Battery voltages - full/50%/10%/auto discharge/hibernation

[inverted]

Hi all,

I could probably check for myself but it would be a lengthy process and I'm sure that someone here knows all the values
Tried searching but got too many results to check them out.

Battery full charge should be 4.20V per cell and that true for all LiPo batteries that I have/had
50% I'll check later in the evening but If someone could pitch in, you're more than welcome
I never did go to 10% so don't know the voltage
After 10 days of idle, battery does a self discharge to how many V?
After self discharge battery is good to be stored for how long?

Per manual, when drone is shut down with battery les than 10%, battery goes to hibernation to protect itself from over discharge
Is this the voltage that it's shipped in or is it shipped on higher voltage?

Any special rules/process when storing batteries for a few months?

I use LiPo batteries for a decade now and rules haven't changed much
Full - 4.20V
Low - 3.50V (usually ESC's for ordinary RC stuff issue a warning)
Lowest - 3.30V (land NOW)
RISK - 3.00V
Probable damage - <3.00V

Mavic 2 batteries because of their "intelligent" part cost about 3 times the good 4000mAh 4S LiPo battery so I'm keen on keeping them in best shape possible for as long as possible

Thanks!

 

[Kilrah]

DJI uses HV LiPos so voltages are very different.
But you should be looking at the percentage reported in the app/by the LEDs as that's what's calculated correctly.

When the battery is above it it autodischarges itself to the approptiate storage level of 60% after 10 days. They are shipped at 30% as that's what regulations now require.

These things are meant for the general public and the whole point is that people don't have to care about that.

 

[inverted]

I've been flying few days ago and landed with both batteries at around 20%
When I came home, out of curiosity which started this thread I've powered up a drone and monitored battery voltage

First I got surprised how fast does it drain battery just by sitting on a desk
All those fans inside really do eat up a battery quite fast.

Second surprise was that two different batteries reported a big difference between voltage and percentage
One reported 10% at 3.67V per cell, other at 3.72V per cell
Why such a difference?

Anyway, 0% is around 3.5V, give or take a little

There have been few reports on drones making it a fair distance even at 0%
I can think on two possible reasons:
- probably on batteries that end up on 0% but voltage is still well above 3.5V per cell
- maybe a DJI built in insurance to get your drone back by sacrificing 150$ battery but saving a 1500$ drone (won't be testing this)

3.5V per cell is well within safe operating voltage for a LiPo cell so all those posts that one should land at 30% to save your battery seem overexaggerated to me.

I'm not telling anyone to drain you battery to 10% before landing, I always try to land between 15% and 25% just as a precaution if something unpredictable happens.
I'm just trying to say that battery should be just fine if you get a bit carried away and land at 10% or a bit less

Maybe this post is just my learning curve on DJI products and it's smart features and everyone else already knows this but:
Listen to your RTH warning, it's a good feature
Pay attention regarding wind direction so you don't get strong headwind when returning home
Don't feel bad about low battery percentage, safety margin is big on DJI products