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Actual LiPo used in DJI Intelligent packs ? High Voltage LiPo or ...
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solentlife
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I have just been told that the DJI battery in the P3 series is a High Voltage LiPo, not the standard 4.2v per cell variety.
The LiPoHV format is 4.35v per cell and requires a charger with LiPoHV mode ... I have 3 that are ...

Can DJI confirm what the LiPo's are in these packs ... standard 4S or High Voltage 4S ?

Thanks
Nigel

2016-12-4
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fans913aa526
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Hello Nigel,
They are 4S HV LIPOs. Please refer to my reply to "Storing P3S" thread. More info there.
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solentlife
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Tks ... much appreciated.

Nigel
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I am disappointed having thought that a rep of DJI on here might answer and clear the air ?

Having trawled the web, read all the docs I can find from DJI - all I see is the nominal 15.2v number which applies to both standard and HV LiPo's. Not very helpful at all.

C'mon DJI - answer the questions :

Are all DJI Phantom 3 batterys High Voltage LiPo's ?
Is it true that DJI have coded the latest FW so that 200 cycles of the packs is maximum ?

Nigel
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RedHotPoker
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Hope this helps you to understand the built in complexity

DJI-Tim shared this awesome info...http://forum.dji.com/thread-38174-1-1.html

How do Intelligent Batteries Work?
The Inspire 1’s intelligent battery has many functions: Battery Level Display, Battery Life Display, Auto-discharging, Balance Charging, Over Charge Protection, Temperature Detection, Over Current Protection, Short Circuit Protection, Battery Cell Damage Protection, Battery Information History, SleepMode, and Communication.

Some functions can directly display the current state of the battery by checking whether an LED is on or off, while other functions of the battery can only be worked with DJI GO app. The app displays how much remaining power the battery has,and the system can automatically analyze and calculate the power and time required to return home and land safely, so that users will not always worry about a low battery during flight. The Intelligent Battery also displays the voltage of each battery cell, the total charging and discharging times, the health status of the battery, and so on.   


There are some advanced functions, like the Inspire 1’s Smart Low Battery RTH:
When the Battery Level Indicator displays a low battery warning, the motor is not able to output enough power. Users are advised to land the drone immediately, otherwise the drone will land automatically. An automatic landing may damage the drone, endanger by standers, or cause other problems. To prevent such hazards, when low battery is triggered, the main controller of Inspire 1 can intelligently estimate whether the current power level is enough to return home from its current position. The DJI Go app will advise users to return home if this is the case. The drone will automatically return to the Home Point if no action is taken within 10 seconds. Users can cancel RTH by pressing the RTH button once. Smart RTH will only work once per flight.
Compared with a traditional battery, intelligent batteries bring pilots great convenience. Let’s see how the battery, a basic energy storage medium, developed into a multi-functional intelligent battery by looking at some of its special functions more closely.

Over Discharge Prevention
When using a battery, users often worry about over discharging. To avoid the problem, battery designers installed an over discharging protective circuit. Discharging will stop when battery reaches a preset voltage. However, if discharging stops, lots of data cannot be processed, and the drone will lose power. Hence, automatically stopping discharging is the last level of battery protection; the battery circuit also calculates the endurance of battery life and warn users to take safety measures when necessary.  
For example, the Inspire 1’s battery data is integrated with its flight control data, which can provide three level battery warning protection.

1.    Low Battery Level Warning - When the battery level indicator displays that the remaining battery level is 30% (the exact percentage can be set by users), the red light starts slowly flashing. Users are notified of the remaining battery level and should returnto the Home Point as soon as possible.
2.    Critical Low Battery Level Warning - The drone will automatically return to the Home Point if the remaining battery level can only support the drone’s return home. The thresholds for the warning are automatically determined based on the current flight altitude and distance calculated with intelligent battery data and the flight control data.
3.    Intense Critical Low Battery Level Warning - The drone will automatically land if the remaining battery level cannot support a normal RTH (return time being delayed by headwinds, for example) to avoid crashing.


The endurance of battery life is determined based on the current flight distance, altitude, and current output power of the motors. Since these elements are dynamic, all data should be calculated in real time. All this requires exceptional battery cell management and algorithm design.

Battery Charge Protection and Storage
There are some special requirements for charging lithium batteries. Currently, lithium batteries use serial-parallel battery cells. But since battery cells are different, this leads to imbalanced charging and discharging. Therefore, it is necessary touse a charging management circuit. Another function of the Intelligent Lithium Battery is that it has an intelligent charging and discharging management system.
The Inspire 1’s intelligent battery can manage the charging and discharging process, and it is also able to automatically discharge. The battery will auto discharge to around 65% if the battery level is more than 65% and it is idle for more than 10 days (users can set the exact time themselves).

Checking Battery Level in Real Time

Users used to check battery levels, output voltage, and electricity by using a multimeter, or mounting a “beep-beep” tool into the battery, which was inconvenient. Today, batteries are more intelligent and display the remaining battery and other information in real-time.

Take Inspire 1’s battery as an example:
1.  You can check the remaining battery level easily. 4 LED lights display the current remaining battery level in real-time on the ground and in flight.
2.  The DJI GO app will display the cell voltage of the battery by transferring voltage data from the aircraft in real time.
3.  A record is stored about the battery’s history, detailing the number of uses, previous warning messages and battery life over time.
4.  The Inspire’s LED light displays battery errors. It will display errors caused by short circuiting,over current charging, over voltage charging, high temperatures, low temperatures, and so on.
Here are two examples of intelligent battery functions: battery level display and charging protection display.
Battery Level Display:


No Contact Plugs

Imagine you are mounting a battery onto a DIY drone, the plug sparks. If the situation happens again, the plug will oxidize under the high temperatures when the battery discharges. The conductivity of the plug will decrease, and the plug will overheat and dissolve. Some crashes are caused by the aging electrode plugs. To solve the problem, the Intelligent Lithium Battery’s management circuit was developed.


When placing the battery into Inspire 1, the electrode contact will not discharge, so there will not be any electric erosion. As such, the life of the battery plug contact point increases. The battery will output power only after pressing the on/off button. When powering off, users should press the power button twice, and hold it the second time.


Battery Authenticity

The intelligent battery's authenticity is well protected. First, users can only use lithium batteries produced in the original factory, so the quality of the battery is guaranteed. Therefore,users must only use batteries produced by the company, or else the aircraft will not takeoff. Even if the system can be cracked, the company can upgrade the firmware accordingly.

The 5 points above explained more about the battery, battery pre-check before flight, battery storage and the benefits of protection so users can use their batteries more safety. The next section will discuss battery guidelines and notices.
 
Battery Usage Instructions
1.    Please remove the battery from the drone while it is not being used, and keep it in a temperate environment to prevent the battery from over heating or freezing.
2.    Do not charge the battery right after the flight; wait until it cools down. The charging environment should be between 0℃ to 40℃. Take care of the battery to avoid accidents.
3.    Be aware of the battery during transport. A vehicle accelerating or decelerating and may cause the battery may collide with sharp objects and combust or cause other damage. Please keep batteries in a safe place while transporting in a car to prevent fire.
4.    Check the status of battery before using. Lack of usage over may deplete battery power or lead to deviations in voltage level between the battery cells because of incomplete charging and discharging operations. Normally, these problems will ariseif the battery is within a 0.2V voltage deviation.
5.    Please recycle a damaged battery, since lithium batteries are greatly harmful to the environment.
6.      Suitable storage power range is from 50% to 65% if the battery is unused for a long time.
7.    Air transportation is a concern of some users. Some are glad because of that the standard battery level of the Inspire 1 batteryTB47 is 99.9Wh, and can be carried onto a flight, since the limit of battery level is 100Wh. But the standard battery level of the optional battery TB48 is 129.96. Normally, only two of these batteries can be carried onto a flight.
8.    While using the battery under low temperature environment, between -10℃ to 4℃, the internal resistance of the battery increases which leads to heavy drop in voltage. Therefore, please fully charge the battery before using. The voltage of battery cells reaches 4.35V. While the temperature is lower than 5℃, the battery needs to be fully charged, the voltage of battery cells should be higher than 4.2V, and warm-up and heat preservation actions should be taken before launching. The warm-up can be achieved with the battery heater or by hovering the drone at a low altitude for around one minute.

Many users are unfamiliar with complete discharging. For instance, the battery of Inspire 1 needs to have one complete cycle of charging and discharging after ten in complete cycles in order to calibrate the battery level.
There are two modes of discharging: the slow one and the rapid one.
Slow discharging: Install the battery into the drone, turn the battery on and leave it electrostatically discharging until it automatically turns off when the battery level lower than 5%. It is recommended not to turn on the electric motor especially those without rotating propellers, as it may lead to abrasion of the motor.
Rapid discharging: Install the battery into the drone, fly it until low battery level alerts and the drone automatically lands. Do not turn it off and keep it discharging until it automatically shuts down.

Nowadays one of the biggest limitations of the drones is the endurance of the battery. The intelligent battery can be improved to maximize efficiency or use another energy source such as hydrogen or solar energy, to extend the operationtime of the flight. If new energies can be utilized, it will be a huge step forward for the battery since its efficiency will greatly improve.
Thank to those of you who read this whole thread!
Let's look forward to the next revolutions in intelligent battery design!

RedHotPoker
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solentlife Posted at 2016-12-5 11:35
I am disappointed having thought that a rep of DJI on here might answer and clear the air ?

Having  ...

As has already been stated, yes, they are HV LiPos, and you do not need any special charger, because the charge circuitry is built into the batteries. The DJI 'charger' is actually only a power supply.
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Geebax Posted at 2016-12-5 08:47
As has already been stated, yes, they are HV LiPos, and you do not need any special charger, becau ...

Thats fine ... but DJI themselves need to answer as the definitive source.

On another forum there has already been an exchange where the other was wrong along with many others over time .... basically the result of misinformation that became accepted as fact. If DJI themselves would actually answer fully questions instead of taking the 'BMW' style of Company protective stance - such misinformation would not occur.

I now see from RHP's cut and paste of a DJI post in another thread that 4.35V is stated in the text ... Finally DJI have said something that really matters.

As regards the power supply - to be honest I knew that it was only a regulated power brick and was provoking a discussion so people could contribute and maybe benefit from it.

The result now is that a regulated power supply to a LiPo charger capable of charging HV LiPo's without balance lead is appropriate. Warranty issues are accepted.

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solentlife Posted at 2016-12-5 12:52
Thats fine ... but DJI themselves need to answer as the definitive source.

On another forum there ...

I guess you are new here, because DJI do not make a habit of commenting on these technical issues. This is because the people assigned to the forum are not necessarily technical, and have to go and ask someone when these issues arise. Most times you will not get an answer.

'The result now is that a regulated power supply to a LiPo charger capable of charging HV LiPo's without balance lead is appropriate. Warranty issues are accepted.'

What does this mean?
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solentlife
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Hi Geebax ....

First - I run and moderate various forums and I value the members input. I also regard answering questions as part of a forums job. If DJI want to have a forum such as this - then they should be prepared to answer technical and non technical questions. Not only does that add value to the forum but it also reduces the probability of false or misleading information getting promulgated.

Ok - my comment is specific and if you understand the context of the thread self explanatory. But here goes :

The result now is that a regulated power supply to a LiPo charger capable of charging HV LiPo's without balance lead is appropriate. Warranty issues are accepted.


Having delved into the murky world of DJi batterys, the sum of the information now available shows that the 'charger' supplied by DJI to charge the battery is a regulated power brick only. Second that RedHotPoker in pasting the DJI text of another thread here shows that the LiPo in the battery case is indeed as others have commented a HV LiPo. The two points show that a HV Lipo capable charger should be able to charge the DJi battery when suitably set up. I end the line by stating that Warranty issues are accepted - which means I am fully aware of DJI Warranty clauses.

Whether new or not makes no difference ... a Forum is supposed to be an open discussion arena to help and improve knowledge and dissemination of information.

Sorry if I do not meet the norm on this ...

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RedHotPoker
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The info is available if you look for it. Now how you interpret that, well that's up to you.
I only share it, to give you some more information so that you can atleast make an educated decision, about third party charging stations and how these battery packs are supposed to work.
If you destroy or damage your equipment, after having been fully informed, you pay the penalty.

DJI can't be responsible for our use or abuse of the equipment, only if the fault lies in malfunctions, which are out of our control.


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solentlife Posted at 2016-12-5 14:22
Hi Geebax ....

First - I run and moderate various forums and I value the members input. I also reg ...

'The two points show that a HV Lipo capable charger should be able to charge the DJi battery when suitably set up.'

There is no point in connecting any type of sophisticated LiPo charger to a DJI Intelligent battery, it is a waste of time. All the control over the charge cycle is inside the battery and it simply requires a 17.5V 5A supply. There is no external access to the individual cells, so you cannot perform a balancing charge with an external charger. You also cannot charge it any faster, because the battery itself is in control of the process. The main reason for this approach is because there is a small processor on-board the battery that monitors the charge and discharge and is therefore able to quantify the amount of charge applied to the battery and also the discharge, and that information is used to monitor the charge status of the battery and to inform the aircraft and then via the radio link, the operator of the battery condition.

That same internal processor is also responsible for high current charge termination and subsequent balance charge of the cells. It also can perform a timed discharge of the battery to bring it down to a safe level where electrolyte gassification will not occur, as the gas build-up can cause swelling of the battery pack and make it difficult to either insert it in the aircraft or remove it.

With regard to the forum, the DJI staff here have a diffierent role to perform, they monitor customers problems, offer advice and help to make sure issue of repairs and such are expedited. As such, their responses are often cut & paste standard answers. More complex issues are also handled by the members, but questions of a deep technical nature are not usually answered because the DJI design people simply do not take part in the forum. Never have.


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Geebax Posted at 2016-12-4 20:56
'The two points show that a HV Lipo capable charger should be able to charge the DJi battery when s ...

You gotta love these self help groups. Where therapy is handled by the patients themselves. Ha

One Flew Over The Phantoms Nest. Chuckles

I'd rather have a bottle in front of me, than a frontal lobotomy. Snickers

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Geebax Posted at 2016-12-5 11:56
'The two points show that a HV Lipo capable charger should be able to charge the DJi battery when s ...

You really have missed the whole point haven't you.

No-one is arguing about the intelligent part of the battery. No-one is saying we should balance or control it externally.

The point is - whether an external LiPo charger can provide charge power to do the job. Why choose a LiPo charger ? Because I have a bench full of them and I want to use one in my car to charge my pack at the field. I will not pay out for a DJI car charger - when I have 5 chargers already perfectly capable of supplying HV Lipo 4S voltage and also I can set my AMP rate as i deem fit.

My intentiion is to set my Charger to Hv Lipo 4S and at non balance mode Charge, most likely at about 2 to 3A ...  That means the charger will supply straight voltage suitable for a 17.4v Hv 4S LiPo. The battery will still have its intelligent functions working. It should in fact provide greater safety than using a DJI supply via Inverter in fact. Because the charger will be monitoring the voltage and the battery will be ... together there will be no overcharge or risk.

I find it hard to understand why you don't appreciate the concept ?

Let me ask you a question ...

When you have your car repaired or serviced ... do you always use manufacturers items or do you sometimes use 3rd party items ? Do you use exactly the brand and grade of oil stated in the owners manual or do you have your own preference ?

You may think its not related - but in fact that is exactly my point.

Your point about Forum moderators and information - well that's really sad and DJI should maybe consider whether they should move on if they will not give technical assistance in threads. I made a genuine and reasonable request for information at the start of this thread. Something that any normal Forum would have answered.

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RedHotPoker Posted at 2016-12-5 11:34
The info is available if you look for it. Now how you interpret that, well that's up to you.
I only  ...

Yes but not so easy to find when the sources do not give full info.

Every other manufacturer / provider of models that use HV LiPo I have seen - all state clearly in their literature HV LiPo. Until you kindly found and posted the text of the DJI guys post - the fact of 4.35V was only by virtue of those who wanted to know and as far as I see not DJI people.

Sorry if I ruffled some others feathers ... I am only trying to get to the real facts and not the protectionist company propaganda. No disrespect to you RHP ... I am glad you posted that clip.

I am a modeller who has been in this game for many years and I object to protectionist gear. I do not need DJI to show me how to use and maintain LiPo's. I realise that the nature of the Phantom in that any idiot can fly it - means measures need to be taken to ensure safe use. Personally I think DJI has gone too far in this and I also blame the Legal Profession for creating Liability and Protectionism that invades life too often now.

A very good fiend of mine when I lived in UK had a respected and profitable Model Kit business in UK. I flew and still fly models of his. I needed some replacement parts and contacted him to be told that he had closed down some years earlier because the Legal side of Liability had grown so large - the business could not afford it. Terrible that such a respected and knowledgeable Kit manufacturer who had given much to the International Model world should be pushed out because of possibility of some idiot not putting his kit together correctly and maybe causing injury or damage.

So in telling this - shows I understand the Company view, but I also understand the modellers side. There are many like myself who wish to have the technical information so they can safely and successfully provide for their hobby needs. It is not necessary to just throw the Cheque Book at the situation.

Sorry rant over !!

I apologise RHP ... I am not getting at you.

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solentlife Posted at 2016-12-5 15:24
You really have missed thewhole point haven't you.

No-one is arguing about the intelligent part  ...

'Your point about Forum moderators and information - well that's really sad and DJI should maybe consider whether they should move on if they will not give technical assistance in threads. I made a genuine and reasonable request for information at the start of this thread. Something that any normal Forum would have answered.'

Don't shoot me, I am only the messenger. Stick around here long enough and you will find what I said is true. Frankly I don't care, I have made you aware of how it is, how you use that information is up to you.

'You really have missed the whole point haven't you.'

I doubt it. You can use what ever you want to charge your batteries, but as far as the car is concerned, it is hard to beat the cheap voltage doubler supplies you can buy off eBay for about 20 bucks. They do the job very well.

'I find it hard to understand why you don't appreciate the concept ? '

I don't see where I have not accepted any concept, you actually have not put one forward until now. I now understand why you want to use your existing chargers now you have actually explained it. Fine, do so. I was trying to point out that all the DJI battery needs is a raw power supply, if you understand how to supply that requirement then fine.
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Geebax Posted at 2016-12-5 12:43
'Your point about Forum moderators and information - well that's really sad and DJI should maybe c ...

Yes and I understand that so no need to get upset.

Changes to setups or systems only come about by someone starting the ball rolling. I hope that my position can inspire others to post questions and push for answers.

Do you not think it better to get manufacturers correct technical info than some outsiders misinformed versions ?

I joined this forum expecting to find answers and all I see is near zero technical info. Plenty of send back to Service Centre ... but no real 'meat'.

The value of a forum community is the value of the information it provides.

My post style is not to antagonise, but to get people thinking - I'm a true blue Brit and I say what I feel straight and to the point.

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solentlife Posted at 2016-12-5 15:51
Yes and I understand that so no need to get upset.

Changes to setups or systems only come about by ...

'I joined this forum expecting to find answers and all I see is near zero technical info. Plenty of send back to Service Centre ... but no real 'meat'.'

Exactly, that is the point I was making. This is also what is described as a user forum, meaning the users are encouraged, and even expected to provide the help to each other. But historically there has never been any detailed technical information provided by DJI, and in some cases, the little that was provided was technically completely wrong.
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I work in an environment that covers Military, Oil and Shipping ... if I was to accept such then I would not live long. Maybe I expect too much ?

The truth is - that is what my PoV is - to be able to question and expect within reasonable bounds to receive the answer.

Expansion of knowledge requires pushing boundaries. I have a habit of doing that. I was brought up to question and solve. Hard at 60yrs old to change now ...

I wish great flying and successful landings.

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RedHotPoker Posted at 2016-12-4 16:42
DJI-Tim shared this awesome info...http://forum.dji.com/thread-38174-1-1.html

How do Intelligent Batteries Work?

Great explanation.

Do you know what are the DJI specs in terms of charge and discharge parameters?  10C, 20C, etc?

And do you have an idea on the name of the actual battery manufacturer?  This is important to know in order to have an idea of the quality.  Thank you.
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BobBob Posted at 2017-10-1 23:33
Great explanation.

Do you know what are the DJI specs in terms of charge and discharge parameters?  10C, 20C, etc?

We used to know the manufacturers name. It is in the forum someplace.


Not sure about discharge rates though...


RedHotPoker


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quadpilot Posted at 2017-10-2 15:16
so does the firmware stop the battery at 200 charges or not??
and is it the latest firmware version after 1.10.90 that does this ?
or is it just a myth

The displayed battery capacity is not a measured value, it is a calculated value. Therefore, as the battery is charged, the charging circuit must note the quantity of charge that is put into the battery pack, that value then becomes the battery capacity.  When the battery is inserted into the aircraft, the aircraft needs to be able to read that capacity value in order to inform you how much charge you have available.

If the battery was just a dumb collection of cells, and was charged by an external charger, then there is no was to store the capacity value such that the aircraft is able to read it.

Solentlife's experience is based on being a member of an RC flying club that flies out of a field. In nearly all cases, the aircraft that are flying are doing so within the view of the pilot, so that if a battery getsa down to zero, they can glide back to the field safely. Many of those RC control systems do not feed back any form of data about the battery to the pilot. Some do, but not usually in the context of a capacity figure. And those aircraft do not have the ability to return home when the battery is low.

DJI make aircraft for the masses, not RC enthusiasts, and they quite correctly assume their customers are not expert in battery systems, so they build the intelligence to manage the battery into the battery itself, where it (mostly) does an excellent job.

And these aircraft are very often flown a long way from the home field, so the RTH function is critical to the survival of the aircraft. Therefore the aircraft needs to know its calculated battery capacity, and along with real-time measurements of the battery voltage, it enables it to determine when to take action to save the aircraft from loss.
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quadpilot Posted at 2017-10-2 15:49
hi geebax
but my question to the 200 charge cut off is not answered

'it's as thought the on board charger shuts down before the complete charge to save an over charge situation'

It is quite possible that it does exactly that.

'then why does the go app show 97/98% battery capacity '

In truth, the remaining 2 or 3 percent mean nothing. The battery has told the charging circuit it is fully charged, and that is the main thing. We do not actually know if the cells are given a balancing charge at the finish of the high rate charge, that could easily account for the remaining 2 or 3 percent.

'but my question to the 200 charge cut off is not answered'

I seriously doubt that. There are many, many unfounded rumours posted by people who don't have a clue, and this looks like one of them. Having said that, if my flight battery got to 200 cycles, I would give consideration to retiring it and getting a new one. Use the olod one for ground testing or such.


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quadpilot Posted at 2017-10-2 17:57
ok thanks Geebax for you positive answers one day
batteries will get even better.
but when you think back to the early days of battery power flight

Yes, quite true. The real problem is that these batteries are chemical devices, and their performance can vary according to how they are handled and looked after. If you treat them with care, they will give you relatively consistent results.
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quadpilot Posted at 2017-10-2 15:16
so does the firmware stop the battery at 200 charges or not??
and is it the latest firmware version after 1.10.90 that does this ?
or is it just a myth

I do not know if it stops the battery.  Never reached that point.  I do not think so.   It will depend on you.

The battery software derates the charging capacity using some equations based probably on battery life.  And battery life has another formula that depends on total number of charging cycles.

To get 100 % regardless of the current total capacity, you can do 2 things:

a) One is to discharge it to less than 8% or about,  as explained on the manuals  OR/AND

b) Attach the charger to the battery, then turn on the battery.  Even if the battery is full, it will charge during some short time.  If you have time and patience you can repeat this many times as you want.  This will help to get your battery at 100%, whatever this absolut number be.
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OK .. I started this thread quite a while back and since then having opened ... diagnosed ... investigated DJI battery packs ... I have basically found out answers that many do NOT agree with the accepted views / info put out.

To Quadpilot about the 200 cycles : I was in discussion with DJI TEchs and they stated that the 200 cycle life was a limit imposed via FW. The battery itself could in fact still be perfectly good. The limit was removed from FW and they say we should be able to fly well past that 200 cycle point.
Second the cycles are based on incremental calculation of charge replenishment. Therefore a partial charge will not increment 1 cycle but a partial ..

Balancing of cells : This in fact is the worst point of all ... that the charge system used does not in fact balance fully any pack regardless what you do. The charge controller board in the battery will shut down power to it once total voltage reaches limit. It does not enter a proper balance format as normal LiPo and chargers do.

Deep Discharge : This is another myth and wastes battery life. The so-called calibration of cells by doing it is rubbish as all it does when you charge back up is possibly bring up a lazy cell giving the impression of capacity recovery. Go fly again a few times and see the pack revert to former !

100% of charger : NO battery ever reaches true 100% ... the charge stops when 100% voltage is detected. Disconnect and the battery will lose a few degrees temperature, will rest and you get the reading 97 - 98% ... simple fact.

Geebax - with great respect - mentions I fly conventional RC with LiPo's and chargers. True. But that in itself creates an environment that teaches a lot about LiPo and their working. I agree that DJI have chosen to produce a system that 'idiots' are hand-held with regard to LiPo's. DJI decision and battery system is to cater for those less educated on LiPo ... NOT because DJI products fly out of sight etc.
It has nothing to do with glide or falls like a brick ... its purely DJI holding hands of the less informed.

The DJI charge control board on the batterys is not as clever as people think - but it does a job. If DJI allowed us to charge / administer our batterys as vast majority of RC models are - we could do a much better job of looking after the packs ... but I don't think DJI are ready to change.

Final point .....

Charge rate of P3 batterys runs in the 1C region. All you need do is read the amps output of your charger label vs the capacity of the battery.

Discharge rate of the P3 battery actual is in the region of 70% 4800mAH in 18mins .... giving a C rating of approx 3.5C.

If we could replace the cells in the packs ... I would suggest based on the above ... LiHV 4S 4800 - 5000mAh 20C .... would be more than good enough.

But DJI have decided we cannot.

Nigel
2017-10-3
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solentlife
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BobBob Posted at 2017-10-2 21:02
I do not know if it stops the battery.  Never reached that point.  I do not think so.   It will depend on you.

The battery software derates the charging capacity using some equations based probably on battery life.  And battery life has another formula that depends on total number of charging cycles.

1. DJI have revised their deep discharge info and no longer advise this. It has been removed from some manuals but unfortunately not all and moderators still cling to the old idea of deep discharge. It is not current DJI recommendation.
It will not recover lost capability.

2. Repeated charge top-up with battery switched on will give slightly better charge level - but as you keep repeating - battery temperature will rise and increase resistance to charge. You will never reach 100%.

Nigel
2017-10-3
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solentlife
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"so what you are saying here is don't top up the battery whilst it is switched on leave as a normal charge and fly?"

No - what I am saying is in reply to other guy who says repeated charging switched on will reach 100%. Not possible. BUT I do agree that switching on gives best charge possibility and is what I do ... but I do not keep repeating to try and get 100% ... I do once and then fly.

"do you know from what version F/W it was removed from ref this 200 cycle business  or should i just ignore the myth
and fly happy"


No - Tech never said which FW it was removed ... but I would not worry about it ... just ignore it and go enjoy flying !

"can you tell me if i have batteries that are 30% capacity left and i want to charge to 45% to store them for 2/3 weeksand the app shows battery charged 5 times each time i top up to 45% that will count a a charge and the app will increment
the charge amount to 6 and so on"


If you fly to 30% ... once rested - the battery will probably recover to about 40% ..... there is no need to charge up to 45% to store. The 30% is fine for storage as its in the lower accepted storage range. Storage is good from 30 - 60% ... with preference in the lower ranges.
Cycle increment 1 from mine and others observations when we compared notes indicated that only a full charge or combination of partial charges adding up to a full gives 1 cycle.

To be honest - I think people worry about this too much ... not least because of the mis-information that keeps getting posted on forums etc. and gets accepted as gospel. LiPo's are LiPo's regardless of DJI's control board etc. Trouble is DJI board has removed the user access to the battery ....

Myself and another are looking into modification to allow user maintenance of the actual pack ... but due to DJI forum rules - it will have to be promulgated elsewhere.

Nigel
2017-10-3
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BobBob
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Peru
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solentlife Posted at 2017-10-3 01:20
1. DJI have revised their deep discharge info and no longer advise this. It has been removed from some manuals but unfortunately not all and moderators still cling to the old idea of deep discharge. It is not current DJI recommendation.
It will not recover lost capability.

Topic 2 is not correct:  Absolutely you will get 100% and will take off with 100%.  And the automatic balance, controlled by the clever software (firmware) inside the battery, will guaranteed you that everything will be ok, even temperature.
2017-10-3
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solentlife
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BobBob .... sorry - not possible. The chemistry and physics of the batterys prevent 100% ... all you can get is very near ....

To get 100% after charge and rested - the charger would need to take the battery well over its max voltage levels of 4.35v per cell ... to allow for the drop back once rested.
The DJI board will not allow voltage to rise higher than 17.4 .... that means once disconnected and rested - pack will drop back slightly from that figure.

If you use GO to check charge level - then you are using an inacurate display as it will round up figures.

Second the balance feature on general lipo chargers works as the battery nears and reaches full charge voltage. It then discharges the high cell ... charges again to bring up low .... discharged high .... in fact cycling its actions to bring cells to balance. DJI board in no way does anything like this. In fact its pretty dumb .... it tries to balance while charging but once pack reaches total voltage - it shuts off without changing to balance function. Some say balance is done when pack is discharged - that's completely wrong.
The DJI charge system is not much more than choosing basic charge on a lipo charger .... the charger itself is only a regulated 17.4v power brick, the battery board a controller set to cut off at 17.4v total voltage of pack. The rest of the board provides the telemetry data and auto discharge functions.
Even if you use a programmable charger - you cannot balance charge - DJI board and connection prevents it.

For the balance function - it needs a change from CC to CV - plus the cyclic discharge of high cells ..... DJI charger does not have this capability.
The above is based on a group of owners testing .... not just myself - but other interested owners in different parts of the world as well.

Nigel


2017-10-3
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John Kean
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Guys can anyone help us.  I purchased a dji mavic pro platinum drone as a gift and the boys used it twice on the beach and managed to get sea water into it.  I cannot afford the repairs at €900euro and wondered if anyone knows which drone I should buy so that i can get use of the 2 spare batteries that came with it.  Can I use them on another make/model, or are they built uniquely for each drone?  Any advice from anyone would be most helpful indeed very much appreciated.
2018-7-31
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BobBob
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Flight distance : 62 ft
Peru
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RedHotPoker Posted at 2016-12-4 16:42
DJI-Tim shared this awesome info...http://forum.dji.com/thread-38174-1-1.html

How do Intelligent Batteries Work?

This is a very good article on batteries.

One missing topic here is, regarding    point 2.    Critical Low Battery Level Warning :

DURING A **FULLY AUTONOMOUS MISSION**, what will the drone do in this case, **if the Smart RTH function is turned off**.  

If the smart RTH is on, it will abort mission and will RTH immediately.  **But... if the function is off? **

It is not easy, becasue you do not know what is on the brain of the  chubby programmer of DJI.    And that is embedded in the firmware! (according to Litchi, it is encripted there).

And **WHEN** will it do it (whatever it be)?  Suppose that you are much further than 2,000 meters from home point  (DJI's firmware limit).

Will the drone continue the mission till it get the intense critical low battery level signal and will land mandatorily?

Or first, at the critical Low battery level, it will do one out of two things (following YOUR instructions defined befor take off)?   1)Will it Hover  2)Will it Land?  (Assuming that you selected one of this).   

This last paragraph is very important.
2019-3-13
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