Mavic Pro Battery Mod

angusc · Dec 18, 2017

Blnkstefaans said:
Will this work, without getting an error?

Will this charge with the normal mavic charger?

Yes works without any error messages..
Yes will charge from standard Mavic charger providing you don't damage the battery controller board.

For your suggested arrangement you could drill in to the top of the bottom battery and then solder on the second battery cells to the main battery board. Or are you thinking to make a completely new assembly inside your printed case/housing?

I'm still in testing mode with my setup and don't yet have solid flight data as it's been cold and windy here in UK for a few weeks now.

mlash · Dec 18, 2017

Phxbird57 said:
I'm doing a full charge but only flying them down to 40%. for the first few times. Dirtbum said that Protek ask you to do a break in for the first few times like 5 at 50%.

Sounds good thanks for the info.

Savixor · Dec 18, 2017

lolo780 said:
Switch to non DJI battery in assistant, and turn the voltage thresholds down to minimum, as well as LED warning only.

This means that I won't have smart RTH right? My controller wont beep at critical battery too right?

lolo780 · Dec 18, 2017

Savixor said:
This means that I won't have smart RTH right? My controller wont beep at critical battery too right?

RTH will work as you set it. Autoland will kick in, but later than normal. Depending on the voltage curve of your externals, that can mean land ASAP, or keep going. For my Thunderpower batteries, even when it gives a critical voltage landing message I can still go another few minutes and the loss of power is very gradual.

Blnkstefaans · Dec 19, 2017

angusc said:
Yes works without any error messages..
Yes will charge from standard Mavic charger providing you don't damage the battery controller board.

For your suggested arrangement you could drill in to the top of the bottom battery and then solder on the second battery cells to the main battery board. Or are you thinking to make a completely new assembly inside your printed case/housing?

I'm still in testing mode with my setup and don't yet have solid flight data as it's been cold and windy here in UK for a few weeks now.

Thank you for the reply.

angusc said:
Yes works without any error messages..
Yes will charge from standard Mavic charger providing you don't damage the battery controller board.

For your suggested arrangement you could drill in to the top of the bottom battery and then solder on the second battery cells to the main battery board. Or are you thinking to make a completely new assembly inside your printed case/housing?

I'm still in testing mode with my setup and don't yet have solid flight data as it's been cold and windy here in UK for a few weeks now.

Thank you for the reply. Im thinking to create a completely new assembly in the most compact and streamline housing.

Nofate · Dec 19, 2017

Absolutely in LOVE with these 3600's. I have about 8 flights on them so far (Stock Pack + Protek 3600 pack in parallel) and it has taken my flight times on the stock pack that averaged 18-20min with a mix of sport mode flying and hovering ( I love going out for miles exploring in the AZ desert) to 34 to 37min.

My Average distance now is 65,000- 70,000 ft. Havent tried for max distance yet, just messing around, but will soon. Zero problems with charging or flying, the Mavic flys exactly the same, save for a bit higher RPM.

I am using the Platinum Props. I have been using the SMATREE A/C adapter which pumps out 6.6 amps and charges them in just over an hour. I have been using a wattmater to monitor how much I am putting back in the pack when I charge it, so far is been within 10% (pumping back in around 6500-6800mah when I shut them down at 3.45v per cell.

Still working on the exact resistor value for the current sensing, the resistor value (.005mohm) is making the Mavic think it still has 60% left at 3.45. When I find the correct value I will report back. Been limited on time due to Work so taking longer then expected. Below are the pics on how to do the mod, I highly recommend this over connecting to the Mavics main board as there is no chance of getting battery errors this way.

Below are the Pics on how to do the mod, use a digital soldering gun with the temp set to 550F. Use a fine point tip and go to town, much safer and cleaner then a demel. Cleanup the flash left over with a pair of side cutters. The pics make the solder joints look kinda lousy but they are rock solid

Cut the hole on the top for the resistor at 12mm from the top of the case and 12mm from the side. Cut a 12mm Square hole to start, enlarge as you see fit for whatever gauge wires you want to use and access to the current resistor.

Clean the top of the current resistor with a sharp Xacto knife to clean off the varnish so you can solder to it. Drop some solder and a current sensing resistor. (if you skip this step, you will be forced to land as soon as the 3830ma is used so you have to do it). I used .005 which is too low and you will be landing at 3.45 volt with the system still thinking 60% is left,, going to try .01 next and adjust from there

You can also see in the pics how I soldered in the parallel leads and added my own balance taps. I put the plastic back I cut out with hot glue, kinda ugly but does the job and will allow easy access again should I ever need it.

My Pack is covered in ugly electrical tape as I didn't want to wait for my 3 cell packs to arrive so I picked up some 2 cell 3600 from the local hobby store(all they had) and broke them apart and created 3cell packs from them (dont recommend this, very difficult) and I didn't have shrink big enough to fit it.

LOVING the 35+ min flight times and easy 14mile total range these have been providing so far (Original pack netting just half that)

Savixor · Dec 20, 2017

The 3600 protek seems like the best way to go but I wonder how many cycles will you guys get out of them. It is not worth it if it has really low cycle. For example, under 50 cycles but none of you got to the cycle limits yet.

Nofate · Dec 20, 2017

Savixor said:
The 3600 protek seems like the best way to go but I wonder how many cycles will you guys get out of them. It is not worth it if it has really low cycle. For example, under 50 cycles but none of you got to the cycle limits yet.

One would think Cycle life should go up, but time will tell. Normally the stock pack comes back hot with my style of flying. When they are run with the Protek, the temp has dropped significantly as the current demands have effectively been cut in half on the stock pack (and the Protek pack is never even warm). You can see this while flying as the pack temp is about 10C less according to the battery monitor section in the Go4 app.

Now Motor and speed controller life....that is another subject. Its sporting another 230 grams of weight. Is this enough to cause any significant wear on the motors and speed controllers? I doubt it as only extreme temps could do this but I just picked up a thermal temp gun and will be comparing the temp of the motors with the modded pack vs the stock after a full flight and will compare.

Phxbird57 · Dec 20, 2017

here is my flight from yesterday with the Protek batteries and the Platinum props on. The data is from the dat file on board, the data file on my phone was deleted or not saved. Dashware was having some problem with the data. you will see the data freeze up. Around 33k.

Phxbird57 · Dec 20, 2017

Nofate said:
Absolutely in LOVE with these 3600's. I have about 8 flights on them so far (Stock Pack + Protek 3600 pack in parallel) and it has taken my flight times on the stock pack that averaged 18-20min with a mix of sport mode flying and hovering ( I love going out for miles exploring in the AZ desert) to 34 to 37min.

My Average distance now is 65,000- 70,000 ft. Havent tried for max distance yet, just messing around, but will soon. Zero problems with charging or flying, the Mavic flys exactly the same, save for a bit higher RPM.

I am using the Platinum Props. I have been using the SMATREE A/C adapter which pumps out 6.6 amps and charges them in just over an hour. I have been using a wattmater to monitor how much I am putting back in the pack when I charge it, so far is been within 10% (pumping back in around 6500-6800mah when I shut them down at 3.45v per cell.

Still working on the exact resistor value for the current sensing, the resistor value (.005mohm) is making the Mavic think it still has 60% left at 3.45. When I find the correct value I will report back. Been limited on time due to Work so taking longer then expected. Below are the pics on how to do the mod, I highly recommend this over connecting to the Mavics main board as there is no chance of getting battery errors this way.

Below are the Pics on how to do the mod, use a digital soldering gun with the temp set to 550F. Use a fine point tip and go to town, much safer and cleaner then a demel. Cleanup the flash left over with a pair of side cutters. The pics make the solder joints look kinda lousy but they are rock solid

Cut the hole on the top for the resistor at 12mm from the top of the case and 12mm from the side. Cut a 12mm Square hole to start, enlarge as you see fit for whatever gauge wires you want to use and access to the current resistor.

Clean the top of the current resistor with a sharp Xacto knife to clean off the varnish so you can solder to it. Drop some solder and a current sensing resistor. (if you skip this step, you will be forced to land as soon as the 3830ma is used so you have to do it). I used .005 which is too low and you will be landing at 3.45 volt with the system still thinking 60% is left,, going to try .01 next and adjust from there

You can also see in the pics how I soldered in the parallel leads and added my own balance taps. I put the plastic back I cut out with hot glue, kinda ugly but does the job and will allow easy access again should I ever need it.

My Pack is covered in ugly electrical tape as I didn't want to wait for my 3 cell packs to arrive so I picked up some 2 cell 3600 from the local hobby store(all they had) and broke them apart and created 3cell packs from them (dont recommend this, very difficult) and I didn't have shrink big enough to fit it.

LOVING the 35+ min flight times and easy 14mile total range these have been providing so far (Original pack netting just half that)

View attachment 26981 View attachment 26982 View attachment 26983 View attachment 26984 View attachment 26985 View attachment 26986 View attachment 26987

interesting setup Nofate. and what part of the state are you flying in?

Phxbird57 · Dec 20, 2017

Nofate said:
One would think Cycle life should go up, but time will tell. Normally the stock pack comes back hot with my style of flying. When they are run with the Protek, the temp has dropped significantly as the current demands have effectively been cut in half on the stock pack (and the Protek pack is never even warm). You can see this while flying as the pack temp is about 10C less according to the battery monitor section in the Go4 app.

Now Motor and speed controller life....that is another subject. Its sporting another 230 grams of weight. Is this enough to cause any significant wear on the motors and speed controllers? I doubt it as only extreme temps could do this but I just picked up a thermal temp gun and will be comparing the temp of the motors with the modded pack vs the stock after a full flight and will compare.

After my long flight I checked the internal data file and it shown main battery temp was at 117 degrees. Air temp was in the mid 60's. that was after 43 minutes of flying and sucking the batteries down to
cell 1 2.031,cell 2 2.769 cell 3 2.527. I can't understand way it would not stay flying

dirtybum · Dec 20, 2017

Savixor said:
The 3600 protek seems like the best way to go but I wonder how many cycles will you guys get out of them. It is not worth it if it has really low cycle. For example, under 50 cycles but none of you got to the cycle limits yet.

Most brands that carry silicone graphene batteries claim they have a longer cycle life than standard lipo chemistry. Which means you can expect to at least get twice as many cycles than you will out of your DJI battery. The problem with other graphene batteries on the market, they are very heavy, these Proteks are surprisingly light. And they're obviously bulletproof if Phoenix can run them down as low as he did and they still start charging without some doctoring[emoji41]
This is from the Protek website [

Nofate · Dec 21, 2017

Phxbird57 said:
interesting setup Nofate. and what part of the state are you flying in?

I have been flying all the way out in Whittman (Bell & 219th ave), Santan Mountains, and Casa Grande / Tucson mostly lately (Picacho Peak area). I travel the state quite a bit for work so I try to sneak in some flights when possible.

I just watched your latest video, nice run by the way! I recognize the area, looks like Price Road. I sometimes fly there too. We will have to meet up sometime. My Buddy has a Mavic also (have some really sweet in-flight footage im uploading soon) and I just got the wife one for Christmas. We could get a squadron of these in the air =)

Here is that video I spoke of. The second one is what made me want to mod the battery for more flight time as right when I reached Picacho Peak, it was flagging me for RTH (parked about 3.5 miles from the Picacho). Can't wait to try it with the new pack and additional 15min of flight time =)

Phxbird57 · Dec 21, 2017

This is from the second leg of my flight from the other day. I came back from 46K had 25% battery thought I would try for a short 1.5 mile trip. The total distance is from both flights and the voltage of cell 1 data is from ( as all the data) data file from the Mavic.

Xtreme Drone Pilot · Dec 21, 2017

Nofate said:
Casa Grande / Tucson mostly lately (Picacho Peak area)

Careful with Picacho, Newman's, and other vertical cliffs in Arizona - they are frequently jumped by BASE jumpers. That would be a near 100% fatality.

MacIak · Dec 21, 2017

Phxbird57 said:
After my long flight I checked the internal data file and it shown main battery temp was at 117 degrees. Air temp was in the mid 60's. that was after 43 minutes of flying and sucking the batteries down to
cell 1 2.031,cell 2 2.769 cell 3 2.527. I can't understand way it would not stay flying

How is it possible you suck the batteries down that low? Those should be unusable?!

Phxbird57 · Dec 21, 2017

MacIak said:
How is it possible you suck the batteries down that low? Those should be unusable?!

I'll let you know the next time I use them. Watch the video I post part 2. it show cell 1 voltage.

chazz · Dec 21, 2017

Phxbird57 said:
I'll let you know the next time I use them. Watch the video I post part 2. it show cell 1 voltage.

Were you able to get them back to storage voltage?

Phxbird57 · Dec 21, 2017

chazz said:
Were you able to get them back to storage voltage?

All 3 of the batteries came back up.

chazz · Dec 21, 2017

I got a couple of those protek 4s 4200's. I checked the resistance with a meter i have that checks resistance and C rating and the Protek charger that i have that has a mohm reading . My Protek charger shows 59mohm total pack resistance and the other meter reads about 7.5 mOhms per cell and a C rating of 13 to 14C. The batteries aren't as advertised. They are still a good battery for what we need and they are very comparable to the MS lihv's but the 100C rating isn't true. The MS lihv's are rated at 10C and they measure between 11 and 14C...If I would have bought these needing the 100C for something other then the Mav i would have returned them. But i'm glad they came in I've been waiting awhile and i got the 3.6's and 8.5s coming maybe next week and hopefully i get some time to test. I did plug the 4s charged to 15.2V into the battery board to test and the bird fires up NP. I didn't fly it i just let it idle for a few minutes and it seems the cells run down evenly. So sooner then later ill charge it to 17V and hope it doesn't fry something I guess we'll see.