Using the Mavic 2 on a power supply, without a battery!

[GuNDaL]

I wanted to be able to fiddle with the settings and play with the simulator on my mavic without wasting precious battery life or wasting charge cycles on the very expensive 4S cell that DJI is using.

A bunch of googling and fiddling later.. I found other people who wanted to do the same but no answers specifically to do this, so I set out to figure it out myself.
*I am a computer engineer so I do have at least a year of schooling in electrical engineering*

Pins 3 and 4 get the negative lead and
Pins 7 and 8 get the positive lead.
If you Supply 15.2-17.4 V @ 1-2amps on a CC/CV power supply the mavic 2 will boot right up and you can do anything you want on it.. EXCEPT fly or run the motors, as the mavic is not recieving the individual voltage readouts of each cell like the dji battery would provide.

Here are some photos to show it in action!

 

[Kazzaaz]

Nice job and kudos to your tinkering. I literally bought a 3D printer with the idea of designing some sort of dual battery system but at the end of the day hardware scares me.

Check out what some of the guys on top of the range leaderboard have rigged up if you want some more inspiration:

Official Mavic 2 Range Leaderboard

In Memory of Steve William Carr. (beanbubba) THE FOLLOWING RANGE COMPETITION INFORMATION AND FORMAT IS BASED ON FEEDBACK FROM MANY FOLKS WITH A VESTED INTEREST IN THIS. I ENCOURAGE DEBATE AND OPINIONS BUT BE SURE TO CONFORM TO THE FORUM GUIDELINES. TROLLS WILL BE REPORTED. Community Rules...

mavicpilots.com

 

[brett8883]

I wanted to be able to fiddle with the settings and play with the simulator on my mavic without wasting precious battery life or wasting charge cycles on the very expensive 4S cell that DJI is using.

A bunch of googling and fiddling later.. I found other people who wanted to do the same but no answers specifically to do this, so I set out to figure it out myself.
*I am a computer engineer so I do have at least a year of schooling in electrical engineering*

Pins 3 and 4 get the negative lead and
Pins 7 and 8 get the positive lead.
If you Supply 15.2-17.4 V @ 1-2amps on a CC/CV power supply the mavic 2 will boot right up and you can do anything you want on it.. EXCEPT fly or run the motors, as the mavic is not recieving the individual voltage readouts of each cell like the dji battery would provide.

Here are some photos to show it in action!

I like it. Now you have to go for a system that lets you fly with a powered tether solution. That’s the next evolution of this idea

 

[GuNDaL]

I like it. Now you have to go for a system that lets you fly with a powered tether solution. That’s the next evolution of this idea

Haha honestly, its very doable, but I still would want the oem battery in there, in addition to the tether, so when/if it fails/gets cut/yanks out, etc. You still have a full battery to safely fly home on ?

 

[GuNDaL]

Nice job and kudos to your tinkering. I literally bought a 3D printer with the idea of designing some sort of dual battery system but at the end of the day hardware scares me.

Check out what some of the guys on top of the range leaderboard have rigged up if you want some more inspiration:

Official Mavic 2 Range Leaderboard

In Memory of Steve William Carr. (beanbubba) THE FOLLOWING RANGE COMPETITION INFORMATION AND FORMAT IS BASED ON FEEDBACK FROM MANY FOLKS WITH A VESTED INTEREST IN THIS. I ENCOURAGE DEBATE AND OPINIONS BUT BE SURE TO CONFORM TO THE FORUM GUIDELINES. TROLLS WILL BE REPORTED. Community Rules...

mavicpilots.com

Thanks! I saw some adapters that let you add additional batteries to the oem battery.

DJI Mavic 2 Pro / Zoom Battery Adapter Clip

Extend your flight time! High quality Battery Clip for increasing flight time Attaches to the Mavic 2 Pro / Zoom battery Requires one or two aux batteries (not supplied) Includes two XT60 connectors - use just one or both. If you use both, you need two 4S batteries of same capacity. Does not...

www.maxxuav.eu

 

[GadgetGuy]

Thanks! I saw some adapters that let you add additional batteries to the oem battery.

DJI Mavic 2 Pro / Zoom Battery Adapter Clip

Extend your flight time! High quality Battery Clip for increasing flight time Attaches to the Mavic 2 Pro / Zoom battery Requires one or two aux batteries (not supplied) Includes two XT60 connectors - use just one or both. If you use both, you need two 4S batteries of same capacity. Does not...

www.maxxuav.eu

I wonder if two of the clips could be adapted to use a second M2 battery mounted on top of the oem battery...

 

[brett8883]

I wonder if two of the clips could be adapted to use a second M2 battery mounted on top of the oem battery...

Better to use a dumb battery on top rather than a smart one. Cheaper and it won’t get confused thinking the first battery is trying to charge it an turn off

 

[GadgetGuy]

Better to use a dumb battery on top rather than a smart one. Cheaper and it won’t get confused thinking the first battery is trying to charge it an turn off

That was always the risk with external batteries charged to higher voltage than the internal battery. Had to bleed them off first! Certainly cheaper, but I have a bunch of older M2 batteries that are too low to use for flight (3300 mAh) but would be great as supplemental batteries. Trying to leverage that $1000 investment!

 

[GuNDaL]

That was always the risk with external batteries charged to higher voltage than the internal battery. Had to bleed them off first! Certainly cheaper, but I have a bunch of older M2 batteries that are too low to use for flight (3300 mAh) but would be great as supplemental batteries. Trying to leverage that $1000 investment!

If you have multple mavic 2 batteries that no longer hold enough charge to fly I would tear them apart, find the good cells amongst them all and rebuild as many as you can with good cells, or even recombine the cells into a "dumb battery" that can piggy back onto a good one, the other thing they could be useful for is all that circuitry to measure and report back to the mavic, maybe its possible to build an aftermarket battery that thinks like a dji intelligent battery...

I would love to attempt that.. 2 LARGE 2S batteries mounted on each side of the bird, then wired into the stock battery circuitry (with stock battery cells removed), then getting the bird to believe the external aftermarket batteries are inside the stock battery...

GadgetGuy, any chance you want to sell me an old MV2 battery that isnt fit for flight? I would absolutely attempt to come up with something! Much more inclined to rip apart a battery that can't safely be used for flight then to buy a new 200$ one just for fiddling

 

[GadgetGuy]

If you have multple mavic 2 batteries that no longer hold enough charge to fly I would tear them apart, find the good cells amongst them all and rebuild as many as you can with good cells, or even recombine the cells into a "dumb battery" that can piggy back onto a good one, the other thing they could be useful for is all that circuitry to measure and report back to the mavic, maybe its possible to build an aftermarket battery that thinks like a dji intelligent battery...

I would love to attempt that.. 2 LARGE 2S batteries mounted on each side of the bird, then wired into the stock battery circuitry (with stock battery cells removed), then getting the bird to believe the external aftermarket batteries are inside the stock battery...

GadgetGuy, any chance you want to sell me an old MV2 battery that isnt fit for flight? I would absolutely attempt to come up with something! Much more inclined to rip apart a battery that can't safely be used for flight then to buy a new 200$ one just for fiddling

I like where you are going!
When I say many of mine are too low to be used for flight at 3300 mAh, I meant for my purposes, where I need more than 22 minutes of flight time. They still work perfectly fine for 22 minute flights, but no longer offer the 24-25 minutes I get out of newer M2 batteries with 3550+ mAh. However, I would happily sell one for $120 U.S., if that isn't too much for fiddling. New, DJI still sells them for list at $159 U.S. plus tax. Shipment to Canada for Lipos may pose a problem, though.

 

[GuNDaL]

I like where you are going!
When I say many of mine are too low to be used for flight at 3300 mAh, I meant for my purposes, where I need more than 22 minutes of flight time. They still work perfectly fine for 22 minute flights, but no longer offer the 24-25 minutes I get out of newer M2 batteries with 3550+ mAh. However, I would happily sell one for $120 U.S., if that isn't too much for fiddling. New, DJI still sells them for list at $159 U.S. plus tax. Shipment to Canada for Lipos may pose a problem, though.

Ahh I misunderstood, I thought they had depleted to only giving you 5-6 min of flight time or something.
I am very new to the MV2, were the original batteries it was released with only 3300? and now they are 3850..

I think after shipping and all that they would come to just as much as a new one
I am going to try and see if I can find a used one that needs reconditioning.. I really like the idea of getting the stock circuitry to just "talk" to any battery...

Imagining a stock hollow battery that had 4 slots for 18650s that you could just land and swap real quick and keep going.. samsung INR18650-30Q x4 @ 3000mah are roughly 5$ a piece..and weigh 48grams each so 192grams ~ 20$ for a 3000mAH battery, while the DJI battery is 360g..

 

[GadgetGuy]

Ahh I misunderstood, I thought they had depleted to only giving you 5-6 min of flight time or something.
I am very new to the MV2, were the original batteries it was released with only 3300? and now they are 3850..

I think after shipping and all that they would come to just as much as a new one
I am going to try and see if I can find a used one that needs reconditioning.. I really like the idea of getting the stock circuitry to just "talk" to any battery...

Imagining a stock hollow battery that had 4 slots for 18650s that you could just land and swap real quick and keep going.. samsung INR18650-30Q x4 @ 3000mah are roughly 5$ a piece..and weigh 48grams each so 192grams ~ 20$ for a 3000mAH battery, while the DJI battery is 360g..

I am trying the new M2 Master Airscrew props that claim to add up to 1.6 minutes of flight time. That will make the depleted M2 batteries at 3300 mAh usable again for me, if the new props are for real.

M2 batteries are supposed to be 3850 mAh new. However, all new M2 batteries start out at 3700 mAh, and quickly drop to 3550 mAh within a few flights! After 30 flights they are down to 3300 mAh. DJI removed the mAh display from GO 4, hoping we wouldn't notice, but both Airdata and Litchi still display the disappointing Initial Capacity!

I'm sure there are inexpensive used M2 batteries available from those with swelling.

Eager to hear how your fiddling turns out. Keep us posted!

 

[GuNDaL]

Seriously? that sounds a lot like its software limited.. there is no way a high quality lithium battery should lose that much of its capacity from 30 discharges..

 

[GadgetGuy]

Seriously? that sounds a lot like its software limited.. there is no way a high quality lithium battery should lose that much of its capacity from 30 discharges..

More importantly, they never register even close to the advertised 3850 mAh when new!
On the P4P batteries, they start out new at 6100 mAh and are rated at 5870mAh.
By comparison, the Mavic 2 batteries need to start out new at 4000 mAh to be rated 3850 mAh. Yet they actually start out 150 mAh below 3850 mAh and end up at 3500 mAh.

We are being cheated out of 10% of the rated capacity from day one!

 

[Huo]

Excellent. Now we just need to put receiver in place of battery and track it from ground station that has gimbal with laser to send power. But how to fly upside down?

 

[GuNDaL]

Excellent. Now we just need to put receiver in place of battery and track it from ground station that has gimbal with laser to send power. But how to fly upside down?

of course! that's the next step..!

 

[GuNDaL]

More importantly, they never register even close to the advertised 3850 mAh when new!
On the P4P batteries, they start out new at 6100 mAh and are rated at 5870mAh.
By comparison, the Mavic 2 batteries need to start out new at 4000 mAh to be rated 3850 mAh. Yet they actually start out 150 mAh below 3850 mAh and end up at 3500 mAh.

We are being cheated out of 10% of the rated capacity from day one!

GadgetGuy,
are you aware of anyone who has made the mavic 2 fly off an external pack only? without piggybacking it onto an oem dji intelligent battery?

also... I think I just figured out how to get dev mode in the latest dji assistant 2.0
Mac V2.0.10
2019-10-30

 

[GadgetGuy]

GadgetGuy,
are you aware of anyone who has made the mavic 2 fly off an external pack only? without piggybacking it onto an oem dji intelligent battery?

also... I think I just figured out how to get dev mode in the latest dji assistant 2.0
Mac V2.0.10
2019-10-30

I am not, but if it has been tried or done, it's likely buried somewhere in here:

Mavic2 Battery Mods

Now that the Mavic2 is shipping, there will be great interest in all the mod possibilities. Here are some starter threads to get things kicked off: Official Mavic2 Range Leaderboard Mavic2 Battery Mods Mavic2 Battery Controller Mods Mavic2 Motor Mods Mavic2 Radio & Antenna Mods

mavicpilots.com

Happy reading!
Dev mode is definitely the place where some things can still be adjusted with the right version of Assistant 2.

 

[GuNDaL]

I am not, but if it has been tried or done, it's likely buried somewhere in here:

Mavic2 Battery Mods

Now that the Mavic2 is shipping, there will be great interest in all the mod possibilities. Here are some starter threads to get things kicked off: Official Mavic2 Range Leaderboard Mavic2 Battery Mods Mavic2 Battery Controller Mods Mavic2 Motor Mods Mavic2 Radio & Antenna Mods

mavicpilots.com

Happy reading!
Dev mode is definitely the place where some things can still be adjusted with the right version of Assistant 2.

Yea from what i've seen v1.12 was the last time dev mode was accessible.. but I just enabled it in the newest build that DJI has released.. I had to pull files from the 1.12 version and inject them into the latest version.. as not only did they comment out the code that allows you to trigger dev mode, they deleted the files that make it possible...

 

[GadgetGuy]

Yea from what i've seen v1.12 was the last time dev mode was accessible.. but I just enabled it in the newest build that DJI has released.. I had to pull files from the 1.12 version and inject them into the latest version.. as not only did they comment out the code that allows you to trigger dev mode, they deleted the files that make it possible...

Very clever of them, and you!
A tutorial of the file pulling from the 1.12 version and injection and enabling of dev mode in the newest DJI build would be very helpful!