Any way to fully discharge / condition the batteries?

[AFAngryWarrior]

I've had my Air 2s for about a month now. I try to fly it daily, it relaxes me. I noticed depending on how much I actually fly around the battery never lasts more than about 20 minutes. I'm wondering if there's any way to re-condition the batteries or fully discharge them prior to their next charge. Try to see if I can get better battery life out of them.

 

[dirkclod]

With what I have always done was fly till they got low then just hover off the ground till it starts to autoland then make it stay up
i mean right off the ground till it shows 0% or just drops.
Lots disagree with that but don’t care. Works for me and been doing it since my first P2V.

 

[AFAngryWarrior]

S

With what I have always done was fly till they got low then just hover off the ground till it starts to autoland then make it stay up
i mean right off the ground till it shows 0% or just drops.
Lots disagree with that but don’t care. Works for me and been doing it since my first P2V.

Sounds reasonable. When I condition batteries for other devices it's typically by draining them first. Just wasn't sure if we could do that since around 4% it starts to auto-land. I'll have to force it to continue to hover next time.

 

[slup]

The procedure to discharge to 0% is coming from the past when the BMS chips in the batteries (Battery Management System) could go out of sync with the actual remaining battery capacity ... showing a wrong remaining battery percentage than the battery actually had, a 0% percent discharge synced these up. Today, the quality of the BMS chips are much better & these sync problems doesn't occur.

And the battery you have is a LiPo ... that will not suffer from any memory effect either ... so by doing this 0% discharge you gain nothing nowadays, you just throw away charge cycles.

Those that still follow this older advice will in general not do any harm to the battery ... a 0% DJI battery have approx. a cell voltage on 3,5V, so no harm at all ... but no gain either.

 

[StantonZ]

Those that still follow this older advice will in general not do any harm to the battery ... a 0% DJI battery have approx. a cell voltage on 3,5V, so no harm at all ... but no gain either.

...unless you leave it at that low level for anything beyond a few hours. Your other points are well-taken in that you are just "chewing up cycles".
I don't recommend discharging any Lithium-based battery beyond 20% unless it is absolutely necessary for a particular flight plan. For the record, I "practice what I preach" where my car is concerned as well (and that chemistry is more resilient than the LiPo chemistry in our drones). My 2 cents.

 

[dirkclod]

Do as you want @AFAngryWarrior i just told you what has worked for me for over 6 years and said lots would disagree. Always do.

 

[rexster1505]

The Hanatora charger will do 4 batteries at a time, charge or recondition.

 

[slup]

...unless you leave it at that low level for anything beyond a few hours...

Ha, ha Yeah, that's kind of a implied condition in that process ... but again, 0% (coming from the BMS) doesn't mean that the voltage level is damaging low, it's really close to 3,5V/cell which isn't hurting the battery a bit. All people that uses LiPo packs without a BMS chip knows that the first voltage alarm in the model (a FPV quad for instance) should be set at 3,5V/cell, the second alarm to 3,3V/cell ... this to give some headroom to get down before the battery sags below damaging 3.0V/cell. I'm using LiPo packs in my quads & always try to touch down at 3,5V/cell loaded ... once in a while it hits 3,4V/cell & those packs are perfectly fine even after 2 years use ... the capacity loss on the oldest packs comes with age & charge cycles, but the cell resistance is nearly equally good as a brand new pack.

Below is a DJI battery on 5% ... as you see, the voltage levels are a tad above 3,5V there & as soon as the battery gets unloaded & comes to rest the cells in general will recover about 0,2V when it comes to a LiPo ... so it will end up on roughly 3,7V/cell. The BMS will still report low percentages though ... the BMS recalculates when the battery gets charged.

So "a few hours" as you say is a slight overstatement ... the battery should be brought back to storage voltage within a 48h period if you want to treat it nice.

I don't recommend discharging any Lithium-based battery beyond 20% unless it is absolutely necessary...

When it comes to a battery percentage on 20% I agree, that's a good level to aim for nicely landed & motors shut off ... but not necessarily due to that going lower is damaging.

Instead 15-20% is a good safety level:
- to counter for unforeseen delays during landing
- that the voltage level tends to drop faster below those percentages
- and lastly because you on those percentages still have some headroom to deal with voltage sags so no cell momentarily drops below 3.0V where the BMS in a DJI battery initiate a "forced low battery voltage auto landing".

 

[dirkclod]

Lol

 

[MAvic_South_Oz]

0% (coming from the BMS) doesn't mean that the voltage level is damaging low, it's really close to 3,5V/cell which isn't hurting the battery a bit.

So "a few hours" as you say is a slight overstatement ... the battery should be brought back to storage voltage within a 48h period if you want to treat it nice.

A nice considered appraisal of our more modern batteries . . . think I have enough batteries to continue landing at 20% - 25% as I have since 2017 mostly, the occasional flight to 5% or 10%, but I won't be too concerned as much now if I REALLY want that extra 10 mins to finish something 'way over there'.

 

[dirkclod]

Lol

I’m sorry but I have been discharging batterys for over 6 years
every month and never had any issues. Only good results.
Do as you want and many threads on it. I chose to do mine that
way and is my choice. Do as you want but I know what works for me.

 

[MAvic_South_Oz]

As per slups post #8, both methods are probably fine.
Just charge both low and very low discharged batteries up same or next day to the 50% or so, should make no difference to longevity.
It's good to know the little tid bits picked up in @slup 's battery posts.

 

[z28lt1]

If you want to discharge your battery, easy way is after flying use the power bank adapter and then charge your controller, phone or other device form the battery.

 

[James G.]

S

Sounds reasonable. When I condition batteries for other devices it's typically by draining them first. Just wasn't sure if we could do that since around 4% it starts to auto-land. I'll have to force it to continue to hover next time.

Taking them down to just 10% is sufficient for conditioning the cells and will usually balance them also. Although I have all mine set up to self discharge after 5 days I condition all my batteries once a year by draining them down to 10% or less, wait for them to cool, then recharge back to 100%. All my batteries are all balanced and have no signs of any swelling.

 

[James G.]

Taking them down to just 10% is sufficient for conditioning the cells and will usually balance them also. Although I have all mine set up to self discharge after 5 days I condition all my batteries once a year by draining them down to 10% or less, wait for them to cool, then recharge back to 100%. All my batteries are all balanced and have no signs of any swelling.

Ha, ha Yeah, that's kind of a implied condition in that process ... but again, 0% (coming from the BMS) doesn't mean that the voltage level is damaging low, it's really close to 3,5V/cell which isn't hurting the battery a bit. All people that uses LiPo packs without a BMS chip knows that the first voltage alarm in the model (a FPV quad for instance) should be set at 3,5V/cell, the second alarm to 3,3V/cell ... this to give some headroom to get down before the battery sags below damaging 3.0V/cell. I'm using LiPo packs in my quads & always try to touch down at 3,5V/cell loaded ... once in a while it hits 3,4V/cell & those packs are perfectly fine even after 2 years use ... the capacity loss on the oldest packs comes with age & charge cycles, but the cell resistance is nearly equally good as a brand new pack.

Below is a DJI battery on 5% ... as you see, the voltage levels are a tad above 3,5V there & as soon as the battery gets unloaded & comes to rest the cells in general will recover about 0,2V when it comes to a LiPo ... so it will end up on roughly 3,7V/cell. The BMS will still report low percentages though ... the BMS recalculates when the battery gets charged.

So "a few hours" as you say is a slight overstatement ... the battery should be brought back to storage voltage within a 48h period if you want to treat it nice.
View attachment 150131


When it comes to a battery percentage on 20% I agree, that's a good level to aim for nicely landed & motors shut off ... but not necessarily due to that going lower is damaging.

Instead 15-20% is a good safety level:
- to counter for unforeseen delays during landing
- that the voltage level tends to drop faster below those percentages
- and lastly because you on those percentages still have some headroom to deal with voltage sags so no cell momentarily drops below 3.0V where the BMS in a DJI battery initiate a "forced low battery voltage auto landing".

Good info. I have read about and now use cell voltage rather than battery percentage to tell me when I should land. I never go lower than 3.6 volts regardless of what percentage is showing. Once a year I discharge all my batteries to under 10%, wait for them to cool and recharge. This re-balances cells too. I have 12 batteries in all and all are several years old and have no signs of swelling or loss of flying time.

 

[Yaros]

Don't discharge LiPos to 0%. The old days are over, when you needed to calibrate the BMS systems.
Just keep flying your batteries as you are, don't go below 10% regularly, and don't leave them charged for more than 72 hours, then they will be fine.
The charger automatically balances the cells while balancing.
I also label my batteries with numbers, and keep track of how many charge cycles I have on each of them, so I don't use always the same battery. For that I use a custom Android app I build that I'm planning to release maybe

 

[Faster]

Don't discharge LiPos to 0%. The old days are over, when you needed to calibrate the BMS systems.
Just keep flying your batteries as you are, don't go below 10% regularly, and don't leave them charged for more than 72 hours, then they will be fine.
The charger automatically balances the cells while balancing.
I also label my batteries with numbers, and keep track of how many charge cycles I have on each of them, so I don't use always the same battery. For that I use a custom Android app I build that I'm planning to release maybe

Do you know what's the cell Voltage of a DJI battery at 0%? I'm asking because it all depends on where DJI decided to put its scale from 0-100%.

 

[slup]

Do you know what's the cell Voltage of a DJI battery at 0%?...

See post #8

 

[Faster]

See post #8

That's the reason why I was asking him. I read your post since you wrote it. 0% for DJI would NEVER be the real Lipo 0% (3.0V/cell)

 

[slup]

That's the reason why I was asking him. I read your post since you wrote it. 0% for DJI would NEVER be the real Lipo 0% (3.0V/cell)

Aha ...

The chosen voltage level of 3,5V/cell to indicate 0% is a logical safety level if looking at a LiPo discharge profile ... as seen below the discharge profile suggests that 3,5V is a proper level ... after that the voltage drops rapidly, only the discharge rate shifts the drop somewhat. So if flying to 0% will most probably mean that you risk to end up on damaging low voltage levels if you encounter even the slightest delay.

3,5V/cell is as such not critical damaging, but bear in mind that the wear on the battery isn't black & white, the closer you go to either full or empty & the more often you do it ... means more wear on the battery & in the end a shorter service life.