How long can MP2 batteries stay in hibernation before going bad?

lilewis · Jul 22, 2023

slup · Jul 22, 2023

Nobody knows... but if the battery was healthy when it left the production line it should be fine for a very long time with only minor degradation (say a couple years). Your biggest risk is that the battery actually was DOA when you got it without you knowing it, if you don't want to take that risk my advice is to wake it up & start to use it just before the warranty expires.

lilewis · Jul 22, 2023

slup said:
Nobody knows... but if the battery was healthy when it left the production line it should be fine for a very long time with only minor degradation (say a couple years). Your biggest risk is that the battery actually was DOA when you got it without you knowing it, if you don't want to take that risk my advice is to wake it up & start to use it just before the warranty expires.

Thanks. I have 2 batteries that haven't been used in about 1 year. Both came from DJI. I think I'll just recharge both of them and give them some exercise soon.

waynorth · Jul 22, 2023

I recently activated a new battery that was one year and two months old (the production month and year is on the box). It charged normally, and has been working perfectly fine.
If you want a more precise answer you have to ask DJI, and they won't tell you. Probably because there is no precise answer. If the battery has been stored in room temperature or colder, one and a half to two years should not be a concern.

slup · Jul 22, 2023

lilewis said:
...have 2 batteries that haven't been used in about 1 year. ...I'll just recharge both of them...

So you don't mean the factory hibernation... the state batteries are in when brand new & not yet customer charged yet & the LED's doesn't light up when button is pushed?

If that is the case & you mean that they have been previously used & placed on storage voltage (30-60%), you should definitely cycle them each 3 month & don't let them lay around unused for years.

If you have let them discharge so low that they have gone into hibernation once again (the BMS chip have turned itself off) they are likely damaged by now.

lilewis · Jul 22, 2023

slup said:
So you don't mean the factory hibernation... the state batteries are in when brand new & not yet customer charged yet & the LED's doesn't light up when button is pushed?

If that is the case & you mean that they have been previously used & placed on storage voltage (30-60%), you should definitely cycle them each 3 month & don't let them lay around unused for years.

If you have let them discharge so low that they have gone into hibernation once again (the BMS chip have turned itself off) they are likely damaged by now.

lilewis · Jul 22, 2023

Thanks for your input. They were used by me for a couple of years, then I got involved in other things. I think what I'm going to do it fully charge both batteries and test each of them by having the drone hover at about 5- 10 ft until it gives me the low battery warning. I'll time both to see if they still act like new.

slup · Jul 22, 2023

lilewis said:
...having the drone hover ... until it gives me the low battery warning. I'll time both to see if they still act like new.

Flight time is only one way to see degradation... & also the least dangerous.

What to be afraid of is instead the batteries internal resistance that builds up by use, treatment & age. If the resistance is to high the voltage drop during amp draw will be significant & can rapidly cause voltage drops down to 3,0V/cell where DJI drones initiate a forced critical low battery voltage auto landing... & this you can't stop, postpone or cancel, the drone will land no matter if it's over water or a highway full of traffic.

From hovering you should try to push the battery over safe grounds... full command forward together with full ascending during 10-30sec, repeat that several times. Then land & check the batteries for excessive heat... if they have a higher internal resistance they will feel hotter than usual.

Then take out the flightlog from your mobile device & upload it to for instance a free Airdata account. There check the battery cell voltage graphs... a new battery shouldn't drop more than 0,1-0,2V/cell during those bursts with full forward & ascending. If the battery from fully charged (4,2V/cell) already from the first burst start drop down to 3,5-3,7V/cell before it recovers it's no good at all & you will risk forced auto landings when you least expecting it... (a 0% DJI battery have 3,5V/cell... as information).

The excessive heat I mentioned above also risk to put off a sudden swelling that can dislodge the battery from the drone... from there it falls like a rock, MP2's are somewhat famous for this due to the battery & battery compartment design, with no extra room at all for a swelling battery.

lilewis · Jul 22, 2023

slup said:
Flight time is only one way to see degradation... & also the least dangerous.

What to be afraid of is instead the batteries internal resistance that builds up by use, treatment & age. If the resistance is to high the voltage drop during amp draw will be significant & can rapidly cause voltage drops down to 3,0V/cell where DJI drones initiate a forced critical low battery voltage auto landing... & this you can't stop, postpone or cancel, the drone will land no matter if it's over water or a highway full of traffic.

From hovering you should try to push the battery over safe grounds... full command forward together with full ascending during 10-30sec, repeat that several times. Then land & check the batteries for excessive heat... if they have a higher internal resistance they will feel hotter than usual.

Then take out the flightlog from your mobile device & upload it to for instance a free Airdata account. There check the battery cell voltage graphs... a new battery shouldn't drop more than 0,1-0,2V/cell during those bursts with full forward & ascending. If the battery from fully charged (4,2V/cell) already from the first burst start drop down to 3,5-3,7V/cell before it recovers it's no good at all & you will risk forced auto landings when you least expecting it... (a 0% DJI battery have 3,5V/cell... as information).

The excessive heat I mentioned above also risk to put off a sudden swelling that can dislodge the battery from the drone... from there it falls like a rock, MP2's are somewhat famous for this due to the battery & battery compartment design, with no extra room at all for a swelling battery.

Thank you Slup. Good info.

Ronny St. · Jul 30, 2023

lilewis said:
Thanks for your input. They were used by me for a couple of years, then I got involved in other things. I think what I'm going to do it fully charge both batteries and test each of them by having the drone hover at about 5- 10 ft until it gives me the low battery warning. I'll time both to see if they still act like new.

Being a M2P owner, I would be interested in the findings you got so I can test mine and make a comparison.

lilewis · Jul 31, 2023

I tested one of the batteries yesterday and it worked flawlessly. Light winds and Up/Down 250 ft, about 5 times, took half dozen photos then let the drone hover. Flew 30 min before the 25% warning came on. Didn't see any significant voltage drop.

Ronny St. · Jul 31, 2023

lilewis said:
I tested one of the batteries yesterday and it worked flawlessly. Light winds and Up/Down 250 ft, about 5 times, took half dozen photos then let the drone hover. Flew 30 min before the 25% warning came on. Didn't see any significant voltage drop.

That is very promising. I never got to 30 mins but that is due to the hovering of course, that will consume only a small amount of charge from the batteries.