Mavic Pro Battery Mod

beanbubba · Mar 20, 2018

rikiki69 said:
Second part of pictures. The controller is a powerextra mavic battery controller

What's your takeoff weight?

rikiki69 · Mar 20, 2018

1200 g

chazz · Mar 20, 2018

rikiki69 said:
Second part of pictures. The controller is a powerextra mavic battery controller

Dude! this is awesome! Maybe you can help me! How do you stop the auto land using these batteries in 3s4p? I couldn't get it to stop auto land at 3.5V no matter what parameters i changed. i could fly for over 40min but half of that flight was low voltage fighting auto land and it was driving me crazy i had to give up...I went to 4s4p and now no auto land all the way to 2.5V... And whats up with that battery control board? never saw one that looks like that. Maybe you can PM the parameters you change please...

beanbubba · Mar 20, 2018

chazz said:
Dude! this is awesome! Maybe you can help me! How do you stop the auto land using these batteries in 3s4p? I couldn't get it to stop auto land at 3.5V no matter what parameters i changed. i could fly for over 40min but half of that flight was low voltage fighting auto land and it was driving me crazy i had to give up...I went to 4s4p and now no auto land all the way to 2.5V... And whats up with that battery control board? never saw one that looks like that. Maybe you can PM the parameters you change please...

I hope PM means "public message"

beanbubba · Mar 20, 2018

If we are not getting trolled again like the tanker ship moon landing or the "new" battery that had half the weight and twice the power, this appears to be a breakthrough on this topic. I will reserve judgement until everyone is in a frenzy... and then pile on for sport

beanbubba · Mar 20, 2018

zaceshighz said:
People actually believe my tanker landing post was fake? What evidence is required to clear this up? I wouldn't respond to that douche who was posting in that thread other than to troll him but getting called out by a pioneer in creating piles of wrecked Mavics like beanbubba is another matter!

You just got trolled!!! I am here until Thursday, please tip your waitresses

Please resume this thread, these are not the drones you are looking for...

chazz · Mar 21, 2018

rikiki69 said:
Hi everyone !

After having read all this thread and the factory controller mod topic, here is the result of my work. I've done this mod on a platinum
I've done a 12 cell 3s4p battery with samsung inr18650-35e and the powerextra controller mod. Average real 140wh and 700g. I've used 4.2v bms in addition to the controller in order to be able to charge the battery through the factory charger. Hovering time between 45 and 50min. But the 10 last minutes, when cell tension is below 3.15v, the mavic hasn't a lot of power, not sure it could fight wind.

To make it properly work, you have to mod the firmware and change battery voltage and disable auto landing.

I've done 3 hovering flight for the moment. Will try a 15m/s circle flight to have the max distance when the sun will be back.

Here are some picture of the fabrication, i've taken big pictures of the powerextra controller.

Everything works very well. Sometimes i get current error but it fly like a charm and the motor doesn't get really hot. But i think the low voltage at the end of the flight prevent the motors to give full power. I'm looking to find some 3.8v or 3.85v 2C cells with the same energy density (average 240wh/kg measured with the samsung cells). Original cells are announced around 220wh/kg. I'm wondering if i shouldn't dissassembled two other aftermarket battery to make a 11.4v 120wh pack (at the same weight).

How bout the airdata from these flights?

chazz · Mar 21, 2018

beanbubba said:
If we are not getting trolled again like the tanker ship moon landing or the "new" battery that had half the weight and twice the power, this appears to be a breakthrough on this topic. I will reserve judgement until everyone is in a frenzy... and then pile on for sport

I personally think the "45 to 50min" in exaggerated up a little. I tried similar things and think 40 to 45min is more likely but i can easily be proved wrong with data. I'm interested in the low voltage battery limiting thing. seems his was happening at 3.15V mine was happening at 3.5V. I think it may be related to the battery's current output. Because i changed every voltage perimeter i could find to the lowest limit with no success...

lolo780 · Mar 21, 2018

45-50min flight time is no problem if you slow down below max distance speed.

mavicpro1000 · Mar 21, 2018

Be wary of the 18650's screwing with the Mavs compass! Happened to me last week, with compass error showing in the app the Mav I suddenly had no control and smashed into the house!! Had to replace ribbon cable and all four props! Not doing that again. Anyway those cells are pretty crapp at giving out the watts we require, I'll stick to HV lipo's.

lolo780 · Mar 21, 2018

Was it messing up both compasses? Even with a compass error you should have atti mode control. Were the sticks not responding?

chazz · Mar 21, 2018

mavicpro1000 said:
Be wary of the 18650's screwing with the Mavs compass! Happened to me last week, with compass error showing in the app the Mav I suddenly had no control and smashed into the house!! Had to replace ribbon cable and all four props! Not doing that again. Anyway those cells are pretty crapp at giving out the watts we require, I'll stick to HV lipo's.

i feel for ya man. I do this stuff in a big open area when its not too windy. My compass messes up when those batteries are under it (or near it). I'll be trying some things to see if i can get around that when the weather cooperates...I know what you mean about the power thing too, lots of voltage sag here...

mavicpro1000 · Mar 21, 2018

No Atti mode kicked in. Just went and crashed while I was giving tons of stick inputs and just not responding at all. I suppose the Mav just isn't designed to carry all those metal battery casings.

JMF · Mar 21, 2018

rikiki69 said:
Second part of pictures. The controller is a powerextra mavic battery controller

LOL, how about trying a motorcycle battery ?

chazz · Mar 21, 2018

mavicpro1000 said:
No Atti mode kicked in. Just went and crashed while I was giving tons of stick inputs and just not responding at all. I suppose the Mav just isn't designed to carry all those metal battery casings.

Are you sure it wasn't responding? Things happen so fast i see how it could seem that way. Even a slight wind and the thing takes off...

chazz · Mar 21, 2018

lolo780 said:
45-50min flight time is no problem if you slow down below max distance speed.

Do you think so with this 3s battery? I made the same one with 4800's 3s3p and i got maybe 41min in hover. What do you mean by "slow down max distance speed"? Are you just saying to fly slow?

beanbubba · Mar 21, 2018

@rikiki69, Can you clarify some things for us please?

You stated: "To make it properly work, you have to mod the firmware and change battery voltage."

How exactly do you do this?

You stated: "I've taken big pictures of the powerextra controller."

Are you saying you took the guts out of the "blue" mavic 5/1 battery charger and made it part of this mod?

You have my complete and undivided attention and I am very interested to get more details of the rig you built.

Regards,
@beanbubba

lolo780 · Mar 21, 2018

chazz said:
Do you think so with this 3s battery? I made the same one with 4800's 3s3p and i got maybe 41min in hover. What do you mean by "slow down max distance speed"? Are you just saying to fly slow?

I'm using 3s LiHV and I mean there's a speed that will give maximum distance traveled and speed that will give maximum flight time.