Mavic Pro Battery Mod

[lolo780]

I missed this mod, how/why does it work??

It puts the rear compass noise over 999 and the flight controller uses the front backup compass. A stock Mavic in sport mode or lifting extra batteries can generate enough interference to trigger a compass error. This is how people have flyaways with full GPS health.

When doing this mod, watch the compass calibration bar graphs to get the ideal position.

 

[chazz]

Hi Chaz . . I've been quietly following your progress with 18650's and with 4s setups. Glad you're pushing this along and having some success.

I am constructing a 4s2p setup, but with a slightly different design. I've cut down the battery board and arranged the batteries in a circle around the board, as per photo.

I'm wondering about the best way to connect the balance leads from a 4s battery to the Mavic battery board 3s balance pins. I presume the outer +ve and -ve balance leads have to connect directly to the outer pins (pins 1 & 4) on the balance board. That leaves a choice of 3 balance connections from the 4s battery going to the 2 internal balance connections on the board (pins 2 & 3). If I use pins 2 and 3 on the 4s I am guessing the Go 4 app will show (for 16v overall) Batt 1: 4v, Batt 2, 4v and Batt 3: 8v.

Does this sound right to you, and which balance wires did you use?

View attachment 31750

Hey Deadleg, That's great stuff!
Yeah i just go in order and from the neg side (Cell 1) and leave off the positive side (Cell 4). IDK if it matters... DJI Go shows Cell1- 4V Cell 2- 4V Cell 3- 4V and total volts 16V. Also It seems one cell (cell 1) drops faster then the others for some reason but not too bad and that's the one it shows on the main screen...Keep us updated on how things go...

 

[chazz]

You may be having compass issues due to higher motor power. Try my front compass mod and post back here. The steel knocks out the rear compass and forces the flight control to use the front.

Thanks man! Ill have to try this. I'm sure you have, but did you ever try just disconnecting the rear compass?

Edit : After looking i see its on the same board as the GPS...

 

[efowler]

Gentlemen and Ladies

May I suggest a Graphene LiPo that I use on all my birds

Advantages Graphene over traditional LiPo batteries.

• Power density: 0.15-0.17kw/kg (5Ah-16Ah)
• Power density: 0.13-0.15kw/kg (1Ah-4.9Ah).
• Stable High pack voltage through duration of use.
• High discharge rate, giving more power under load.
• Internal impedance can reach as low as 1.2mO compared to that of 3mO of a standard Lipoly.
• Greater thermal control, packs stay much cooler under extreme conditions
• Higher capacity during heavy discharge.
• Maintains higher pack capacity even after hundreds of cycles
• Fast charge capable, up to 15C on some batteries.
• Longer Cycle Life 600+

Bellow is an example but there are tons of size and 1s to 10s

Turnigy Graphene 1500mAh 6S 65C Lipo

Hi Memphis - do you have a picture of your set up with these batteries? and how much additional flight tie do they net you ?? and how much is the charger? :^)

 

[SkyNinja]

Hi Memphis - do you have a picture of your set up with these batteries? and how much additional flight tie do they net you ?? and how much is the charger? :^)

Efowler, I wouldn’t buy those batteries, they are way too heavy.

Turnigy Graphene 3000mAh 3S 65C Lipo Pack are 301g
The ProTek 3600mAh 3s 100C Graphene HV are 221g

 

[beanbubba]

It puts the rear compass noise over 999 and the flight controller uses the front backup compass. A stock Mavic in sport mode or lifting extra batteries can generate enough interference to trigger a compass error. This is how people have flyaways with full GPS health.

When doing this mod, watch the compass calibration bar graphs to get the ideal position.

So, if we add extra twists to the rear motor wires and wrap in copper foil, shouldn't this alleviate the interference? On my long range bird I would love to ditch the front compass, but I didn't know this was an option.

 

[efowler]

Efowler, I wouldn’t buy those batteries, they are way too heavy.

Turnigy Graphene 3000mAh 3S 65C Lipo Pack are 301g
The ProTek 3600mAh 3s 100C Graphene HV are 221g


View attachment 31785
View attachment 31786

Roger that SkyNinja - Thanks for the tip and the data! I am pretty set on the ProTeks. Always interested though to see all the creations people have come up with. I started my reading and education on Beanbubba's and CyberNate's and Lolo's (sorry if I left somebody out there) early on experiences and it is great to see the evolution since the early days. Very impressive - So many options - I like simplicity and following these pioneers pushing the envelop\boundaries. I am finding it hard to put this book away.

 

[Memphis3]

Graphene LiPo
Yes
I see what you mean Graphene by ProTek are light and the advantages in the air when using Graphene LiPo are better than any Std LiPo and light years better than Li Ion cells.

Critical Battery Issue
Capacity per gram weight of the battery. Graphene are a tremendous LiPo for flying machines.

 

[SkyNinja]

Roger that SkyNinja - Thanks for the tip and the data! I am pretty set on the ProTeks. Always interested though to see all the creations people have come up with. I started my reading and education on Beanbubba's and CyberNate's and Lolo's (sorry if I left somebody out there) early on experiences and it is great to see the evolution since the early days. Very impressive - So many options - I like simplicity and following these pioneers pushing the envelop\boundaries. I am finding it hard to put this book away.

There’s a lot a good guys on here with experience and that are crazy smartness. I’ve learned a lot from them. I also learned don’t be afraid to try something new. It just might work.

 

[SkyNinja]

Graphene LiPo
Yes
I see what you mean Graphene by ProTek are light and the advantages in the air when using Graphene LiPo are better than any Std LiPo and light years better than Li Ion cells.

Critical Battery Issue
Capacity per gram weight of the battery. Graphene are a tremendous LiPo for flying machines.

The majority of the people on here are not using LiPo 11.1v batteries. We are using LiHV 11.4v batteries. Which have more capacity per gram weight the most LiPo batteries.

Turnigy Graphene is a LiPo battery which is not preferred use with the Mavic due to their weight.

 

[beanbubba]

Has anyone tried Litchi to get past the limit? It will keep following your flight path when the controller disconnects from my understanding.

That is a very good point...

 

[efowler]

That is a very good point...

Another good thing about Litchi is you can tell the Mavick what speed to fly and it stays on it. In Waypoint mode (where it will stay on course even if you fly out of range of your remote) you have to set a waypoint every 6000 ft out and back. Then you can set it and watch it and if you see it is getting into trouble you can just hit the stop button and fly it manually.

 

[beanbubba]

Another good thing about Litchi is you can tell the Mavick what speed to fly and it stays on it. In Waypoint mode (where it will stay on course even if you fly out of range of your remote) you have to set a waypoint every 6000 ft out and back. Then you can set it and watch it and if you see it is getting into trouble you can just hit the stop button and fly it manually.

Can someone remind me why litchi exists in the first place??

 

[efowler]

Does anyone on this tread have any guidance on purchasing Battery chargers. i know that seems like a simple thing. I am assuming there are different types of battery chargers for different types of batteries - is that so or is there a battery charger that handles multiple types of batteries.? Any recommendations??

 

[efowler]

Can someone remind me why litchi exists in the first place??

I like it because you can program a route, speed and altitude with as many way points and points of interest that you want and launch your bird. And while it is on it mission you can be a passenger and look to the left, look to the right and look behind you and just look out the window while you bird flies its course. it is way too much fun. I know there are many more things you can do with it. If you want to do a time lapse on a building construction you can fly the same mission every day week or month and make a nice video. When it is at a way point you can program the ac to take pictures, loiter for a period of time before continuing on with the mission etc. etc. As you program your mission it tells you how much flight time it will take to complete the mission so you can make sure you dont do too many laps around the park. There are nice step by step tutorials on youtube. that is how aI learned it.There are also more complex and more capable and software packages like AutoPilot ($30). But Litchi is the simplest to learn and I got it for $13. Anyway that is my 2 cents worth.

 

[lolo780]

So, if we add extra twists to the rear motor wires and wrap in copper foil, shouldn't this alleviate the interference? On my long range bird I would love to ditch the front compass, but I didn't know this was an option.

I was still getting compass noise that would occasionally trigger an error. Could the motor itself be generating a magnetic field at high power levels?

 

[beanbubba]

Does anyone on this tread have any guidance on purchasing Battery chargers. i know that seems like a simple thing. I am assuming there are different types of battery chargers for different types of batteries - is that so or is there a battery charger that handles multiple types of batteries.? Any recommendations??

cybernate turned me on to this unit. I have 3 and they work perfect and support over packing LiHv's.

 

[beanbubba]

It's basically a clone of DJI GO. DJI has APIs that allow you to write code that interface with the RC/AC. The one feature I know of that it has that DJI GO doesn't is to create way point missions offline. In DJI GO, you have to fly to the place you want to create a way point. Litchi let's you use a google maps type interface to create way point missions.
Someone needs to try this to get passed the limit. I don't have a third battery at the moment cause I lost 2 of them in my last crash (one lost, one damaged)

So who is going to be first to set a litchi waypoint mission just past the current distance limit?? I would but weather is horrendous here.

 

[beanbubba]

I like it because you can program a route, speed and altitude with as many way points and points of interest that you want and launch your bird. And while it is on it mission you can be a passenger and look to the left, look to the right and look behind you and just look out the window while you bird flies its course. it is way too much fun. I know there are many more things you can do with it. If you want to do a time lapse on a building construction you can fly the same mission every day week or month and make a nice video. When it is at a way point you can program the ac to take pictures, loiter for a period of time before continuing on with the mission etc. etc. As you program your mission it tells you how much flight time it will take to complete the mission so you can make sure you dont do too many laps around the park. There are nice step by step tutorials on youtube. that is how aI learned it.There are also more complex and more capable and software packages like AutoPilot ($30). But Litchi is the simplest to learn and I got it for $13. Anyway that is my 2 cents worth.

Very cool, I did not know that. Thx for sharing.

 

[chazz]

I was still getting compass noise that would occasionally trigger an error. Could the motor itself be generating a magnetic field at high power levels?

My compass issues seem to happen when the batteries are under or close to under the compass and if I adjust the batteries forward it goes away. I’ve used the same batteries in a few different configurations and I always get the compass error when it’s under the compass. This time the batteries pretty long and I can’t move it forward enough. The pic with the black battery I get the error and the red one I don’t and they’re both 4 cells. I may try the washer trick but i was also thinking of extending the wires and moving the compass somewhere else. I don't know much about the compass or GPS unit i wonder if the orientation matters? I don't even know where id move it to yet.

.