Offline

AG0N-Gary Posted at 2016-3-23 14:35
Battery memory is a chemical thing, not a software memory thing.  Lithium based batteries are much b ...

Hey Gary

Agreed LiPoly Chemistry at best is difficult to understand.

I am no battery expert, but from what I have read/researched, I think the the app tries to report the (percentage capacity) chemical status of the battery, using a software algorithm to quantify how much power has gone in, and how much comes out during use. i.e. what goes in must come out minus some efficiency factor because no battery is 100% efficient.

The issue, I think, is that when a battery is partially discharged and then left for a while, some self discharging occurs which the software algorithm cannot take into consideration (its almost impossible because there may be too many factors like Temperatures, pressure, duration etc...) and hence, when the battery is re-used without charging, what the software thinks the battery has got is not actually what the battery has.

So when such a battery is re-used the software algorithm reports a battery percentage that is not aligned with the True Chemical Charge status of the battery.

Thus an "Unskilled" pilot  flying with with this SW/Battery dependency in place can easily get caught out and suffer a sudden/unexpected RTH type behaviour (depending on settings) or a crash, due to a battery depleting earlier then expected or reported by the app.

Topping up a bettery fully, brings the software back to the maximum memorised state from the last deep cycle.

Deep Cycling, in simple terms, brings the SW status and battery chemical status back in sync. so the percentage status indicator reflects as close to the actual status as possible.

I'm not sure if the Software Algorithim takes into account the battery voltages (which can vary a lot during flight when the battery is put under load) but it would be good if the SW could somehow average it out and take it into account as well. (for all i know it may do already)- does anybody know?




2016-3-22
Use props
AG0N-Gary
Captain
Flight distance : 700846 ft
United States
Offline

Believable theory, makes sense.
2016-3-22
Use props
Antares Fortune
lvl.3
Flight distance : 410499 ft
United States
Offline

Just read this.  Good information to know.
2017-10-6
Use props
solentlife
Captain
Flight distance : 1087530 ft
Latvia
Offline

dji-p3p1 Posted at 2016-2-6 17:14
Here's another Question.....,

What is Deep Cycling actually meant to do?

Deep Cycling wastes battery life and is a myth ....

Even DJI do not advise it any more ........... trouble is - someone forgot to update moderators and also change the owners manual .... but Battery manual no longer has it in.

1 battery cycle is based on a full charge amount. So partial charges only increment when total equals a full charge.

Nigel
2017-10-6
Use props
solentlife
Captain
Flight distance : 1087530 ft
Latvia
Offline

dji-p3p1 Posted at 2016-2-6 17:30
Michael - I understand it resets batt memory..., But the question is what exactly in memory. is it the memory to do with AH in/out etc. and what is the objective. i.e reset of the AH in/out would result in recalibration of the Percentage value (but not necessarly) incresae life of the pack or extend flight times?

Its a crock !!

The so called resest is just where people attribute a slight increase in battery mAh displayed in GO to having recalibrated the battery ... its crap !

What happens is the mAh display is just that ... because battery has received a full charge - it behaves itself for one or two charges ... then reverts to former self.

LiPo's are NON recoverable from any damage ... increased internal resistance etc. PROVEN FACT.

Nigel
2017-10-6
Use props
Genghis9
Captain
United States
Offline

solentlife Posted at 2017-10-6 09:32
Deep Cycling wastes battery life and is a myth ....

Even DJI do not advise it any more ........... trouble is - someone forgot to update moderators and also change the owners manual .... but Battery manual no longer has it in.

solentlife,
Please explain all of the best practice for using, caring, and storing your P4 series smart batteries?

-Is it OK to fully charge a battery, go fly, and drain it down to 5 to 30% then store it for a week or a few days to then fully charge it again for use?

-Is it OK to fully charge a battery, go fly, and drain it down to 5 to 30% then charge it back up to about 50 to 55% for storage for several days or weeks?

-Is it OK to fully charge a battery and then store it for a few days or weeks, why or why not?  
--If done, will it be OK to fully charge it before use?  
--If done, how long can you safely wait before using it and still have an expectation that it will accurately show battery level?

-Is it OK to store a battery long term at 5 to 30%, why or why not?

-What is the most dangerous thing you can do with a battery?

-What is the most dangerous or damaging thing you can do with a battery in using it with the UAV?

Please add anything needed to fully answer the first request/question?
2017-10-6
Use props
CineView Media
First Officer
Flight distance : 4108484 ft
  • >>>
Norway
Offline

The safest and most accurate way to measure power, is mah, its one unit in, one unit out, always.
So if you charged 3500 mah, you know you have at least 3500 units before it hits previous level, eg 20%
% and V is just stipulated based on current draw.
2017-10-6
Use props
Zippo43
lvl.4
Flight distance : 387126 ft
United States
Offline

CineView Media Posted at 2017-10-6 11:28
The safest and most accurate way to measure power, is mah, its one unit in, one unit out, always.
So if you charged 3500 mah, you know you have at least 3500 units before it hits previous level, eg 20%
% and V is just stipulated based on current draw.

One thing has not been mentioned here  :  If your battery is hot from use....Before you put it on the charger...you must let it cool down  "Right" ?
2017-10-6
Use props
CineView Media
First Officer
Flight distance : 4108484 ft
  • >>>
Norway
Offline

Yes, always a good idea to let it rest for 10-5 mins first. If its too hot, it wont start charging either...
2017-10-6
Use props
solentlife
Captain
Flight distance : 1087530 ft
Latvia
Offline

solentlife,
Please explain all of the best practice for using, caring, and storing your P4 series smart batteries?


I don't have a P4 ... but LiPo's are LiPo's regardless of model.

-Is it OK to fully charge a battery, go fly, and drain it down to 5 to 30% then store it for a week or a few days to then fully charge it again for use?


30% is the generally accepted minimum storage level of any LiPo. Taking a LiPo down to 5% is risking damage and each time you do that is accumulative damage. If you fly to 30%, once pack is rested - you often see it rise to 35% or more. That's fine for storage ...

-Is it OK to fully charge a battery, go fly, and drain it down to 5 to 30% then charge it back up to about 50 to 55% for storage for several days or weeks?


Some people do .. personally I see no reason to do that unless the flight took battery below 30%. If less than 30% ... then charge to over 30% is advised to bring pack into at least minimum storage range.

-Is it OK to fully charge a battery and then store it for a few days or weeks, why or why not?  


This is the LiPo horror story ... fully charging and then not using. ANY length of time a LiPo is fully charged and stands - it starts to damage the cells. It does not magically wait so many days and then start. But it is generally accepted that a fully charged LiPo can be left for a day or so ... often the case with RC flyers who charge up night before / have unused packs and then fly 2 or 3 days later. BUT with DJI packs of course we have user settable auto discharge. I suggest that using DJI default of 10days is not good. I suggest a better setting is for battery to start auto-discharge 2 - 3 days after standing.
Another misunderstood point of the auto-discharge. It discharges to about 65% and then  keeps going ! It does not stop ... In fact it will keep going until it enters HIBERNATION MODE ...
Therefore it is suggested that battery be checked every few weeks if left for long periods.

--If done, will it be OK to fully charge it before use?

Of course ... first switch on battery - THEN plug in charger ... this then makes sure charge is applied if battery is down in the lower 90% range.

--If done, how long can you safely wait before using it and still have an expectation that it will accurately show battery level?


Personally I do not trust any supposed display figures in GO / Litchi / DJI ... I prefer to check battery with multi-meter.
Before flight - even if battery has only sat for one day charged and not entered auto-discharge ... I switch on and plug in charger to be sure battery is at max charge before flight.

-Is it OK to store a battery long term at 5 to 30%, why or why not?


Not at that level of lower than 30% ... accepted range of storage for any LiPo, normal or HV as DJI are ... is 30 - 60% of charge level.

-What is the most dangerous thing you can do with a battery?


Shorting out these ... as LiPo's have incredible capability of discharge rates and can erupt into fire. They need no oxygen supply as shown by various online videos. Another is puncturing the foil envelopes or subjecting them to heat such as leaving in the window of a car / home in direct summer sun. Over-charging or using wrong charger settings.

-What is the most dangerous or damaging thing you can do with a battery in using it with the UAV?


Basically being stupid with it ... treat it with respect and follow the useage guidelines and should be ok.

Please add anything needed to fully answer the first request/question?

Nothing much to add really ... except if you use your DJI batterys to their full capability ie fly till about 30% ... then you should experience good return on your investment. I would also suggest getting hold of a Telsin Discharger. These are great little gadgets that you can use to transfer 'energy' from the DJI battery to cell phones / other USB items instead of just wasting it through resistive discharge. Auto-discharge is what is termed Resistive Discharge : The energy is dissipated through resistors and wasted as heat.

I understand that some may not agree with my info - that's up to them. My info is based on extensive use of LiPo's in all manner of RC and other uses. I have also dismantled DJI batterys as well as many others to understand their workings. Much of this in conjunction with other like-minded persons and compared findings.

Act Safe - Be Safe.

Nigel
2017-10-7
Use props
Genghis9
Captain
United States
Offline

solentlife Posted at 2017-10-7 03:37
solentlife,
Please explain all of the best practice for using, caring, and storing your P4 series smart batteries?

solentlife
Thanks!  Very helpful and useful!

Need to clarify a couple of points you made.
-So, you are saying that anytime you take a batt down below 30% you are damaging it?

-Please clarify, if you fully charge a batt, how long can you safely wait before using it?  
--You stated it damages them, but then walked it back as you said if used in a day you are OK, I think?
--Exactly how long would you wait to use a fully charged batt?

-How are you able to check a DJI batt with a multi-meter?
--What are the parameters/levels you are checking, when checking them this way?
--I assume that those readings are reliable, then how do you apply them as compared to what you see on the app i.e. how do you reconcile the difference?

I greatly appreciate your time on this, it is very helpful!
2017-10-7
Use props
solentlife
Captain
Flight distance : 1087530 ft
Latvia
Offline

solentlife
Thanks!  Very helpful and useful!


As I say - some do not agree with me .... but that's not my problem !

Need to clarify a couple of points you made.
-So, you are saying that anytime you take a batt down below 30% you are damaging it?


No - what I said is taking it down to 5% is damaging it. Going below 30% is below generally accepted minimum storage level. We do and I occasionally fly till below 30% ... but I then bring battery back up to above 30% as soon as possible after.

-Please clarify, if you fully charge a batt, how long can you safely wait before using it?  

Personally I only accept that for that day. If I charge today and then actually fly tomorrow - I will for caution sake if possible switch on battery and plug into charger tomorrow to be sure. I like to be sure on day of actually flying.

--You stated it damages them, but then walked it back as you said if used in a day you are OK, I think?

We have to be practical about this ... the battery suffers damage as soon as you have it charged ... and the damage accumulates over time. But how can you avoid a days being charged if you want to fly ?

--Exactly how long would you wait to use a fully charged batt?

This is basically already answered ... I don't like using a battery that has sat for a day since charged.

-How are you able to check a DJI batt with a multi-meter?

Switch on and read voltage via the large main contacts. Full charged is 17.4V

--What are the parameters/levels you are checking, when checking them this way?

Purely total voltage as that's only information you will get from the main contacts. Compare to the LiPo Fuel Table and you know what % state your battery is but unfortunately you cannot check individual cells.

--I assume that those readings are reliable, then how do you apply them as compared to what you see on the app i.e. how do you reconcile the difference?

I trust my MM more than Go !! Reconcile ? Why ? I want to know battery state.

I greatly appreciate your time on this, it is very helpful!

No problem. The more people understand or appreciate about LiPo's the better.

I wish that DJI would do as majority of RC world does and allow us to look after our batterys instead of closing them up and preventing access. I can do a better job of maintaining LiPo's with my common over counter LiPo chargers etc. - than their so-called intelligent board. But of course theh they would lose a revenue stream !

Cheers
Nigel
2017-10-7
Use props
Genghis9
Captain
United States
Offline

solentlife Posted at 2017-10-7 10:24
solentlife
Thanks!  Very helpful and useful!

Again thank you!

Yes, well when you come from a culture of full control by the governing authorities, but then given a certain level of economic freedom in business ventures it is not uncommon to see a person run their company in a similar manner to their life and society.  More control is good because it leads to more required sales from them.  However, sooner or later it does bite them back as folks will either find work arounds or gravitate to more customer friendly companies (if/when they have a competitive product) or both.  These days, technology wise, it is difficult to keep the genie in the bottle.
Cheers!
2017-10-7
Use props
wehill1439
lvl.1
Offline

dji-p3p1 Posted at 2016-2-6 16:36
> You don't care what your 'percentage' is.  

Well.... what I'm thinking is that we cannot depend in isolation on just the percentage as the state of the battery in flight. Percentage, i feel, should be used as a "High Level" or general indication, but cannot be trusted in isolation.

Wetdog posted the above:  Ive seen statements from others  in this forum like " I started with a partially ~60% charged battery and ~3 minutes into the flight, my battery percentage was around 50% when the P3  gave a warning/RTH and the ground came up too suddenly and swallowed it up" Then they expect DJI to shell up under warranty. I may be wrong, but I think that its Pilot Error not to keep an eye on the state of your own equipment.

The fact that some rely on just percentage to think they have enough "Juice" in the battery is getting them into trouble."

I'm new to drones.  I started learning about flying and understanding my new Phantom 4 Pro about three weeks ago.   I started reading the manual and watching every youtube I could find that I thought would help me understanding the Phantom.

I just discovered the issue with relying on the percentage today.   I learned it because there is lots of confusing information in the manual and on these message boards.  So, I went to DJI  Chat this morning and asked questions about how to care for my batteries.  I wasn't smart enough this morning to ask the question about using the percentage versus the voltage of the battery cells.

In all the reading of the manuals etc did I come across any information regarding this issues -- watching the percentage versus watching the voltage.  So, my guess is that all of the Phantom pilots who use the percentages as their guide never found any information in the manuals or elsewhere.  I'm not stupid and had I not been concerned about how to protect the health of my four batteries I would never have come to that conclusion.

There are lots of holes in the DJI manuals.  Some of the important parts of the manual are not well written.  The same with the DJI videos on their site.  I think the DJI videos are more geared on selling then it is on learning.  

I spent five days last week out in the boonies of the Oklahoma Panhandle flying where there are few obstacles and lots of open spaces to fly without worry.  I discovered so many neat things about the drone that were never touched by the manual of videos.  Of course I am inexperienced with drones and flying in general.  

I'm not trying to complain, just trying to figure out how to unlock all the great features of the Phantom and also to fly safe and in a manner to take care of my drone and all the accessories.

This is a really good site and lots of good information here.

2018-8-3
Use props
Mark The Droner
Captain
Flight distance : 2917 ft
United States
Offline

Research is a good thing.  

As stated in the summary of the OP, always launch with a fully charged battery.  If you do that, everything will be fine.  

Good luck.
2018-8-3
Use props
solentlife
Captain
Flight distance : 1087530 ft
Latvia
Offline

WetDog Posted at 2016-2-6 08:56
I'm pretty sure you are correct.  You don't care what your 'percentage' is.  You care that the ESCs will start having hissyfits at a particular voltage and when you are close to that voltage and push the stick hard (or have to counter a wind or whatever) the voltage goes below a critical value and the drone crashes to the ground to avoid damaging the battery.....

I ALWAYS have the voltage displayed and typically look at the aircraft battery screen a couple of times per flight.

Forget the old crap about deep discharge .............. the only benefit is to reset the battery board chip ... it does nothing for the battery.

Voltage drop is the killer in this scenario .................. I've posted many times on this.

Nigel
2018-8-3
Use props
Sayhelloforme
Captain
Flight distance : 8133219 ft
United States
Offline

Thanks for the post fantastic information   
2018-8-4
Use props
12Next >
Advanced
You need to log in before you can reply Login | Register now

Credit Rules