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How do Intelligent Batteries Work?
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31084 79 2015-12-28
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n5sli
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DJI-Tim Posted at 2015-12-30 10:21
There is no any method to discharge  your battery without aircraft.  
actually there is one indire ...

Has DJI considered an external charging system that would condition the battery for optimal operation? The 2-way radio industry has done this with their higher end radios. The technology is called Impres. Impres supports several different radio brands. here is a little information on it. https://www.motorolasolutions.co ... files/impres_wp.pdf
2015-12-30
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n5sli
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DJI-Tim Posted at 2015-12-30 10:21
There is no any method to discharge  your battery without aircraft.  
actually there is one indire ...

Has DJI considered an external charging system that would condition the battery for optimal operation? The 2-way radio industry has done this with their higher end radios. The technology is called Impres. Impres supports several different radio brands. here is a little information on it. [url=%5Dhttps://www.motorolasolutions.co ... mpres_wp.pdf%5B/url]]Impres batteries[/url]
2015-12-30
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DJI-Tim
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n5sli Posted at 2015-12-31 08:28
Has DJI considered an external charging system that would condition the battery for optimal operat ...

Actually this is a great idea! Thank you for suggestion
2015-12-30
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RichJ53
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Tim,

Any thoughts on my questions?  post #37

Thanks
Rich
2015-12-30
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Geebax
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n5sli Posted at 2015-12-31 11:27
Has DJI considered an external charging system that would condition the battery for optimal operat ...

The DJI intelligent battery does exactly that, all the smarts controlling the charge routine are contained in the processor inside the battery. An external charger would not add any value to the process.
2015-12-30
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Papa J
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It's an excellent PDF article thank you.  One point though you say calibrate after ten cycles?   I was always under the impression DJI advised doing this after 20 cycles and not ten?  Can you explain why this has changed please?

al
2016-1-2
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waldebus
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Good article
2016-1-2
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reggy72
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Would it be considered best practise to charge the cells inside a LiPo bag?  no matter how clever the circuitry is upon these batteries I've had serious LiPo failure before with dumb cells when I was into large scale RC cars, the LiPo bags have prevented serious injury to me and my property ( yes I use to balance charge and discharge the individual cells, but always expect the unexpected)
2016-1-2
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ezfly
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The best advice is to TURN ON

Show VOLTAGE ON MAIN SCREEN ... this will prevent  any fatal crash even if you are on latest FW.

WHY?  Because the battery % can mislead you ...

i will show you how  IF the % shows 55% and you dont see actual Voltage you can still crash your bird ..
with  Voltage ON you can see if the V is RED and has more then 3,2V

2016-1-3
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markous
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How to deep discharge???
2016-1-3
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DJI-Tim
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Keep AC on the ground, take the props off and let the motors spin till battery goes to 8%.  Then charge your battery to 100% again
2016-1-3
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DRONEFREAK55
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Great article Tim. Same concept applies to P3 batteries
2016-1-4
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DJI-Tim
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DRONEFREAK55 Posted at 2016-1-4 18:07
Great article Tim. Same concept applies to P3 batteries

Right, same about the P3 batteries! Thank you
2016-1-4
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jeffmcrae52
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DJI-Tim Posted at 2016-1-5 11:41
Right, same about the P3 batteries! Thank you

Hi Tim, when  the battery has finished charging you can then turn the battery on still hooked to the charger and the LEDs will then start flashing again does this way put more charge into the battery or help the cells to balance?
2016-1-5
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DJI-Tim
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jeffmcrae52@out Posted at 2016-1-6 11:07
Hi Tim, when  the battery has finished charging you can then turn the battery on still hooked to t ...

nope...it doesn't  help charging the battery
2016-1-5
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jeffmcrae52
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DJI-Tim Posted at 2016-1-6 14:10
nope...it doesn't  help charging the battery

Cheers Jeff
2016-1-6
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Machoman
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Live Fast Fly H Posted at 2015-12-30 19:28
So I have 6 batterys and 1 of them is tb47 the rest are tb48. How am I suppose to travel to central  ...

Remember its not allowed to put TB47 insulation stickers on your TB48
But actually its only a violation of the terms of your carrier...............
2016-1-10
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Romi
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DJI-Tim Posted at 2015-12-28 19:33
Michael! The just dischrge you r drone to the 8%. however, when its around 15% it's better put it  ...

I understand the reason WHY to perform these deep discharges every 10 cycles, but what about the health of the battery itself? Wouldn't discharging below the indicated 20% actually harm the battery's chemistry?
2016-3-21
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mattd
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Romi Posted at 2016-3-22 04:20
I understand the reason WHY to perform these deep discharges every 10 cycles, but what about the h ...

As long as it doesn't go below 3.0 volts it is fine. The battery has protection to prevent it going below a certain voltage.
2016-4-14
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diajavier
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What is the best setting in P4 for efficient battery time in a flight?
2016-4-14
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runeeriksen
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Hi Tim

I wish I read this before :-)

Today I did something that might not be that smart.
I am travelling by plane sone and somebody told me to "emty" the battery. I drained it until the Phantom 4 app told me to land because of low battery. I let it hover and kept it up even when it wanted to land by raising the left stick. It went all the way down to 0 wAH. Got a message "land or the battery might be damaged" took it down. The battery was then at 63 degrees celcius.
After it had cooled down I charged it with no problems. Got 5362 mAH and 17.2 V.
Still safe to use and to take on a airplane for summer vacation?
2016-7-4
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blackcrusader
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I have a Phantom 3 Standard and I get around 25 mins flying time if I really push to low levels to request landing.

However my battery seems fine. I have 3 batteries I use for flying.

2017-2-9
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Griffith
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DJI-Tim,  could you shed some light on the algorithm used to calculate '% Battery Remaining".  Specifically what factors are used in this determination and is it derived in the battery firmware or Mavic firmware?
2017-6-21
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Superduperwes
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So are we saying it's not possible to use a normal battery in a DJI drone?
2017-6-24
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Stryker One
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Is there any way to prevent the battery from turning itself off, or even entering "sleep" mode? I would like to set it up so that the only way to turn if off would be through the physical button on top.
2017-10-19
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djiuser_vSyY60B7zyHT
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Thanks, very helpful!
2018-8-24
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Sayhelloforme
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DJI-Tim Posted at 2016-1-3 17:24
Keep AC on the ground, take the props off and let the motors spin till battery goes to 8%.  Then charge your battery to 100% again


I thought deep discharge cycling was not required any longer    Even though I’m going to try it on one of my batteries tomorrow because cell one is a little bit lower than the other cells   Does DJI still say  we are required to discharge our batteries after 20 cycles ?
2018-8-24
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solentlife
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Please note that DJi Tim's post is way old from some years ago and contains the now obselete DJi advice about Deep Discharging.

There is NO benefit to the battery in any way whatsoever in Deep Discharging. LiPo's do NOT recover any lost capacity or capability.

BUT what happens with deep discharge here - is that you may see an increase in capacity after discharge and recharging when viewing GO's data ... but what has really happened is the Charge Controller chip on the board stuck on front of battery has had its counter re-aligned ... You have NOT recovered any mAh ... it just appears that way.

OK ... if you really do insist on discharging a DJI pack ... then eBay have various dischargers available for just a few $ ... my Telsin cost about $4 ... and it has a USB output socket so I can power / charge items from the discharged energy of the DJI pack.
There is absolutely no need to power up an AC to do this and in fact is a bad habit or practice to get into.

If you must do it ... then please have a fan or cooling air flowing over the gimbal / camera ... when updating / powered up and on the bench - I stand my P3P on a Laptop coooler ... again just a few $ ....

Nigel
2018-8-25
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Sayhelloforme
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solentlife Posted at 2018-8-25 03:20
Please note that DJi Tim's post is way old from some years ago and contains the now obselete DJi advice about Deep Discharging.

There is NO benefit to the battery in any way whatsoever in Deep Discharging. LiPo's do NOT recover any lost capacity or capability.

I thought it was old info. Thanks for your input. I’m not wanting to recover any  milliamps  But if I deep cycle the battery, will it balance the cells ? I have one battery the shows cell 1 is always off by .02. Is that “sometimes “ normal for some batteries? I was told earlier to bring it down to 5% then recharge.
2018-8-25
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solentlife
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Regardless of what you read - DJI batterys do not balance fully at any time in the charge cycle. Its a myth ...

The problem is that the charge control board works on TOTAL voltage and cuts off before balance phase can take effect. It relies on the cells following each other up in charge.

A normal charge of LiPo has three phases ...

Bulk voltage charge to get pack up to high level. (CA mode)
Diminishing amp rate to slow the charge and get maximum cell levels. (CV mode)
Balancing where high cells are 'bled off' and the charge applied to all again ... it cycles the discharge of high cells and charge of overall - till all cells are close in values.

Unfortunately DJI decided that the above was not available to us or necessary. The Charge control board tries to balance as the charge is applied ... which is possibly the worst way of attempting it. As to discharging ... there are NO lIpo's at all including DJI that balance by discharging to low level. The reason is discharge of each cell is seriously affected by Internal Resistance values. Internal Resistance fights power demand and also causes greater voltage drop on the greater resistance cells.

IMHO .. as long as you fly to 30% or so on batterys as well as short flights ... you should not need to play discharge games with batterys. Go ask any other form of RC flyer with LiPo's if he deep discharges his LiPo's ..... you will find the vast majority do not and its only those who are still to learn reality of Lipo's who do.

Nigel
2018-8-25
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RedHotPoker
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Sayhelloforme Posted at 2018-8-25 06:08
I thought it was old info. Thanks for your input. I’m not wanting to recover any  milliamps  But if I deep cycle the battery, will it balance the cells ? I have one battery the shows cell 1 is always off by .02. Is that “sometimes “ normal for some batteries? I was told earlier to bring it down to 5% then recharge.

You can try it and see if you get any change. It won’t hurt anything.

Please report back with your findings. Thanks.


RedHotPoker
2018-8-25
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Sayhelloforme
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RedHotPoker Posted at 2018-8-25 17:04
You can try it and see if you get any change. It won’t hurt anything.

Please report back with your findings. Thanks.

I did it. I ran it down to 5% the let it cool down for 2 hours recharged it and all cells are balanced.  Maybe it was a coincidence  ?  Here’s a question: I’m only getting 18  minutes of flight time  When it gets to 30% on all batteries ( I have 3 ) they have about 60 cycles on them. Is this normal ?  This  average is on any day no matter how the winds blowing or if it’s not   I never get over 18 minutes before it hits 30 %.
2018-8-25
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RedHotPoker
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Sayhelloforme Posted at 2018-8-25 18:27
I did it. I ran it down to 5% the let it cool down for 2 hours recharged it and all cells are balanced.  Maybe it was a coincidence  ?  Here’s a question: I’m only getting 18  minutes of flight time  When it gets to 30% on all batteries ( I have 3 ) they have about 60 cycles on them. Is this normal ?  This  average is on any day no matter how the winds blowing or if it’s not   I never get over 18 minutes before it hits 30 %.

Glad to hear it worked. That’s good news. All though not surprising.  ;-)

About your flight times, yes, that’s pretty average. There are a lot of variables.
The very best way to increase your flight time, is purchase another flight pack. ;-)

How’s the forum sign in going?


RedHotPoker


2018-8-25
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solentlife
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18 minutes and 30% is good.

As with all brands of any product ... the specs are always optimistic. You could get 20+ minutes if you are willing to go to very low levels of battery but if you try it - be extremely cautious of the Critical battery level ... as the battery depletes - the amps climb and voltage drop increases ... so even though you may have actually more than critical in the battery - the drop causes the software to see lower voltage and she will act on that ... It is generally not a good idea to approach critical battery levels.

As to your battery having balanced ........ as I said - the board does try balance during charge - but its not the best method ... as the battery ages - it will have harder and harder job to do it. A proper LiPo charger separates the charge sequences to enable it to fully complete each but unfortunately because DJI have hidden the balance lead inside the case - we cannot use the better system of a LiPo charger.

Nigel
2018-8-25
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Anonymous1
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In my opinion, DJI does a good job with the intelligent battery.  The auto-Return-To-Home feature does a perfect job of returning my quad to its landing spot at home with the battery perfectly at the the pre-set critical point.  I believe DJI has factored in the headroom so that each cell never gets to 3.0 Volts.  My "critical point" is set to 10%, and my warning at 30%.  Even if I ignore the 30% and keep flying further out, eventually the RTH takes over and lands me back at the original take off spot by then the battery is just about 12% and the individual cells still don't fall below the 3.6 (sometimes 3.5) Volts during the landing phase.

I've concluded that DJI designed these batteries to be abused by people with my beliefs since they left all this "reserve" in the battery capacity.  For instance, 10% capacity remaining, isn't really 10% it might be about 30% in reality, but it mentally forces us (and the craft) to land prematurely to save battery life.   I get the advertised 25 minutes manually hovering indoors (no wind) in ATTI mode (no GPS), no camera recording.
2018-8-26
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solentlife
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Anonymous1 Posted at 2018-8-26 08:21
In my opinion, DJI does a good job with the intelligent battery.  The auto-Return-To-Home feature does a perfect job of returning my quad to its landing spot at home with the battery perfectly at the the pre-set critical point.  I believe DJI has factored in the headroom so that each cell never gets to 3.0 Volts.  My "critical point" is set to 10%, and my warning at 30%.  Even if I ignore the 30% and keep flying further out, eventually the RTH takes over and lands me back at the original take off spot by then the battery is just about 12% and the individual cells still don't fall below the 3.6 (sometimes 3.5) Volts during the landing phase.

I've concluded that DJI designed these batteries to be abused by people with my beliefs since they left all this "reserve" in the battery capacity.  For instance, 10% capacity remaining, isn't really 10% it might be about 30% in reality, but it mentally forces us (and the craft) to land prematurely to save battery life.   I get the advertised 25 minutes manually hovering indoors (no wind) in ATTI mode (no GPS), no camera recording.

Yes ... DJI have created a battery that caters for the less knowledgeable LiPo user to safeguard their brand and users safety ...

It is a compromise though and an experienced LiPo user can do better - but it needs the knowledge.

I would suggest not pushing that battery Low failsafe RTH policy too often though ... one day you will have headwind going home and it will not make it ... I lost my P3S that way into the river.

Second landing with about 30% is actually a very good storage level for the LiPo ... after flight and landing at 30% .. you would expect the battery to rest and then show maybe 35% ... excellent storage level.

Nigel
2018-8-26
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Anonymous1
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If I know I'm going far, I'll set the critical to 20% for headwind
2018-8-26
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solentlife
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Anonymous1 Posted at 2018-8-26 09:09
If I know I'm going far, I'll set the critical to 20% for headwind

????

Crritical initiates auto landing ..... not RTH. Page 13 of the manual.

RTH is triggered when the App calculates remaining capacity is only sufficient to get you home ... if you do not acknowledge the warning in 10 sec's ... it starts RTH automatically. The battery capacity makes no allowance for any external effects such as headwind etc. It is best regarded as the minimum to get back in calm conditions.

The prudent operator keeps an eye on the moving power line under the menu bar ... that shows the point of RTH battery required ... and it is best policy to be going home BEFORE you reach that battery level. Critical and Low Level warning settings make no difference to that line and RTH indication other than stick red dots on it !!

Nigel
2018-8-26
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Anonymous1
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I'm just happy I've never had an issue thus far.
2018-8-26
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BobBob
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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 before take off)?   1)Will it Hover  2)Will it Land?  (Assuming that you selected one of this).   

This last paragraph is very important.

Till now nobody knows the answer  
2019-3-13
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