Mavic Pro Battery Mod

lolo780 · Feb 24, 2018

Some interesting magnetic interference testing:

Also:

lolo780 · Feb 24, 2018

zaceshighz said:
The front left motor wires in the Mavic can be close enough to the front compass attachment point to generate compass errors. I found that out after replacing my ESC board. I'm not sure how they are routed stock cause I didn't take note before pulling it out.

Dosn't look like any effort was made at the factory to isolate them. I've also noticed some front compasses don't have sealer around the solder points. I always put silicone over the connections for strain relief, and it should also serve to keep a bit of distance from other wires.

https://d2otfaypcda2dg.cloudfront.net/blog/wp-content/uploads/2016/11/Mavic-Teardown-inside.jpg

lolo780 · Feb 24, 2018

There's the newer build Mavic with the sealed compass connections and twisted rear motor wires. Interestingly DJI ditched the heat shrink at the front compass, electing to simply run the wires into the little groove on the forward vision sensor casting.

https://www.tfix.co.uk/wp-content/u...acement-London-UK-Drone-Repair-3-1030x686.jpg

chazz · Feb 24, 2018

chazz said:
View attachment 32125 View attachment 32126

I tried a few things to stop the compass issues I’m having…I started looking into it and noticed it said compass error in the go app and the RC said “Mag Interference”. Also in the go app a warning kept coming up “Compass redundancy switch” (I think that means its switching between compass 1 and 2 IDK) so I looked at the compasses in the sensors and both of them had an error “Abnormal Compass Dire”…I bought a spare compass with the intentions of seeing if I can modify the wiring and moving the position of it but before I started that I decided to try wrapping the battery in foam and copper tape. At first when I hooked it back up the error wasn’t there and I was thinking it worked until I wrapped the Velcro zip tie to the battery to pull it tight to the Mavic then it came back. So that gave me an idea and I noticed when I pulled the battery away from the bottom of the bird the compass error would go away and when I got it closer it would come back. So ultimately putting a 5mm thick piece of foam between the bird and the battery was enough to get rid of the error. I may take all the copper tape and insulation off and add another piece of 5mm piece of foam to give it a little more distance away from the bird…

I took off all the copper tape and added another piece of 5mm foam and it seems ok. Compass 1 (the one its using) is at around 45 (whatever that means) and Compass 2 is at 150 when its in idle. when i give it throttle compass 1 goes to 100 and compass 2 goes to 250. Ive never paid attention to this but ill assume that if no error comes up its good. With this foam and a few weight loss things the bird weighs 1380 grams....I'm pretty anxious to test but it seems like rain for a while..

chazz · Feb 24, 2018

lolo780 said:
Some interesting magnetic interference testing:

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Also:

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I wonder what the plate that's under the compass is made of? The new one came with that plate too.

lolo780 · Feb 25, 2018

chazz said:
I wonder what the plate that's under the compass is made of? The new one came with that plate too.

Magnesium for light weight. I use aluminum tape to make that shield wider all around. I do know that without the Mg plate, less satellites are acquired so I figure a little more area might be good.

If you look inside a Phantom, they use a lot of metal foil inside the shell to improve sat reception.

chazz · Feb 25, 2018

zaceshighz said:
Maybe your batteries are off center in a way that is causing one set of motors to draw more current and thus throw off the compass.

Never thought of that but even before i start the motors compass 2 is a little higher. But yes good point. I like the externals favoring the front a little.

chazz · Feb 25, 2018

It was petty ugly out today like flying in a cloud but I managed to get an over 46min hover with this battery. I wasn't planing on hovering but the compass error appeared so instead of chancing losing the bird i thought id keep it close by. MAN is that one of the most boring things you can do for 46min! If i had a knife i may have stabbed myself. I think it was actually a little longer maybe another min because i landed once and air data split it into 2 flights but yeah at least 46min hover. I know a 6500rpm hover is a lot different then a 7500rpm flight but still not too bad.
http://app.airdata.com/main?share=qaYUFn...When i would face away from home id have the compass error and towards home it would go away. I think because of it fighting the wind. I ordered some of this to see if i can do anything. https://www.amazon.com/gp/product/B00H4D8GZ2/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 ...

lolo780 · Feb 25, 2018

[emoji23]

chazz · Feb 25, 2018

I was thinking the compass error was caused by a spirit so I'm thinking this should work.

mnoutdoors · Feb 25, 2018

Zeus

Memphis3 · Feb 25, 2018

chazz said:
It was petty ugly out today like flying in a cloud but I managed to get an over in a hover with this battery. I wasn't planing on hovering but the compass error appeared

.When i would face away from home id have the compass error and towards home it would go away. I think because of it fighting the wind. I ordered Magnetic shielding film MCF5 to see if i can do anything. .

Magnetic shielding film MCF5
0.0007" (0.02mm) Co69, Fe4, Mo4, Nb1, Si16, B7
Cobalt Iron Molybdenum Niobium Silicon and I do not know with B7 is

Looks Good but the above film is pretty stiff stuff and no stick.

On my DJI P3+ they had a shielding problem

DJI shielding repair was just add a larger speed tape part.

Speed tape is a soft aluminum (Al) tape used in commercial aircraft for temporary repairs. Sticks like crazy and is plastic sweep fordable. Speed tape will hold up in the rain @ 500mph winds. You can buy Speed tape in various thickness and 1" to 4" or more wide rolls. Speed tape is also use on home AC ducts so most home hardware stores sell speed tape.

To repair my DJI P3+ shielding problem per DJI repair I just used one big piece of speed tape.

Deadleg · Feb 27, 2018

chazz said:
It was petty ugly out today like flying in a cloud but I managed to get an over 46min hover with this battery. I wasn't planing on hovering but the compass error appeared so instead of chancing losing the bird i thought id keep it close by. MAN is that one of the most boring things you can do for 46min! If i had a knife i may have stabbed myself. I think it was actually a little longer maybe another min because i landed once and air data split it into 2 flights but yeah at least 46min hover. I know a 6500rpm hover is a lot different then a 7500rpm flight but still not too bad.
http://app.airdata.com/main?share=qaYUFn...When i would face away from home id have the compass error and towards home it would go away. I think because of it fighting the wind. I ordered some of this to see if i can do anything. https://www.amazon.com/gp/product/B00H4D8GZ2/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 ...

I agree it's boring . . but the data is interesting. Any chance you can post the .DAT file for that flight? Or if you prefer you could PM me. I could analyse it and send you the relevant performance graphs.

Gh0stxSinghx · Feb 27, 2018

3 x Mavic battery mod 11490mAh. Weight 633.6g.

Think not good top on mavic battery. Under the vps with battery mod but mavic pro under hot and fan air touch to battery mod?

SkyNinja · Feb 27, 2018

Gh0stxSinghx said:
3 x Mavic battery mod 11490mAh. Weight 633.6g.

Think not good top on mavic battery. Under the vps with battery mod but mavic pro under hot and fan air touch to battery mod?

Nice! Time for you to go and hit the distance limit[emoji106]

lolo780 · Feb 27, 2018

Gh0stxSinghx said:
3 x Mavic battery mod 11490mAh. Weight 633.6g.

Think not good top on mavic battery. Under the vps with battery mod but mavic pro under hot and fan air touch to battery mod?

11.5Ah plus 3.8Ah stock battery?

Under mount is better and heat into the external is actually a good thing. If your ESC temps go up you can pop the rear light cover off and the screens behind the stock vents to get airflow across the circuit boards.

Gh0stxSinghx · Feb 27, 2018

lolo780 said:
11.5Ah plus 3.8Ah stock battery?

Under mount is better and heat into the external is actually a good thing. If your ESC temps go up you can pop the rear light cover off and the screens behind the stock vents to get airflow across the circuit boards.

Thank you! Yes Stock mavic battery 3.8Ah. Show pic the screens behind the stock vents to get airflow across the circuit boards?
Or I can removed the rotors rear light cover off, wifi card and stock mavic battery cover remove weight -30g?

stock mavic battery cover remove about weight -30g.

i get dual xt60 looking prefect!

lolo780 · Feb 27, 2018

XT30 connectors would save you significant weight and space.

The screens are behind the rear vents beside the tail light.

Gh0stxSinghx · Feb 28, 2018

lolo780 said:
XT30 connectors would save you significant weight and space.

The screens are behind the rear vents beside the tail light.

Ok, I will try all XT30 make it, I don't understanding what you means is "The screens are behind the rear vents beside the tail light"

SkyNinja · Feb 28, 2018

Gh0stxSinghx said:
Ok, I will try all XT30 make it, I don't understanding what you means is "The screens are behind the rear vents beside the tail light"