Mavic Pro Battery Mod

[angusc]

Wow, I just read the entire thread.....took me 2.5 days on and off and ended up with only 2% remaining in the tank

Was an epic read tho.......now what about those 7000 mAh batteries, what were they called again.

 

[MacIak]

Wow, I just read the entire thread.....took me 2.5 days on and off and ended up with only 2% remaining in the tank

Was an epic read tho.......now what about those 7000 mAh batteries, what were they called again.

Well done!!
You mean these?
They S.U.C.K. , do not balance well and IR is awful.
@ everyone: still looking for an answer on the MAX RPM...what RPM equals 100% ?? Did anyone go over 10k revs? Did some searching but no luck.

 

[angusc]

So what I'm actually interested in is the standard DJI battery mods. I realised about half easy though this thread that I was reading the wrong thread! But here goes my theory......run on one battery then switch over to the backup battery and disconnect the first battery. Aren't we wasting energy of one battery charging the other with dual parallel battery setup?

 

[lolo780]

Well done!!
You mean these?
They S.U.C.K. , do not balance well and IR is awful.
@ everyone: still looking for an answer on the MAX RPM...what RPM equals 100% ?? Did anyone go over 10k revs? Did some searching but no luck.
View attachment 24932

11,200 is the most I've seen using standard props at high altitude. PMW % to RPM depends on load.

 

[Fredo]

Hi all !
I finally executed my plan for increasing my Mavic Pro flight time for cheap!
I had a Fly more pack Mavic, with 3 batteries. So why purchasing others batteries + a specific charger when you already have DJI batteries and a charger ???

I had for idea to put 2 x Original DJI Mavic Pro batteries in parallel.

For that i purchased a cheap car charger just to take the plug.:

I opened my Mavic and drilled a very small hole, just enough to pass discretly the cable. And soldered in parallel.

I just had a try with dirty scotch tape to fix the second battery on top of the first:

And believe what ??? IT WORK !!!!
It's night actually, so i just hovered 7 min in my garden. After check, both baterries was drained.
Some test results:
I can start the drone with just one battery plugged to the external cable, but DJI GO will not show any battery information (percentage, voltage, temperature, mAh remaining... etc...)
If i plug 2 batteries, Dji Go will show the first battery information.
During the flight, all looked good, percentage decreased slowly, also autonomy (in minutes) decreased.
Now next step is to test it in real flight and see if i increased my flight time.
And also find someone who will print me (in 3d) a support to fix my battery on top of the other. Like a tracker support but adapted to fit a battery.
Any 3D designer ready to help the community ? :-D

To follow.....
Thanks.
Fredo

 

[MacIak]

Hi all !
I finally executed my plan for increasing my Mavic Pro flight time for cheap!
I had a Fly more pack Mavic, with 3 batteries. So why purchasing others batteries + a specific charger when you already have DJI batteries and a charger ???

I had for idea to put 2 x Original DJI Mavic Pro batteries in parallel.

For that i purchased a cheap car charger just to take the plug.:

I opened my Mavic and drilled a very small hole, just enough to pass discretly the cable. And soldered in parallel.

I just had a try with dirty scotch tape to fix the second battery on top of the first:

And believe what ??? IT WORK !!!!
It's night actually, so i just hovered 7 min in my garden. After check, both baterries was drained.
Some test results:
I can start the drone with just one battery plugged to the external cable, but DJI GO will not show any battery information (percentage, voltage, temperature, mAh remaining... etc...)
If i plug 2 batteries, Dji Go will show the first battery information.
During the flight, all looked good, percentage decreased slowly, also autonomy (in minutes) decreased.
Now next step is to test it in real flight and see if i increased my flight time.
And also find someone who will print me (in 3d) a support to fix my battery on top of the other. Like a tracker support but adapted to fit a battery.
Any 3D designer ready to help the community ? :-D

To follow.....
Thanks.
Fredo

How about some 3m dual lock on that mount?
Or send @cruzroy a message. The mount he designed with the sides removed will do just fine.

 

[angusc]

Hi all !
I finally executed my plan for increasing my Mavic Pro flight time for cheap!
I had a Fly more pack Mavic, with 3 batteries. So why purchasing others batteries + a specific charger when you already have DJI batteries and a charger ???

I had for idea to put 2 x Original DJI Mavic Pro batteries in parallel.

For that i purchased a cheap car charger just to take the plug.:

I opened my Mavic and drilled a very small hole, just enough to pass discretly the cable. And soldered in parallel.

I just had a try with dirty scotch tape to fix the second battery on top of the first:

And believe what ??? IT WORK !!!!
It's night actually, so i just hovered 7 min in my garden. After check, both baterries was drained.
Some test results:
I can start the drone with just one battery plugged to the external cable, but DJI GO will not show any battery information (percentage, voltage, temperature, mAh remaining... etc...)
If i plug 2 batteries, Dji Go will show the first battery information.
During the flight, all looked good, percentage decreased slowly, also autonomy (in minutes) decreased.
Now next step is to test it in real flight and see if i increased my flight time.
And also find someone who will print me (in 3d) a support to fix my battery on top of the other. Like a tracker support but adapted to fit a battery.
Any 3D designer ready to help the community ? :-D

To follow.....
Thanks.
Fredo

Hi @Fredo

Your photo links are broken can you refresh them please. Just what I'm thinking but with a twist. As I have just read the entire thread, I can confirm that someone had already made such a bracket that attaches over the stock batter and then has a place for the second battery to mount in top of that. Pictures are located around the middle portion of this thread. But probably was @cruzroy as he is a 3D printer nut

 

[Fredo]

Hi @Fredo

Your photo links are broken can you refresh them please. Just what I'm thinking but with a twist. As I have just read the entire thread, I can confirm that someone had already made such a bracket that attaches over the stock batter and then has a place for the second battery to mount in top of that. Pictures are located around the middle portion of this thread. But probably was @cruzroy as he is a 3D printer nut

I changed my pictures host, is it better now?
Ok for Cruzroy, i should contact him, no time to read the 150 pages of this thread.
Thanks for infos

 

[cruzroy]

its getting close to holidays......but what do you need.........new design ????let me know i do what i can

 

[Fredo]

Hi cruzroy!
Yes I need a bracket to put a second battery on top of the first. It must be strong enough to support hard acceleration and braking. And also something that can keep the battery plug plugged on the battery.
I mean mine is plugged well and look like it will not fall during flight. But by security, I will be happy to know that the plug is keep in place by the bracket.
Do you know if this can be possible?
Thanks so much.
Fredo

 

[JustStig]

@Fredo, I'm definitely interested in your mod so please do report back!!

Here is something I remixed from various design I found.

This should work, I might have to adjust the front part to make it more aerodynamic and also notice the holder has a clip where the top battery clip into so that should make it more secure.

If it increase flight time for real I'll print one for you

 

[MacIak]

Hi cruzroy!
Yes I need a bracket to put a second battery on top of the first. It must be strong enough to support hard acceleration and braking. And also something that can keep the battery plug plugged on the battery.
I mean mine is plugged well and look like it will not fall during flight. But by security, I will be happy to know that the plug is keep in place by the bracket.
Do you know if this can be possible?
Thanks so much.
Fredo

The below is Cruzroy's design. I took away the sides but design can be easily adapted to print like this too. I hope the pics are clear.
You got a better pic of your solder job inside the mav onto the main leads? Got me confused a bit..

 

[MacIak]

Or omit the mount completely and use 3m to fix 1 battery on top of the other. Least weight too.

 

[cruzroy]

Hi cruzroy!
Yes I need a bracket to put a second battery on top of the first. It must be strong enough to support hard acceleration and braking. And also something that can keep the battery plug plugged on the battery.
I mean mine is plugged well and look like it will not fall during flight. But by security, I will be happy to know that the plug is keep in place by the bracket.
Do you know if this can be possible?
Thanks so much.
Fredo

ive been working on a dual lipo setup, and i got the bracket.......just needs finishing......im leaving today for holiday and wont be back till next Thursday.....but i need to print and test.......sorry guys.......but it will happen before Christmas

 

[cruzroy]

Hi cruzroy!
Yes I need a bracket to put a second battery on top of the first. It must be strong enough to support hard acceleration and braking. And also something that can keep the battery plug plugged on the battery.
I mean mine is plugged well and look like it will not fall during flight. But by security, I will be happy to know that the plug is keep in place by the bracket.
Do you know if this can be possible?
Thanks so much.
Fredo

more pictures

 

[cruzroy]

Hi cruzroy!
Yes I need a bracket to put a second battery on top of the first. It must be strong enough to support hard acceleration and braking. And also something that can keep the battery plug plugged on the battery.
I mean mine is plugged well and look like it will not fall during flight. But by security, I will be happy to know that the plug is keep in place by the bracket.
Do you know if this can be possible?
Thanks so much.
Fredo

 

[MacIak]

ive been working on a dual lipo setup, and i got the bracket.......just needs finishing......im leaving today for holiday and wont be back till next Thursday.....but i need to print and test.......sorry guys.......but it will happen before Christmas
View attachment 24982 View attachment 24983 View attachment 24984 View attachment 24985 View attachment 24986 View attachment 24987 View attachment 24988 View attachment 24989 View attachment 24990 View attachment 24991

Need to check how this works. It would be a clean solution for the non-extreme modders. The dji battery, even with case is lighter than the 4000mah MS lihv.
Just curious..you d need to switch on the main first and plug the ext dji batt after. Chances are likely this will cause the main to switch off as usual.

 

[JustStig]

View attachment 25002 View attachment 25003

@cruzroy , do you have the STL of that bracket you're willing to share?

Thanks

 

[Fredo]

Hi all, thanks for all your reply and your ideas.
Velcros are good idea for weight but it's not what i'm looking for as it look too ugly for me. But it's my own point of view.

I don't want to touch anything on my mavic or batteries.
I want to be able to return to an original looking Mavic, like just out of the box.
Ok i drilled a hole, but i searched an hour where to pass this cable without drilling anything and being able to close arms and to still fit in my chinese molded case. I finally found that it's impossible without drilling. But what i did is drilling under a small side cover plate. So i can remove the cable and replace the cover that none will see the hole.
I don't want to glue my batteries with such strong velcro.
That's why i'm looking for a bracket holder.

One thing for those who find my cable to small (because i know the question will finish to come... lol)
I'm electronician, i did some search and calculate the minimum cable size for this intensity.
One battery is 3.8Ah, empty in 20min, mean current is like 12A average. We will suppose some peak to 16A.
That is what must carry the cable when used with only 1 battery.
With 2 batteries, current is divided by 2, so each battery will give 8A peak.
8A is not a lot, and my 1mm² can support it. Also the current a cable can support depend of the cable length more it is and less current it can accept. Mine is like 10cm, so small !!

@JustStig : Thank you for your job, very interesting design, very close to what i have in my head. I take contact with you to discuss it.

I'm sure it will increase my flight time ! how can't it ????

Today i flew 3 times, with my 3 batteries, but once at a time. With the added cable just retained close to the body with an elastic.
All was perfectly fine ! No error, no pb.

Next step is to fly with 2 batteries connected, but i'm affraid by the idea of the top battery move and fall on the propeller because not attached properly.
But hey, we are experimenter, no ?

to follow...
Fredo

 

[cruzroy]

@cruzroy , do you have the STL of that bracket you're willing to share?

Thanks

i will after test.....but im on vacation in 2 hours.....not back for week.......but i have my mavic spark and P4 to keep me company