Best battery discharge method?

[davey1der]

I’m brand new at this and would like to know the best way to discharge or drain a battery? Can I just turn it on?, or do I need to put it in my MP? Thank you.

 

[mbsz53]

Every ten flights I run my batteries all the way to zero. Keep your drone running on the ground until it drains.

 

[Former Member]

I’m brand new at this and would like to know the best way to discharge or drain a battery? Can I just turn it on?, or do I need to put it in my MP? Thank you.

I find the best way to discharge a battery is to fly it until it's down below 60%. If you cant fly it, the battery will self-discharge in a number of days according to the setting you have in DJI Go.

 

[tcope]

Just let it sit. As mentioned it will discharge down to the correct storage voltage. You don't need to discharge them down to a 0% reading at any time.

 

[Zeke]

According to the manual you should discharge each battery down to 0% at least once every 3 months to maintain battery health.

 

[davey1der]

Thank you so much for your help.

 

[davey1der]

Thanks for your help

 

[Former Member]

According to the manual you should discharge each battery down to 0% at least once every 3 months to maintain battery health.

Can you point to the page in the manual that says that? I have read the manual and cant find it.

Pages 28 - 31 give all the information you need. The lowest % that DJI mentions is on page 31 and it says to discharge to under 20% if you are taking it on a long trip.

 

[tcope]

Can you point to the page in the manual that says that? I have read the manual and cant find it.

I think as you know... it won't be found.

 

[Zeke]

It's in those little guides that came with the drone, I'm not sure if it's in the online version or not.

 

[Former Member]

It's in those little guides that came with the drone, I'm not sure if it's in the online version or not. View attachment 50090

Thank you for that. That error should really be pointed out to DJI, because the battery wont allow itself to be self-discharged to 0, and you cant fly it down to 0. The low voltage sensor in the battery and drone will force itself to land when battery level gets to 8%. Thats why many drones end up as fish bait after landing in the water, with the owner trying to return home in an unanticipated headwind.

DJI should point out that fully discharging a lipo is different than discharging it to 0. If a lipo ever gets to 0, it is officially dead, if it hasnt exploded or swelled first. Not joking. Sometimes if a lipo gets below 2.8v in any cell, it has been irreparably damaged.

Im glad you found that in the manual. There are a few other things in the manual that are ambiguous, and you have to guess what DJI means and come to your own conclusion.

 

[Kilrah]

DJI's position has evolved and that recommendation was removed from newer instructions, obviously the printed one is from back when the aircraft was released and does not include any later changes.

you cant fly it down to 0

You totally can, when it switches to "forced landing" it just shifts the zero vertical speed point to 50% stick up so all you need is hold the stick there. This summer I have been doing a cycle on my 4 Mavic batteries after several months of being unused and brought them down in flight to 3% (10cm high above grass of course) and then left the aircraft on until it turned itself off, which only took about 15 mins as a result.

The displayed % and time spent still on after landing on all 4 suggested this is indeed no more necessary.

Auto shutdown on DJI batteries is 3.2V/cell so still save damage wise. Note they're LiHV so you don't want to go as low as <3V on those.

 

[Former Member]

You totally can, when it switches to "forced landing" it just shifts the zero vertical speed point to 50% stick up so all you need is hold the stick there.

It depends what DJI considers 0.

0 to DJI might mean 3.0 volts per cell.

0 to me means 0 volts in the cell. While you might be able to fly it or idle the batteries down to DJI's "0" it's not a good idea to do it. One or more of the cells is weaker than the others, and you are risking permanent damage to the weak cell by running it that low, especially on older, many cycled batteries.

For the average owner, I recommend never flying the battery below 20%.

 

[Kilrah]

It depends what DJI considers 0.
0 to DJI might mean 3.0 volts per cell.
0 to me means 0 volts in the cell.

0 to DJI is above damage level, 3.2V/cell as I wrote above.
It's trivial to check what it is, and I'd expect someone giving advice about that to have done it instead of assuming.

 

[Bob in Savannah]

Hmmm.. So you Can discharge to 0%? Or you can't. Whatever.
Question is.. Should You?! Ugh all the disinformation about batteries these days...

 

[Former Member]

Hmmm.. So you Can discharge to 0%? Or you can't. Whatever.
Question is.. Should You?!

Simple answer. Never. (If you like your batteries)

 

[Former Member]

0 to DJI is above damage level, 3.2V/cell as I wrote above.
It's trivial to check what it is, and I'd expect someone giving advice about that to have done it instead of assuming.

It's not trivial to run your batteries below the level that can cause permanent damage or catastrophic failure. Im not going to do it, and dont recommend anyone else try.

What were your per cell voltages when you ran it to DJI's 3%? You did not mention that in your post.

 

[Kilrah]

3rd time, the battery turns itself off completely when on the ground without further warning at 3.2V/cell. 0% is typically reached a little before that depending on how well the meter is calibrated.

That's been actually criticised many times in the past becasue if you insist that much it'll crash your $1k aircraft to protect the $100 battery (which likely will be damaged in the crash so lost too anyway).

I believe it's been fixed and now knows when it's in flight and lets it go lower as a very last resort - but when that happens the battery meter has been showing 0% for quite a while already.

AKA you cannot ever be in a "damaging" battery status and have >0% displayed.

It's not trivial to run your batteries below the level that can cause permanent damage or catastrophic failure. Im not going to do it, and dont recommend anyone else try.

Just look at the battery info page?

 

[Former Member]

I would never trust the internal voltage meter in the Mavic battery when it gets to that low of a voltage. It is uncharted territory for the firmware and might relay incorrect data. It is foolish to run a battery that low while depending on the battery to report correct data. As you said, "0% is typically reached a little before that depending on how well the meter is calibrated." What if the calibration is off and the battery level is actually lower than what the battery is reporting? Disaster.

As you may or may not know, once the battery gets below a certain threshold, the battery becomes unstable, and will discharge at a rate higher than it does in mid-battery. So you are gambling that your voltage is what the battery is reporting back to the Mavic and controller, and that could be a fatal flaw.

It's trivial to check what it is, and I'd expect someone giving advice about that to have done it instead of assuming.

Better to test that on your battery and drone than on mine.

Some notes about battery usage.

• Fully charge your battery before you fly.
• If you start at less than a full charge, be aware that the second half of a battery is shorter than the first. Remember, you should land with at least 20% battery remaining.
• During your flight plan, make your first leg into the wind, and use most of your battery on that leg. Coming back with a tailwind requires less battery.
• If the winds are in excess of 10 mph, you will drain your battery faster than on a calm day. Plan for it, and plan on shorter legs of your flight.

 

[choo choo]

Hmmm.. So you Can discharge to 0%? Or you can't. Whatever.
Question is.. Should You?! Ugh all the disinformation about batteries these days...

That’s the trouble with the internet. Everybody has an opinion/theory/experience whatever.
Try Googling symptoms of say, A sore knee into a health forum and you’ll probably end up with a diagnosis ranging from bone Cancer to housemaids knee.
Do you remember the wide ranging answers to, “should I fly with gimbal guard on or off?”
They were ranging from a flat ‘no’ to ‘I do it all the time and it hasn’t affected my drone, tho it did get very hot a few times!!’ Hmm.
If I have a medical question I consult and listen to a Dr.
If I have a drone query....It’s gotta be listen to our own Dr Thunderdrones every time.