Flight readiness at moment's notice.

[CDSkeeles]

Long time flyer, new A2s owner. Fly more bundle with 3 batts.

My question is with batteries and flight readiness. What are the best options when trying to keep the A2s flight ready with respect to properly maintaining the batteries while assuring there is always a full charge available.

I can think of several routines that might suffice but I would really love to read some of your methods of making sure when that spontaneous moment arrives (perfect sunrise, wildlife on the property etc..) your drone is ready to go with a healthy battery.

 

[Deleted member 103366]

My suggestion would be, follow good storage practice but be prepared to fly with a not fully charged battery and be aware that the possible flight duration will be short. The battery may behave somewhat strangely, possibly emptying more quickly than usual for a given charge level.
Consequently heights and distance should be limited, get the shot/video and land.

 

[BigAl07]

Long time flyer, new A2s owner. Fly more bundle with 3 batts.

My question is with batteries and flight readiness. What are the best options when trying to keep the A2s flight ready with respect to properly maintaining the batteries while assuring there is always a full charge available.

I can think of several routines that might suffice but I would really love to read some of your methods of making sure when that spontaneous moment arrives (perfect sunrise, wildlife on the property etc..) your drone is ready to go with a healthy battery.

You have to weigh two key components and decide how much you're willing to sacrifice to be Mission Ready 24/7.

A) Keeping a battery fully charged does add to the batterie's demise. The amount of time it's kept at 100% is key. The more batteries you have, the less time each battery is fully charged IF you have a battery rotation schedule.

B) If you get the perfect need to shoot moment how much lead time will you have? If only a matter of moments then go back to A) but if you'll have an hour or so then you should be able to charge on-the-go and bring one from 50 to full in transit.

We shoot within Emergency Services and in order to ALWAYS have one set of flight batteries at 100% we have a strict battery rotation routine while also realizing this adds wear and tear on the batteries. Every flight set (from 1 to 6 batteries depending on the aircraft) is labeled as a set. We document which set is Flight Ready (100% charge) and we rotate this throughout the inventory. We don't let any single Flight Set say at 100% for more than 7 days from the time of last charge. When a set is either flown or discharged due to hitting 7 day period, it goes back to storage level and the next Flight Set in rotation is brought to 100% and kept that way for up to 7 days.

The above procedure may be overkill in your situation but it works very well with the Depts I work with and have helped set up. It requires diligent tracking, rotating the inventory, and realizing it's putting extra wear & tear on the batteries but it works.

 

[Meta4]

My suggestion would be, follow good storage practice but be prepared to fly with a not fully charged battery and be aware that the possible flight duration will be short.

That's a bad suggestion.
Launching with a battery that's been sitting around discharging is asking for trouble and more than a few drones have been lost that way.
Only launch with a freshly charged battery.

 

[CDSkeeles]

Beyond the important considerations of limited flight time, is any harm done to the battery when stored at 50% and then flown until 25%? At that point (after cooling) should the battery be brought to 100% and then flown to 50% or charge straight to 50% in order to go back to the original flight readiness status.

Is the method in which the battery reached the 50% mark important? I have read that you should never fly an auto discharged battery until it has been fully charged again. Does this apply to a battery that was flown from 100% to 50% and then stored?

Are there time windows that I need to be aware of? For instance, is there a maximum length of time a battery should be left idle at 50% before a charge/discharge cycle? In our situation there could be a period of a month or more where the A2s would not be flown. How would larger periods of downtime effect the flight readiness regiment?

EDIT: While posting my reply I see that it has been suggested that flying with anything other than a fresh charge is not recommended. As mentioned above I read that several times in the past myself about not flying a partially discharged battery. I assume that applies to auto discharge as well as in flight discharge.

 

[CDSkeeles]

As an additional thought, I would prefer to have a battery always ready with a full charge. The thought of flying a half charged battery that had been idle for a while isn't sitting well.

My original plans were, as BigAI07 suggested, to have a rotation schedule. Of my 3 batts, one will always have a full charge but not longer than 7 days. Within that 7 days I will try to fly the battery to 50% but in the event that I cannot, the battery will discharge on its own and that time is configurable as I understand it. When the discharge event occurs (be it auto or via flight) I will then fully charge the oldest idle battery to 100% and repeat the cycle.

Of that plan, is there a performance reduction between having the battery discharge on its own versus manually during flight? I may not be able to fly weekly due to weather, work and other considerations.

 

[BigAl07]

We always prefer to FLY our batteries to the 50% mark just because otherwise it's a waste of battery and a lost opportunity. AFAIK there is no battery difference between auto-discharge and flying to storage level.

As noted, flying with a battery that is not fully charged is asking for problems. It's better to miss that golden shot than have to replace the aircraft due to judgement errors.

 

[CDSkeeles]

We always prefer to FLY our batteries to the 50% mark just because otherwise it's a waste of battery and a lost opportunity. AFAIK there is no battery difference between auto-discharge and flying to storage level.

As noted, flying with a battery that is not fully charged is asking for problems. It's better to miss that golden shot than have to replace the aircraft due to judgement errors.

Agreed and it will be my standard operating procedure.

It will be easy enough to make sure there is always one battery fully charged until it is either used or auto discharged, so long as I remember to also recharge the battery that has been discharged the longest every 7 days and move it to the drone and repeat weekly.

 

[Deleted member 103366]

My original plans were, as BigAI07 suggested, to have a rotation schedule. Of my 3 batts, one will always have a full charge but not longer than 7 days.

from p27 of the manual
"
Intelligent Flight Battery
The DJI Air 2S Intelligent Flight Battery is a 11.55 V, 3500 mAh battery with smart charging and
discharging functionality.
Battery Features
1. Battery Level Display: The LED indicators display the current battery level.
2. Auto-Discharging Function: To prevent swelling, the battery automatically discharges to 96% of the
battery level when it is idle for one day, and automatically discharges to 60% of the battery level
when it is idle for five days. It is normal to feel moderate heat being emitted from the battery during
the discharging process."

 

[Meta4]

I read that several times in the past myself about not flying a partially discharged battery. I assume that applies to auto discharge as well as in flight discharge.

It applies particularly to batteries that have been sitting for a time and auto discharging.
If you fly a battery halfway and an hour later launch again, that's no problem.
But when the battery has self-discharged, the % indicator will give a false indication of the charge level.
Analysis of flight data from this situation shows that the cell voltages are much lower than normal for the indicated % and it's common to see a battery reach critical low voltage level within a minute of launching, even though the indicated charge % showed 30% or more at launch.

 

[MAvic_South_Oz]

For sure, a half discharged battery will probably have / develop cell imbalances, and flying like that can have the double whammy of not giving a proper readout of remaining battery, and lead to faster battery degradation.

Either think of ready to fly as one hour, or, like I do with my lithium drill batteries, keep one charged and the rest waiting to charge in turn.
Every flight done like that, rotate through them charging the next in turn, numbered to ensure even use like that.

The auto discharge feature of the DJI intelligent batteries does mean to remain with one battery ready to fly, you will need to look at them every 4 days or so, wake one up by turning the battery on / off by the usual double press . . . not sure if a simple charge level 'one push' does this still ?

If not flown for a couple of weeks, you should probably let that one discharge, and charge up another in turn, continue through that process.

That will probably get pretty tiresome after a while.

 

[hiflyer201]

If you don't have four steady lites ...I think your cell phone is the next best option. It's just not worth it to risk the drone and all beneath
I've never flown without a full charge but batteries seem to be the droners dilemma. I kept my Mavic Air one charged and with me at all times in all types of temperatures, over 100 in the car, even though I never actually flew it spontaneously. The result was three DOA batteries long before their time. I luckily bough a spare battery before they became obsolete and I'm treating that one like gold.

 

[sar104]

Just having a less than fully charged battery is not a serious problem provided the cells are balanced, and you can balance the cells pretty quickly (~15 minutes) in a fast charger. That's generally what I do - keep the batteries around 60% and charge rapidly when needed.

Of course that may still be too much of a delay in some situations.