Battery deep discharging.

[sajindra]

Hii I have a p3 standard. Today I noticed the battery capacity show 4080 mah usable. I pressed and hold the power button and noticed 3 LED bulbs are flashing. I asked from Dji and they said charge the battery to 100% and turn on the aircraft (but not motors) and discharge it to zero percent. It will take some time. Honestly, I am afraid to do this. So I decided to ask this from you.coz I learn plenty of things from this forum. Will it harmful for the battery? I am still getting 20 minutes plus flight time though. Thank you.

 

[BigAl07]

Even though it's no longer in their manual DJI does still suggest the "Deep Discharge" if you speak with them directly.

We still Deep Discharge after approx 20 charge cycles on all of our aircraft but we stop at around 8%. Just understand that pushing a LiPo down low like this is getting very near it's "point of no return" but I suspect DJI has this already built into their software as a safety precaution in their Smart Batteries.

 

[solentlife]

If you have 3 LED's flashing - then that battery is not fully charged and in fact should not have 3 LED's flashing ... only 1 LED should flash if any.

Try switching on battery first - THEN plugging in charger ........... let it fully charge up and charger automatically stop .... then check it in GO to see what it says then.

I fully discharged a battery other day as part of a test - I am definitely NOT of the deep discharge camp ! The discharge stopped at 13.62V - not the 12V as advised to me by DJI. Tech told me that battery board has a safe setting of 3V per cell cut-off ... which is basically the lowest anyone should even think of to push a lipo cell to.

As I suggest ... switch on and charge it up fully - then let us know what you get.

Nigel

 

[BigAl07]

If you have 3 LED's flashing - then that battery is not fully charged and in fact should not have 3 LED's flashing ... only 1 LED should flash if any.

Try switching on battery first - THEN plugging in charger ........... let it fully charge up and charger automatically stop .... then check it in GO to see what it says then.

I fully discharged a battery other day as part of a test - I am definitely NOT of the deep discharge camp ! The discharge stopped at 13.62V - not the 12V as advised to me by DJI. Tech told me that battery board has a safe setting of 3V per cell cut-off ... which is basically the lowest anyone should even think of to push a lipo cell to.

As I suggest ... switch on and charge it up fully - then let us know what you get.

Nigel

The OP is talking about when you check the Battery Life not the Battery Charge level of the battery.

 

[solentlife]

"Today I noticed the battery capacity show 4080 mah usable" .... that will only show when GO menu used ....

The OP is talking about when you check the Battery Life not the Battery Charge level of the battery.

"Today I noticed the battery capacity show 4080 mah usable" ....

that will only show when GO menu used ....will not tell you when checking "Battery life".

"I pressed and hold the power button and noticed 3 LED bulbs are flashing" ....

I cannot find any reference in any manual for more than one LED flashing ... which is the 12.5% incremental indicator.

Nigel

 

[sajindra]

If you have 3 LED's flashing - then that battery is not fully charged and in fact should not have 3 LED's flashing ... only 1 LED should flash if any.

Try switching on battery first - THEN plugging in charger ........... let it fully charge up and charger automatically stop .... then check it in GO to see what it says then.

I fully discharged a battery other day as part of a test - I am definitely NOT of the deep discharge camp ! The discharge stopped at 13.62V - not the 12V as advised to me by DJI. Tech told me that battery board has a safe setting of 3V per cell cut-off ... which is basically the lowest anyone should even think of to push a lipo cell to.

As I suggest ... switch on and charge it up fully - then let us know what you get.

Nigel

Actually, I did it like this, connected to The charger. When the battery's LED switched off,(fully charge), I turn off the charger ,turn on the battery and Turn on the charger again. Then battery started to charge it back. But the result is same. I pressed and hold the power button 10 seconds(checking the lifetime of the battery). As I said, 3 LEDs were flashing. App always shows the level is 4020-4100 mah.)

 

[solentlife]

First remove from charger and then check ... Charger will be creating false results.

Let me ask you to follow this :

Have battery by itself ... not connected to anything.
Switch on battery by pressing once - then press and hold second time to switch it on properly.
Now plug in charger and watch the LED's all sequencing as it charges.

Let it fully charge.

Now put into AC and check GO for the battery info. I would expect your mAh to be higher now.

The reason you switch on battery FIRST before charger - is that at high states of charge - the battery control board will not allow battery to charge. You switch on battery to over-ride that ...

What you were doing - was trying to charge with control board not over-ridden ... so it shut down and you THINK battery is full charged but its not.

Nigel

 

[sajindra]

Even though it's no longer in their manual DJI does still suggest the "Deep Discharge" if you speak with them directly.

We still Deep Discharge after approx 20 charge cycles on all of our aircraft but we stop at around 8%. Just understand that pushing a LiPo down low like this is getting very near it's "point of no return" but I suspect DJI has this already built into their software as a safety precaution in their Smart Batteries.

You mean discharge the battery 8% and charge it back. Dji suggested charge it to 100% and turn on the unit(but not motors) then let it discharge to ZERO percent. Then charge it back.i have a doubt about what Dji said. :

 

[BigAl07]

You mean discharge the battery 8% and charge it back. Dji suggested charge it to 100% and turn on the unit(but not motors) then let it discharge to ZERO percent. Then charge it back.i have a doubt about what Dji said. :

We routinely run our batteries down to 8% - 10% after approx 20 full charge cycles (as indicated in DJI Go). Depending on the intended use of the battery(back into service or into storage mode) we then charge to 100% or 50%.

For the record we fly the aircraft down to the point to where it auto lands and then continue the discharge with the aircraft on the ground.

 

[With The Birds]

We routinely run our batteries down to 8% - 10% after approx 20 full charge cycles (as indicated in DJI Go). Depending on the intended use of the battery(back into service or into storage mode) we then charge to 100% or 50%.

For the record we fly the aircraft down to the point to where it auto lands and then continue the discharge with the aircraft on the ground.

You could probably (very likely) save a lot of time and a little unnecessary wear and tear on your packs by removing this routine from your maintenance schedule. The Texas Instruments Battery management SOC’s used by DJI are well known and the features and performance documented. The charge level and remaining flight time (called “gas gauge” and “estimated time to empty” by TI) and battery life % are all determined by reference to actual cell paramaters constantly measured in use and even at open terminal voltage where self discharge rate is determined while in storage, this includes IR (TI calls this “impedance track”). There is no calibration benefit to be realised by any deep discharge routine.