Mavic Pro Battery Mod

angusc · Nov 29, 2017

I have been busy making modifications to my standard Mavic pro battery, I finally managed to make up a jumper lead but when I fired up the Mavic battery switch the four Led's come on but the battery does not energise the positive lead.....I used a positive jumper lead to my battery clip and then the AC fired up and all battery readings seemed ok. I ran the AC until the fourth led went out (75%) and then stopped the AC and put the battery on charge. It looked good to start with then the charger flashed the battery lights, all went off and then the charger light went red. I'm using the stock Mavic battery charger station.

Obviously I have broken the battery controller board, but I'm just wondering if anyone else suffered a similar fate and might know the cause of this. I have attempted to use a Mavic battery as the main controller and jumped a second battery on to that one. I also connected both the main supply cables and the balanced cables in parallel mode.

lolo780 · Nov 29, 2017

angusc said:
I have been busy making modifications to my standard Maggie pro battery, I finally managed to make up a jumper lead but when I fired up the Mavic battery switch the four Led's come on but the battery does not energise the positive lead.....I used a positive jumper lead to my battery clip and then the AC fired up and all battery readings seemed ok. I ran the AC until the footrest led went out and then stored and put the battery on charge. It looked good to start with the the charger flashed the battery lights, all went off and then the charger light went red......

Obviously I have broken the battery controller board, but I'm just wondering if anyone else suffered a similar fate and might know the cause of this. I have attempted to use a Mavic battery as the main controller and jumped a second battery on to that one. I also connected both the main supply cables and the balanced cables in parallel mode.

I have one here that behaves the same way. The board was powered without seeing enough voltage and I believe it's bricked.

angusc · Nov 30, 2017

lolo780 said:
I have one here that behaves the same way. The board was powered without seeing enough voltage and I believe it's bricked.

Hi lolo780,

Do you have any idea why/how it got bricked? I had linked another battery cell to the Mavic battery main terminals (directly on to the battery cells) and ran down the battery ok. Then I used the standard Mavic charger and it recharged to full ok. I never checked the output again after that. Then I linked the individual battery cells in parallel. But while checking the balance plug terminals I did short out because my meter probes slipped.......I'm wondering if this was the cause as obviously the battery controller protects against any short circuits.......

Phxbird57 · Nov 30, 2017

Just got some new batteries in just need to switch out the ends and charge. I'll only be doing some short runs till they are broke in.

CyberNate · Nov 30, 2017

Phxbird57 said:
Just got some new batteries in just need to switch out the ends and charge. I'll only be doing some short runs till they are broke in.
View attachment 25909 View attachment 25910

Nice! Those are some good batteries. Low internal resistance. With enough weight cutting someone could run 3 of them on Mavic.

lolo780 · Nov 30, 2017

I wouldn't be surprised if they can get down around 200g uncased with lighter and shorter wires.

pilou · Nov 30, 2017

lolo780 said:
I wouldn't be surprised if they can get down around 200g uncased with lighter and shorter wires.

Uncased lithium ? Wouldn't that be a hasard in case of crash ?

Phxbird57 · Nov 30, 2017

pilou said:
Uncased lithium ? Wouldn't that be a hasard in case of crash ?

Crash who crashes around here.....

maybe a hard landing

dirtybum · Dec 1, 2017

A drone the blows up on impact, I know that's Phoenix's kind of fun right there[emoji41]

Phxbird57 · Dec 1, 2017

mubytrid said:
A drone the blows up on impact, I know that's Phoenix's kind of fun right there[emoji41]

And I have pictures

Phxbird57 · Dec 1, 2017

mubytrid said:
A drone the blows up on impact, I know that's Phoenix's kind of fun right there[emoji41]

That still is a hard landing....

koenktm · Dec 1, 2017

Planning to do my first battery mod. What is for now the best type and configuration in batteries?
The once that i see comming by here regularly:
2x multistar 4000 LIVH? Pack Multistar LiHV High Capacity 4000mAh 4S Multi-Rotor Lipo
2x Thunderpower 4500 : Thunder Power RC TP4500-3SHV

I plan to use a clip since I don't want to cut in my mavic. Any downsides in using a clip apposed to a hardwired mod?

MacIak · Dec 1, 2017

koenktm said:
Planning to do my first battery mod. What is for now the best type and configuration in batteries?
The once that i see comming by here regularly:
2x multistar 4000 LIVH? Pack Multistar LiHV High Capacity 4000mAh 4S Multi-Rotor Lipo
2x Thunderpower 4500 : Thunder Power RC TP4500-3SHV

I plan to use a clip since I don't want to cut in my mavic. Any downsides in using a clip apposed to a hardwired mod?

The MS are pretty good. Protek's sound nice too but clueless how to get these in the EU. TP gets divided opinions.
Battery clip works well. The only thing that worries me is the minimal contact surface on the pins. At times it is possible that you pull 20+ amps and im not sure if the clip can handle that in continuous mode. I ve observed slight deformation of plastic where the clip leads touch the mavic shell indicating excess heat.

lolo780 · Dec 1, 2017

koenktm said:
Planning to do my first battery mod. What is for now the best type and configuration in batteries?
The once that i see comming by here regularly:
2x multistar 4000 LIVH? Pack Multistar LiHV High Capacity 4000mAh 4S Multi-Rotor Lipo
2x Thunderpower 4500 : Thunder Power RC TP4500-3SHV

I plan to use a clip since I don't want to cut in my mavic. Any downsides in using a clip apposed to a hardwired mod?

What kind of flying do you plan to do, and which props are you using?

Phxbird57 · Dec 1, 2017

Ok after doing 2 test flights with the new Protek 3600's Guys this is a game changer. I just put one of the Protek 3600's on my Mavic ( Mavic is still stock but with the adapter to take on external batteries nothing stripped). Here are 2 test flights both only went out till about 80 or 76% and turned around. I was getting about 13000 to 14000 ft per 10% battery. I did check the Protek battery afterwards first flight to 23k the battery was at 38% the DJI Go app was showing 48% battery lift. the second flight 26k Protek battery was 28% and the DJI Go app was showing 38%. So the external batteries are draining faster that the DJI battery. I will be doing more testing. this was a quick and dirty as they say.
Airdata UAV - Flight Data Analysis for Drones

Airdata UAV - Flight Data Analysis for Drones

CyberNate · Dec 1, 2017

Phxbird57 said:
Ok after doing 2 test flights with the new Protek 3600's Guys this is a game changer. I just put one of the Protek 3600's on my Mavic ( Mavic is still stock but with the adapter to take on external batteries nothing stripped). Here are 2 test flights both only went out till about 80 or 76% and turned around. I was getting about 13000 to 14000 ft per 10% battery. I did check the Protek battery afterwards first flight to 23k the battery was at 38% the DJI Go app was showing 48% battery lift. the second flight 26k Protek battery was 28% and the DJI Go app was showing 38%. So the external batteries are draining faster that the DJI battery. I will be doing more testing. this was a quick and dirty as they say.
Airdata UAV - Flight Data Analysis for Drones

Airdata UAV - Flight Data Analysis for Drones

So that is flying with a single external battery? Have you flown with dual 3600s attached?

Yes, those batteries have low internal resistance, so they actually drain quicker than the internal battery as there is less voltage sag. The downside is that you'll have less battery on the low end. 50% reading in DJI Go is not really 50%, as the proteks will be more like 40% remaining. You'll need to turn above 60%.

Phxbird57 · Dec 1, 2017

CyberNate said:
So that is flying with a single external battery? Have you flown with dual 3600s attached?

Yes, those batteries have low internal resistance, so they actually drain quicker than the internal battery as there is less voltage sag. The downside is that you'll have less battery on the low end. 50% reading in DJI Go is not really 50%, as the proteks will be more like 40% remaining. You'll need to turn above 60%.

I have not yet tested with both externals. That will be my next testing. We have a strom front moving in. In the video i could see it coming up from the south. Probably be Monday before i get a chance to go back out.

angusc · Dec 1, 2017

lolo780 said:
I have one here that behaves the same way. The board was powered without seeing enough voltage and I believe it's bricked.

Hi @lolo780

Looking at the controller board there would appear to only be 4 likely components that could be load resistors and could in theory be "blown" if the board senses a short circuit or charging fault and wanted to stop power going out from the cells. I have access to a good board and measure a 0 ohm resistance on the two marked "R004" and a 100 ohms on the two marked "101".

Are you able to measure your bad board and let me know. I did all measurements with out de-soldering and components.

lolo780 · Dec 1, 2017

angusc said:
Hi @lolo780

Looking at the controller board there would appear to only be 4 likely components that could be load resistors and could in theory be "blown" if the board senses a short circuit or charging fault and wanted to stop power going out from the cells. I have access to a good board and measure an infinite resistance on the two marked "R004" and a 100 ohms on the two marked "101".

Are you able to measure your bad board and let me know. I did all measurements with out de-soldering and components.

I see 100 ohms on 101s and 1 ohm on R004

lolo780 · Dec 1, 2017

Phxbird57 said:
I have not yet tested with both externals. That will be my next testing. We have a strom front moving in. In the video i could see it coming up from the south. Probably be Monday before i get a chance to go back out.

Try an indoor hover test and see how many watt seconds can be put to the motors.