We need discharge days on the Spark batteries.

What do you mean?
They discharge by themselves to 60ish%, after 10 days

Hi, thank you for bringing this query to us. We cannot set the auto-discharging time in DJI GO 4 application with the DJI Spark. The battery will start discharging automatically after being idle for ten days. Hope this helps. Thank you for your continued support!

Do you mean something similar to Mavic's batteries?

DJI Gamora Posted at 10-2 08:59
Hi, thank you for bringing this query to us. We cannot set the auto-discharging time in DJI GO 4 application with the DJI Spark. The battery will start discharging automatically after being idle for ten days. Hope this helps. Thank you for your continued support!

Are there any benefits to discharging set to 2 days over 10?  Do the batteries last longer if they have a greater charge for 10 days than 2?

ssylca44 Posted at 10-2 12:07
Do you mean something similar to Mavic's batteries?

They are all the same.

AntDX316 Posted at 10-2 12:22
Are there any benefits to discharging set to 2 days over 10?  Do the batteries last longer if they have a greater charge for 10 days than 2?

Thank you for the additional information. We don't have the option on DJI Go 4 app to change the auto-discharging time for the DJI Spark. Therefore, it is set for 10 days and we cannot change it. Hope this helps. Thank you!

AntDX316 Posted at 10-2 12:22
Are there any benefits to discharging set to 2 days over 10?  Do the batteries last longer if they have a greater charge for 10 days than 2?

Hi,

It is some kind of compromise. Lithium rechargable batteries don't like it being at full charge, that's why the battery electronics discharge the cells to 50%. On the other hand, every charge cycle counts towards the batteries death.

Cheers,
Wolferl

Wolferl Posted at 10-3 00:02
Hi,

It is some kind of compromise. Lithium rechargable batteries don't like it being at full charge, that's why the battery electronics discharge the cells to 50%. On the other hand, every charge cycle counts towards the batteries death.

3.80V is the ideal storage voltage of lipos.  At 40% the M2 showed 3.80V.

AntDX316 Posted at 10-3 00:59
3.80V is the ideal storage voltage of lipos.  At 40% the M2 showed 3.80V.

Somehow about 20%, so just over 3.7V , but not more as 3.75, would be even better:

They would not hold enough energy, in about 20 degree centigrade enviroment, to heat up to 150 degree centigrade, anymore. So no burning ;-)
Just needs a bit more checking, as every 3 month, to keep them over 3.7V.
But for a flight with an airplane, ....!

Why would you need that?