Battery management

[I_Like_Drones]

I am a little confused as the best way to manage my batteries when I get my Mavic Pro.

I would like to keep the Mavic Pro in its bag in my car at all times so that if I find an opportune moment to fly I can just take off.

The problem is I seem to remember reading that if the batteries are left like this then there will self discharge quite quickly.

Would it be okay to then just fly within the remaining capacity of the battery, charging when done and repeating this pattern?

Another question I have is:
If I fly using a battery but it's still has plenty of juice left in it after the flight am I okay to put it back on charge until full or should I be waiting until it is less than a certain percentage before charging?

 

[msinger]

I would like to keep the Mavic Pro in its bag in my car at all times so that if I find an opportune moment to fly I can just take off.

It's okay to store batteries in your car as long as the temperature does not exceed ~82 degrees Fahrenheit. DJI recommends storing batteries in temperatures between 71-82 degrees Fahrenheit.

The problem is I seem to remember reading that if the batteries are left like this then there will self discharge quite quickly.

The batteries will start auto discharging after the set "Time to Discharge" time has been reached. That setting is stored on the battery, so you'll need to set it in DJI GO while each battery is installed in your Mavic. It'll take 2-3 days for a full battery to discharge down to the storage level after it starts to auto discharge.

Would it be okay to then just fly within the remaining capacity of the battery, charging when done and repeating this pattern?

As long as you carefully monitor the battery while you're flying and you understand how much battery power is required to make it back to the home point, then you could get away with not flying on a fully charged battery. However, it's safest to start a flight with a fully charged battery.

If I fly using a battery but it's still has plenty of juice left in it after the flight am I okay to put it back on charge until full or should I be waiting until it is less than a certain percentage before charging?

You can recharge a battery from any level.

 

[I_Like_Drones]

Thanks for that...
So a fully charged battery will stay at that charge until the 'time to discharge' target is reached and then take 2/3 days to discharge to storage capacity?

What is the maximum setting for 'time to discharge'?

 

[I_Like_Drones]

If I start flying with a battery at 70%, will it calculate the flying time and return to home time based on this value, or will it assume the flight started at 100%?

 

[msinger]

So a fully charged battery will stay at that charge until the 'time to discharge' target is reached

The batteries will deplete over time as they sit in storage, so they might drop down from a 100% charge a little if you have the time to discharge time set to 10 days and you wait ~10 days to fly. You could verify by checking your batteries after they've been sitting in storage.

What is the maximum setting for 'time to discharge'?

10 days

If I start flying with a battery at 70%, will it calculate the flying time and return to home time based on this value

Yes. Your Mavic is not smart enough to factor in the wind or other weather conditions, so you need to be mindful of that. The biggest problem you'll encounter is flying back into a headwind on a low battery.

 

[dex_]

I have a related question.

I understand it's best to store batteries at ~50%. How do most people get it to this level though, assuming after flying, your batteries are depleted to ~20%?

1. Do you start charging, and then disconnect when you see it's ~50% full?
2. Or just charge it fully, then rely on the auto-discharge function?

I assume #2 is less healthy for the battery than #1, but #1 requires "vigilance" (disconnecting the battery at the right time, while it's still charging).

 

[msinger]

I understand it's best to store batteries at ~50%. How do most people get it to this level though, assuming after flying, your batteries are depleted to ~20%?

See this post.

 

[dex_]

See this post.

Thanks msinger, that lines up with what I was thinking. I didn't know pressing the battery button resets the time to discharge counter! (Didn't see that in the manual, did you discover that on your own?)

For charging up to ~50%, instead of constantly checking the LEDs, it seems like you could compute the approximate time required to charge. For example, if depleted to 20%, you need 30% more charge, and 30% of the full ~80 minute charge cycle is ~25 minutes, so you could just set a timer for 25 minutes.

 

[I_Like_Drones]

So is there any reason NOT to leave 'time to discharge' at 10 days?
This way, my batteries would be fully charged almost anytime I want to fly...and if I don't fly for 12/13 days I will need to charge them again...

Another question...
If the batteries are left on charge I assume they will have all sorts of overcharge protection etc....but what happens after the 'time to discharge' setting is reached if they are still coneected to a charger?

 

[msinger]

Didn't see that in the manual, did you discover that on your own?

That's how all DJI batteries work. While it's not very clear in the Mavic manual, it is mentioned here:

 

[SoapyGolem]

So I have question on storing my batteries... because it's been so hot here it sucks to go stand outside since I leave in the desert.... I have all my batteries at 40to 50 percent charge put away... I haven't flown for a few weeks now... will I have to turn them on here and there ? Or will I be okay to leave them like that

 

[msinger]

I have all my batteries at 40to 50 percent charge put away... I haven't flown for a few weeks now... will I have to turn them on here and there ? Or will I be okay to leave them like that

I maintain my batteries like this when they are in storage.

 

[pbzpln]

I have mostly been just landing between 35-50% and then putting in another battery if I want to fly more, but I usually only have small windows to fly in.

As far as using a timer, I believe someone posted a chart of amps vs time, and like many batteries, they charge quicker at first, so for instance it would take less than 1/3 of the total charge time to get from 25% to 50%, so you may need to adjust a bit for this.

Pic is what I have been using to keep the batteries cool in the car, just put an ice pack or 2 in the top, I occasionally check the temp + humidity.

 

[SoapyGolem]

I maintain my batteries like this when they are in storage.

How long do you keep your batteries in storage ?

 

[msinger]

How long do you keep your batteries in storage ?

I try to use my batteries at least once every 3 months. Some have been in storage for 3+ months.

 

[SoapyGolem]

I try to use my batteries at least once every 3 months. Some have been in storage for 3+ months.

Okay thank you, just worried if I don't use them for a long time they may go bad