OK to discharge the battery to 0% ?

[BJR981S]

This test has probably been done by the others before but I haven't come across any reports yet.

Today I made my M2P hovering about 1 meter above the ground until the battery dropped to 0% and then I kept it hovering until I felt uncomfortable which is about one minute afterwards.

Upon checking the flight log ( attached ). This is what I get :

View attachment 109142

It turns out that 0% refers to the point where the battery voltage starts to drop more rapidly. In the test the drone was forced to keep hovering for 77 seconds after the battery has dropped to 0%. At the end of the flight, the battery voltage was about 3.5 volts.

I read from the internet that it is safe to discharge LiPo battery to 3V but I have to admit that I have not done a very thorough search so I am not sure whether the information is reliable. If this is true then it will be perfectly safe to discharge the battery of M2 to 0% which corresponds to about 3.6 V.

What do you guys think ?

There is much incorrect information on the net.

It is not safe to discharge a Lipo Battery to 3.0V If you read 3.0V on a Lipo after load has been removed it has discharged well below 3.0V and is permanently damaged.

You should never discharge a LiPo below 3.3V It damages the Lipo and reduces the cycle count. ny discharge below its nominal voltage is detrimental.

 

[ajkm]

Than I would recommend that you do intensive studies on batteries in general. You should also be careful with your expressions because you frequently mention 0%. What do you actually mean ? 0% voltage ? 0% capacity ? If you want to make your own decisions get your own knowledge based on facts first before you bother people with trash.

It would be good if you could reply respectfully to members of the forum. Your response is simply rude and unacceptable by any normal standards of behaviour and conversation.

 

[Manpreet Singh Bhatia]

I have done a lot of research on lipo for my office work

Lipo life, normal charge cycles are listed as 500. But if you do 50% and recharge the cycles goes 1500, if y go 25%and charge cycles go 2000. That's their life. They like being charged very often, so laotop battery survive 7 years if you or then on charge max time.
For discharge to 3.3v is where it is called safe zone. Before 3.3v cause permanent damage to cell. Partial or full

 

[Michael Ainsworth]

I accidentally forgot to turn my Nikon DSLR off, two days later discovered the totally flat battery. Would not take a charge. The only way to get it going again was to give it a few boost shocks. Did eventually recharge but only use it as an emergency backup now.

 

[Jet skier]

Yes, those things have happen from time to time, especially to pilots who do not plan before the flight.

What I am trying to understand here is whether it's safe to discharge the battery of M2 to 0%. I have repetitively heard that doing so will harm the battery but I have not seen any convincing evidence so far.

Rick from drone Valley (YouTube ) who is an electrical engineer says there’s nothing really wrong with taking it down to about zero

 

[DanMan32]

0% on DJI app is not an absolute. You can fly an M2 for as much as 2 minutes after reaching 0% before it goes down. Kyle found that out the hard way off of Long Island shore.

The P3 on the other hand shows a much lower voltage when at 0% and has little to no reserve upon reaching 0%.

Think of the % like the gas gauge on a car. Some cars still have 2 gallons after hitting E, some less.

 

[BJR981S]

I have done a lot of research on lipo for my office work

Lipo life, normal charge cycles are listed as 500. But if you do 50% and recharge the cycles goes 1500, if y go 25%and charge cycles go 2000. That's their life. They like being charged very often, so laotop battery survive 7 years if you or then on charge max time.
For discharge to 3.3v is where it is called safe zone. Before 3.3v cause permanent damage to cell. Partial or full

What you say is correct re LiPos but Laptop batteries that last many years are not LiPos they are basic LiOn with a different chemistry and don't have the same What Hour storage capability of LiPos.

 

[BJR981S]

Rick from drone Valley (YouTube ) who is an electrical engineer says there’s nothing really wrong with taking it down to about zero

Then he is a very poor electrical engineer and needs to revisit his knowledge on LiPo batteries.

 

[Rcthethird]

Yes its fine at zero, its not actually zero just safe zero. Dji would not let you damage your batteries so there is enough left in them to keep them well.

 

[Rcthethird]

Then he is a very poor electrical engineer and needs to revisit his knowledge on LiPo batteries.

Dji zero is not actual zero.

 

[BJR981S]

Yes its fine at zero, its not actually zero just safe zero. Dji would not let you damage your batteries so there is enough left in them to keep them well.

That is not correct. I think you are confusing 0V with 0%. I find that most drone flyers do not understand LiPo batteries. Those of us that fly electric helicopters and Fixed wing, Prop and EDF know full well not to discharge the LiPos below 3.7V per cell. That is about 30% remaining charge.

View any Youtube video on this subject and you will gain a better insight. Regarding DJI being philanthropic, if that was indeed the general case, then manufacturers would not build cars that can go faster than 35MPH.

 

[kidroc]

Yes, those things have happen from time to time, especially to pilots who do not plan before the flight.

What I am trying to understand here is whether it's safe to discharge the battery of M2 to 0%. I have repetitively heard that doing so will harm the battery but I have not seen any convincing evidence so far.

Not a good idea period it will cause permanent damage to your batteries land at 30% 20 if you must..

 

[Manpreet Singh Bhatia]

Not a good idea period it will cause permanent damage to your batteries land at 30% 20 if you must..

At 3.7v which is almost the end point of lipo cell. The current output On average is about 12A. But at the end of when voltage did to 3.7v. battery needs about 10-15% extra current to maintain the same performance. So theoretically hover current will be about 13 to 14 at end of usage cycle. More stress for the battery

 

[Rcthethird]

Not a good idea period it will cause permanent damage to your batteries land at 30% 20 if you must..

That is not correct. I think you are confusing 0V with 0%. I find that most drone flyers do not understand LiPo batteries. Those of us that fly electric helicopters and Fixed wing, Prop and EDF know full well not to discharge the LiPos below 3.7V per cell. That is about 30% remaining charge.

View any Youtube video on this subject and you will gain a better insight. Regarding DJI being philanthropic, if that was indeed the general case, then manufacturers would not build cars that can go faster than 35MPH.

No I think your underestimating The Dji applications. They are sold with warranty, they offer after sales warranty. I've not tested this but i'm sure the app won't let the batteries go to zero % although it says it on the app. Although the app says Zero the battery is far from it and forces the drone to land unlike an aircraft that you don't have the sophiticated app as Dji offer.
Why Would Dji be replacing batteries all the time due to avoidable and frankly dangerous lipo conditioning.
My guess, they won't.

 

[BJR981S]

No I think your underestimating The Dji applications. They are sold with warranty, they offer after sales warranty. I've not tested this but i'm sure the app won't let the batteries go to zero % although it says it on the app. Although the app says Zero the battery is far from it and forces the drone to land unlike an aircraft that you don't have the sophiticated app as Dji offer.
Why Would Dji be replacing batteries all the time due to avoidable and frankly dangerous lipo conditioning.
My guess, they won't.

You have mixed voltages up again. No. nothing bar a major catastrophe will get the Battery to 0V.

They are not Lead Acid, not NiMH, not NiCad not LiOn. They are Lipos.

LiPos have a bias Voltage of 3.0V that is they are past flat if you get them to 3.0V At 3.0V and below the chemistry is breaking down rapidly and the battery is nuked.

So The actually battery percentages is 3.3V = 0% and 4.2V =100%

The LiPo Battery chemistry is only stable at 3.7-3.8 V per cell. If you charge above this level to use the battery it actually does and consumes a Battery Charge Cycle. The further the battery is from that stable charge voltage the faster the battery deriorates. Tthis is why the Smart batteries discharge the battery down to these voltages by themselves. The same occurs when the battery is discharged below its stable voltage, the battery deteriorates.

The amount of deterioration (Active destructive chemistry) is relative to how far the current charge is away from its stable voltage level. This is exponential.

The batteries can fly perform 150 odd Cycles if you ensure you never leave the batteries fully charged and you never discharge below 30%. However if you never discharge the battery below its stable voltage 3.7V you can get 10 times the number of cycles.

Fo those that discharge to 10-20 % the life charge cycle is about 100 cycles.

This is why Battery chargers have a setting for Storage charge. LiPo Storage charge is 3.8V per Cell. This way batteries can be stored for long periods of time without damage.

The app haas nothing to do with battery discharge. You can fly the drone without the app. Its the drone that initiates RTH on low battery not the App. Thats why it can initiate the RTH on Lost Signal.

You can power up the drone without the controller or app and the drone will slowly discharge the battery below 3.0v and down to 0 and destroy the battery. Nothing Can prevent that.

The DJI App does not prevent you from doing anything Stupid, like fly illegally, fly into objects with the avoidance turned off, fly over water at too low an altitude and crash into the water.

It also does not prevent you from discharging the batteries too far. Why do you think that their drones fall from the sky if you fight the auto land on low battery. There is not enough power in the battery to keep then props spinning and the electronics powered up.

Anyhow they are your batteries, treat them as you will. Just dont come back here and say you're batteries a damaged and you want DJI to replace them under warranty.

"frankly dangerous lipo conditioning".

Are you getting confused again thinking LiPos need to be fully discharged and fully Charged i.s. Cycled / conditioned like NiCd batteries. I can assure you that is not the case. LiPos do not have a memory.

p.s. You have a misunderstanding of Warranty.

Yes DJI provide warranty for Faults in manufacture, Defects etc, not mis use of their product.

 

[Rcthethird]

I treat my batteries as you have described, stored at correct voltage and only fully charged to go out flying that day.
And i'm with you on the volts and % mate. I'm not confusing anything. Its the op that asked can or is it safe to fly to zero %, this I advised was ok as the Dji flight parameters shall we say altough saying zero % battery is in fact not Zero anything its the control app or what ever saying that this is as low as it can go. This I believe is well within you 3v per cell.

 

[BJR981S]

I treat my batteries as you have described, stored at correct voltage and only fully charged to go out flying that day.
And i'm with you on the volts and % mate. I'm not confusing anything. Its the op that asked can or is it safe to fly to zero %, this I advised was ok as the Dji flight parameters shall we say altough saying zero % battery is in fact not Zero anything its the control app or what ever saying that this is as low as it can go. This I believe is well within you 3v per cell.

Sorry My post detail was aimed at the OP.

I have cut off the part I posted re your comments for you and put it again here.

Let me know if I have misrepresented anything. It's not clear to me what was "Tongue in Cheek" (Cynical) and what not.

You can power up the drone without the controller or app and the drone will slowly discharge the battery below 3.0v and down to 0 and destroy the battery. Nothing Can prevent that.

The DJI App does not prevent you from doing anything Stupid, like fly illegally, fly into objects with the avoidance turned off, fly over water at too low an altitude and crash into the water.

It also does not prevent you from discharging the batteries too far. Why do you think that their drones fall from the sky if you fight the auto land on low battery. There is not enough power in the battery to keep then props spinning and the electronics powered up.

Anyhow they are your batteries, treat them as you will. Just dont come back here and say you're batteries a damaged and you want DJI to replace them under warranty.

"frankly dangerous lipo conditioning".

Are you getting confused again thinking LiPos need to be fully discharged and fully Charged i.s. Cycled / conditioned like NiCd batteries. I can assure you that is not the case. LiPos do not have a memory.

p.s. You have a misunderstanding of Warranty.

Yes DJI provide warranty for Faults in manufacture, Defects etc, not mis use of their product.

Cheers Brian.

p.s. My son tells me I have difficulty in recognising Cynicism. He is correct.

Another factor that I did not mention is that the % indicator in the App is not accurate. It is dependant on you follow the instructions provided by DJI.

"Every 3 months fully discharge the battery and the fully charge". This does damage the battery and does cost you a charge cycle. 1 of the 150.

What this does do it calibrates who much energy in What Hours the battery costumed in the flat to full charge.. This is then use to calibrate the % Charge.

You will see stores of people that have taken off run their batteries down to about 80% then the batteries start dropping at 1% a second till the drone crashes.

This is:

• they have continually flown their batteries down to a low charge level.
• they have not calibrated their battery with the 3 month process.

For every charge cycle, the battery loses a small percentage of its capacity. As you start getting close to the 100 Cycles that is quite a lot and can be misleading without doing the calibration.

One last elaboration the damage done can be expressed by this equation. D - Damage Done, Vr is the relative voltage from stable expressed as a modular number (no -ve) and t is the time spend at that state.

So D = VrT (2) that's T squared. Cant do superscript.

Cheers

I am very pedantic about my batteries. I have many Smart DJI batteries and many others for my Helis, Fixed Wing prop , and EDF jets.

 

[Rcthethird]

Sorry My post detail was aimed at the OP.

I have cut off the part I posted re your comments for you and put it again here.

Let me know if I have misrepresented anything. It's not clear to me what was "Tongue in Cheek" (Cynical) and what not.

You can power up the drone without the controller or app and the drone will slowly discharge the battery below 3.0v and down to 0 and destroy the battery. Nothing Can prevent that.

The DJI App does not prevent you from doing anything Stupid, like fly illegally, fly into objects with the avoidance turned off, fly over water at too low an altitude and crash into the water.

It also does not prevent you from discharging the batteries too far. Why do you think that their drones fall from the sky if you fight the auto land on low battery. There is not enough power in the battery to keep then props spinning and the electronics powered up.

Anyhow they are your batteries, treat them as you will. Just dont come back here and say you're batteries a damaged and you want DJI to replace them under warranty.

"frankly dangerous lipo conditioning".

Are you getting confused again thinking LiPos need to be fully discharged and fully Charged i.s. Cycled / conditioned like NiCd batteries. I can assure you that is not the case. LiPos do not have a memory.

p.s. You have a misunderstanding of Warranty.

Yes DJI provide warranty for Faults in manufacture, Defects etc, not mis use of their product.

Cheers Brian.

p.s. My son tells me I have difficulty in recognising Cynicism. He is correct.

Another factor that I did not mention is that the % indicator in the App is not accurate. It is dependant on you follow the instructions provided by DJI.

"Every 3 months fully discharge the battery and the fully charge". This does damage the battery and does cost you a charge cycle. 1 of the 150.

What this does do it calibrates who much energy in What Hours the battery costumed in the flat to full charge.. This is then use to calibrate the % Charge.

You will see stores of people that have taken off run their batteries down to about 80% then the batteries start dropping at 1% a second till the drone crashes.

This is:

• they have continually flown their batteries down to a low charge level.
• they have not calibrated their battery with the 3 month process.

For every charge cycle, the battery loses a small percentage of its capacity. As you start getting close to the 100 Cycles that is quite a lot and can be misleading without doing the calibration.

One last elaboration the damage done can be expressed by this equation. D - Damage Done, Vr is the relative voltage from stable expressed as a modular number (no -ve) and t is the time spend at that state.

So D = VrT (2) that's T squared. Cant do superscript.

Cheers

I am very pedantic about my batteries. I have many Smart DJI batteries and many others for my Helis, Fixed Wing prop , and EDF jets.

View attachment 110247

That's a whole lot of love needed there pal.

 

[BJR981S]

That's a whole lot of love needed there pal.

Indeed. I am retired and my whole life revolves around the Hobby I stated in my 20s. I hate to think of how many $s I spent in this Hobby.

Take care during this pandemic. It has reduced my flying hours. But I can still fly drones and helis in my Kitchen.

 

[Manpreet Singh Bhatia]

Indeed. I am retired and my whole life revolves around the Hobby I stated in my 20s. I hate to think of how many $s I spent in this Hobby.

Take care during this pandemic. It has reduced my flying hours. But I can still fly drones and helis in my Kitchen.

Wonderful to hear. I get my testosterone from a hover