Cell care?

[Von Sparkenhoffen]

Hey folks!

Does anybody know if DJI have built in over discharge cell protection in the MA2, or if the cells have it, or both?

I'm reading people reporting cell packs swelling? These folks seem to think it's due to heat? I'm of the opinion it could be down to over discharge, basically people flying the quad til the battery is in single percentage figures?

All my high powered flashlights have over discharge protection, as do some of my L ion cells, preventing damage to the cells! If DJI haven't implemented this, that's quite worrying and frankly disappointing? Li po are more delicate than L ion, and require more care...

I've seen a little cell tester for the MM, I've not seen one for the MA2 as of yet?

Cheers
V.S

 

[dawgpilot]

Yes, as described in the manual:

 

[Von Sparkenhoffen]

Paragraph 7 is worrying!

'Over discharge protection is NOT available when the battery is in use'?!!! So from reading that, I'm deducing that the battery can basically be run til it's below 3v? If this is the case, this is bad news and might possibly explain cell packs swelling? ?

 

[dawgpilot]

Paragraph 7 is worrying!

'Over discharge protection is NOT available when the battery is in use'?!!! So from reading that, I'm deducing that the battery can basically be run til it's below 3v? If this is the case, this is bad news and might possibly explain cell packs swelling? ?

It's not worrying if you think about it, because "discharge protection" while the cells are in use would mean that your drone would drop from the sky if discharge protection kicked in during that scenario. The key is to not fly the batteries down to completely empty unless you are in an emergency situation where you'd lose the drone otherwise.

 

[Von Sparkenhoffen]

It's not worrying if you think about it, because "discharge protection" while the cells are in use would mean that your drone would drop from the sky if discharge protection kicked in during that scenario. The key is to not fly the batteries down to completely empty unless you are in an emergency situation where you'd lose the drone otherwise.

So, we should all be returning to home when the battery icon turns red to prevent damage to the cell, I'm guessing. I'm going to have to find a way of accurately testing the voltage. This would explain why some of these battery packs are swelling imo, cells being run down too low, too often...

Thanks for your reply!

 

[dawgpilot]

So, we should all be returning to home when the battery icon turns red to prevent damage to the cell, I'm guessing. I'm going to have to find a way of accurately testing the voltage. This would explain why some of these battery packs are swelling imo, cells being run down too low, too often...

Thanks for your reply! ✌

My own rule of thumb is that I typically try to avoid going below 20% left on the battery while flying. I also keep my batteries charged to ~60% when I'm storing them between flying days. Don't leave them in a hot place (like a parked car in the sun), and don't leave them fully charged for extended periods of time. (I don't rely on the auto-discharge function, but will intentionally drain the batteries down to 60% either by flying the drone or by using the included USB adapter to use the drone batteries to charge my phone/tablet/etc until they are drained to the desired level)

So far I've had no issues with swelling with my original Mavic Air and it's almost 2 year old batteries, and my Mavic Air 2 batteries seem to be doing fine as well.

 

[Von Sparkenhoffen]

My own rule of thumb is that I typically try to avoid going below 20% left on the battery while flying. I also keep my batteries charged to ~60% when I'm storing them between flying days. Don't leave them in a hot place (like a parked car in the sun), and don't leave them fully charged for extended periods of time. (I don't rely on the auto-discharge function, but will intentionally drain the batteries down to 60% either by flying the drone or by using the included USB adapter to use the drone batteries to charge my phone/tablet/etc until they are drained to the desired level)

So far I've had no issues with swelling with my original Mavic Air and it's almost 2 year old batteries, and my Mavic Air 2 batteries seem to be doing fine as well.

Quality, sound advice! ?

 

[jowlymonster]

Glad I came across this post- I've only done one flight so far with my new MA2, but when I first got it, I charged all the batteries up. After my first flight (one battery down to ~22%, I recharged it ready for when I next have chance to fly...
But this suggests the batteries will discharge to help their condition. So- say I want to fly tomorrow morning at sunrise, should I re-charge the batteries again tonight? As presumably they will have discharged a bit... but then if I don't use all 3, I should manually run them down to 60% or let the automatic discharge take care of it?

 

[Von Sparkenhoffen]

Glad I came across this post- I've only done one flight so far with my new MA2, but when I first got it, I charged all the batteries up. After my first flight (one battery down to ~22%, I recharged it ready for when I next have chance to fly...
But this suggests the batteries will discharge to help their condition. So- say I want to fly tomorrow morning at sunrise, should I re-charge the batteries again tonight? As presumably they will have discharged a bit... but then if I don't use all 3, I should manually run them down to 60% or let the automatic discharge take care of it?

I would top them up if they were left for a few days or more, mine dropped to 98%, didn't take long on the charger to get back to 100%...

If you're planning on not flying for a few months, then dropping them down to 60% would be recommended. All my 18650 lithium cells were shipped at 3.2v from manufacture. I have a large collection of 18650 cells for my torches, every single one came to me at this voltage. If you're flying regular, I wouldn't be concerned with it. Just be sure not to completely drain them whilst flying! And if you are planning on not flying for months, uses dawgpilot's advice...