Battery Discharge < 10 days

[ddodell]

On my Mavic 1, I had the battery discharge set to 3 days ... I can't find a way to change it on the MavicPro ... it seems set at 10 days. Am I missing something obvious?

 

[msinger]

I can't find a way to change it on the MavicPro

On the Mavic 2 Pro? That setting defaults to 10 days and cannot be changed.

 

[ddodell]

On the Mavic 2 Pro? That setting defaults to 10 days and cannot be changed.

Bummer, that is what I thought ... my Mavic 1 batteries went bad after a year of use, and wanting to be more proactive with my Mavic 2 Pro batteries ... I had the Mavic 1 @ 10 days.

 

[OldBlueHeron]

Yeah, not really sure why they took that feature away. It was quite useful.

 

[Jackcutrone]

You can always just hover the drone down to the desired storage level whenever you want.

 

[Turn11]

You can always just hover the drone down to the desired storage level whenever you want.

Or short charge the battery.
Your thoughts @msinger

 

[WithTheBirds]

The DJI battery-USB power adapter is very handy. Find yourself with a full pack simply use it to power/charge your phone/tablet or other USB device.

 

[msinger]

Your thoughts @msinger

I find it's easiest to just not fully charge the batteries unless you're going to use them. If you end up not using them a few times, then just let them auto discharge down to the storage level.

 

[SteveCA]

clearly DJIs strategy is for the batteries to wear out in order to sell more batteries. If I don’t use the batteries after charging, I’ll turn in the drone and let it sit for 30 to 40 minutes to run the batteries down. 10 days is a joke

 

[DanMan32]

I disagree, but to each his own.
I hadn't had a problem at 10 days for my P3.

 

[ChipDjipro]

clearly DJIs strategy is for the batteries to wear out in order to sell more batteries. If I don’t use the batteries after charging, I’ll turn in the drone and let it sit for 30 to 40 minutes to run the batteries down. 10 days is a joke

I would never let my Drone just sit there for 30 to 40 minutes with it on. Much easier to just hover it to 50% I have always flown my Mavic pro and inspire till I reach 50% to 60% and bring it in.

 

[WithTheBirds]

I disagree, but to each his own.
I hadn't had a problem at 10 days for my P3.

You might have a problem if you extend your oil change intervals on a car outside the mileage/months specified by the manufacturer either. You will get less engine wear if you attend to it more frequently however.

It is well established that LiION chemistry ages faster when kept at high SOC for extended periods- it is fact rather than opinion.

Question is how important a consideration is it in practice.

I tend to keep two batteries fully charged in case I need to fly at short notice (I rotate those with others which are kept between 20 to 50%). I know that is going to impact the usable lifespan and performance slightly but it won’t be enough to matter. The convenience of being able to fly at short notice is a reasonable trade off for me.

 

[DanMan32]

"extended periods" is subjective.
10 days does not seem excessive to me. We usually keep our laptops charged near 100% for longer periods.

As for oil changes, vehicle wear vs harm to environment for excessive changes and drain on pocket book, I'll go by mfr intervals. Every 3k has long been found totally unnecessary with today's engine design and oil formulation, particularly with synthetic.

 

[WithTheBirds]

"extended periods" is subjective.
10 days does not seem excessive to me. We usually keep our laptops charged near 100% for longer periods.

As for oil changes, vehicle wear vs harm to environment for excessive changes and drain on pocket book, I'll go by mfr intervals. Every 3k has long been found totally unnecessary with today's engine design and oil formulation, particularly with synthetic.

Agreed- 3K (I assume you mean mikes) is an unnecessary in most circusmatances, for modern quality oils. I was also agreeing with you on the battery issue also in case you missed it. The increased life reduction won’t be an issue for most people. Number of flights and period of ownership/use will probably provide that the packs won’t fail before you upgrade.

The laptop example isn’t the best one. Simply because discharge rate in use is low. Most laptops now are .2C or lower discharge rate while in our drones we are looking at 2 or 3C. The aging effect is principally as a result of increased internal resistance. At low rates of discharge in use increased IR will often go unnoticed whereas under high load the cells will fail. That is why we don’t need auto discharge on our controllers.

As to the subjective definition of extended periods- charge after use and fly within 10 days and your time at full state of charge is pretty much always. That’s us why I rotate my packs. Keep one full forever and it might fail within 6 months, I know that from experience with dumb LiPO’s.

 

[DanMan32]

Controller discharge rate per C might not be as low as you suspect in a Mavic. Those batteries can't be that big and only last about 3 or 4 flights. So if they are only 1S, it's about matched per C to the M2 battery at 4S.

 

[mnis]

Agreed- 3K (I assume you mean mikes) is an unnecessary in most circusmatances, for modern quality oils. I was also agreeing with you on the battery issue also in case you missed it. The increased life reduction won’t be an issue for most people. Number of flights and period of ownership/use will probably provide that the packs won’t fail before you upgrade.

The laptop example isn’t the best one. Simply because discharge rate in use is low. Most laptops now are .2C or lower discharge rate while in our drones we are looking at 2 or 3C. The aging effect is principally as a result of increased internal resistance. At low rates of discharge in use increased IR will often go unnoticed whereas under high load the cells will fail. That is why we don’t need auto discharge on our controllers.

As to the subjective definition of extended periods- charge after use and fly within 10 days and your time at full state of charge is pretty much always. That’s us why I rotate my packs. Keep one full forever and it might fail within 6 months, I know that from experience with dumb LiPO’s.

And in laptops are usually lithium-ion batteries, which are not so sensitive if they are lying around for long periods fully charged. Most power banks also use lithium-ion batteries for this reason.

But lithium-polymer and high-voltage lithium-polymer batteries are very sensitive when stored at high charge levels, sometimes only a few days are enough, and there are irreversible negative changes. In any case, storage with a high level of charge leads to significantly faster aging (reduction of available total capacity).

 

[mnis]

The RC remote controls from DJI actually have an automatic discharge function for the integrated LiPo's, only the discharge happens much slower. About -1% per day battery charge is usually lost.

Here, the standby circuit, which continuously polls the power button, ensures a low but sufficient discharge rate. It is important in my opinion that always a few electrons must flow to avoid too fast battery aging. Another circuit will be integrated to prevent over-discharge.

 

[WithTheBirds]

And in laptops are usually lithium-ion batteries, which are not so sensitive if they are lying around for long periods fully charged. Most power banks also use lithium-ion batteries for this reason.

But lithium-polymer and high-voltage lithium-polymer batteries are very sensitive when stored at high charge levels, sometimes only a few days are enough, and there are irreversible negative changes. In any case, storage with a high level of charge leads to significantly faster aging (reduction of available total capacity).

LiPO is a LiION cell chemistry, it is the packaging style which differs (soft pouch vs rigid) . Yes, you can get higher C rating with most LiPO but this is largely because the pouch allows some expansion in use without problems.

The chemistry specific attributes for LiION and LiPO are shared including ageing characteristics.

Laptops and power banks use 18650 and other LiION cells as they are cheaper than LiION and the dimensions are consistent, guaranteed availability and wide choice if suppliers.

The ageing effect is partially loss of total capacity however of more relavence is the reduction in usable capacity, what you see as the remaining flight time depicted in the DJI GO app for example. This is what I was referring to in my earlier post and is simply determined by the battery ability to supply power under load.

 

[DanMan32]

The RC remote controls from DJI actually have an automatic discharge function for the integrated LiPo's, only the discharge happens much slower. About -1% per day battery charge is usually lost.

Here, the standby circuit, which continuously polls the power button, ensures a low but sufficient discharge rate. It is important in my opinion that always a few electrons must flow to avoid too fast battery aging. Another circuit will be integrated to prevent over-discharge.

The AC batteries also have a standby drain, as do laptops. If they didn't, you couldn't turn them on without external power.
Exception is when the circuit goes to hibernate which completely disconnects and you need external power (charger) to start it up.

 

[WithTheBirds]

The AC batteries also have a standby drain, as do laptops. If they didn't, you couldn't turn them on without external power.
Exception is when the circuit goes to hibernate which completely disconnects and you need external power (charger) to start it up.

Current draw of the battery management micro controller is in the uA range during standby, it is negligible in comparison to the self discharge rate of the cells. What happens with hibernation is the micro controller enters an extreme lower power state that is revived when the cells are charged to a preset minimum voltage at which point the power on function is re-enabled.