Mavic Pro Battery Mod

[DeCoY]

My first post

With these battery mods why are you guys not repacking the batteries with new larger cels that can be fitted into the enclosure .
If you can not find suitable cells, why not crack another mavic battery and wire the cells to the balance board in a 2 parallel 4 series config, this will report the correct cell voltage to the drone .
The Balance board only checks voltage to each cell it has no clue what the total capacity is unless there is a coulometer built into the balance board?

Ignore the brand and balance board type, imagine it to be the batery BMS board, I just googled image search for BMS with 2p4s cell configuration.

 

[RocR8d]

So after reading for hours on this thread it seems that the quick link over the battery terminals is hit or miss on proper connection for aux battery drain. I'll be "hard wiring" the connections to the internal connections. I'm going to be modding my MPP this weekend and wanted to know if there had been a realized "sweet spot" for battery size to flight time? I am using two 3000maH LiHV Turnigy's hoping to get up the distance leaderboard

 

[RocR8d]

It seems that most folks gave up interest in long range once the "hard" limit was hit. @CyberNate and @lolo780 seemed to be the last few that hit that...at least in this thread...and for the most part became a dead thread. Here is what I've found reading 212 pages of a thread....

1. Protek 3600 LiHVs were the last great battery that was sweeping the thread. @CyberNate hit the hard limit with 3 of them strapped on.
2. Doing the math, you need minimum ~16.3mAh per gram of battery to make the hard limit.
3. Need platinum props in low wind

What I'm seeing now on Facebook posts is folks like @vincentng making huge 11870mAh 3S2P LiHV batteries that have a battery board that's been "hacked" to that it plugs into the MP with no issues and no need for additional connectors. My questions are:

1. Whose doing this in the states? Vincent is in Taiwan somewhere and shipping for $160 battery would be outrageous.
2. Has someone figured out as he has the ability to get the battery board to work once disconnected from stock cells.

I think we are past the long range race and now I'd like to get to more convenient long range. I've seen a couple of the posts of great looking 3d printed "oversized" casings...which would be a great part of this. Thoughts to the group?

 

[EfterlysT]

Hello. This is my first post here.
To be honest i have not read all 200+ pages in this thread.

I have some issues with my first battery mod attempt on my mavic pro.
After reading alot of threads here and there i noticed that people are using both 11.1v and 11.4v lipos doing this.

I bought 11.1v lipos because it was hard to find the 11.4v ones in my country.

The issue i am facing now is that my originally mavic battery is charging the lipo batterys, when i am out of battery and land the drone dies when i disconnect the lipos. The main DJI battery is totally drained out.

So my question is, will i have to switch to 11.4v lipos for this to work or is there a workaround for this ?

I use a battery adapter to plugin my lipos.

 

[lee82gx]

Hello. This is my first post here.
To be honest i have not read all 200+ pages in this thread.

I have some issues with my first battery mod attempt on my mavic pro.
After reading alot of threads here and there i noticed that people are using both 11.1v and 11.4v lipos doing this.

I bought 11.1v lipos because it was hard to find the 11.4v ones in my country.

The issue i am facing now is that my originally mavic battery is charging the lipo batterys, when i am out of battery and land the drone dies when i disconnect the lipos. The main DJI battery is totally drained out.

So my question is, will i have to switch to 11.4v lipos for this to work or is there a workaround for this ?

I use a battery adapter to plugin my lipos.

what is the voltage of the internal battery vs external battery at landing?

What kind of battery adapter? I imagine you are connecting externally via the blade connectors. If that connection as not good ie high resistance, then the external battery will not drain concurrently. I suggest you solder the connectors.

I also suggest not to run down your batteries so low, that is to land earlier.
Plenty of folks in here used standard lipos without too much trouble so as long as your lipos are decent they should work.

 

[lee82gx]

It seems that most folks gave up interest in long range once the "hard" limit was hit. @CyberNate and @lolo780 seemed to be the last few that hit that...at least in this thread...and for the most part became a dead thread. Here is what I've found reading 212 pages of a thread....

1. Protek 3600 LiHVs were the last great battery that was sweeping the thread. @CyberNate hit the hard limit with 3 of them strapped on.
2. Doing the math, you need minimum ~16.3mAh per gram of battery to make the hard limit.
3. Need platinum props in low wind

What I'm seeing now on Facebook posts is folks like @vincentng making huge 11870mAh 3S2P LiHV batteries that have a battery board that's been "hacked" to that it plugs into the MP with no issues and no need for additional connectors. My questions are:

1. Whose doing this in the states? Vincent is in Taiwan somewhere and shipping for $160 battery would be outrageous.
2. Has someone figured out as he has the ability to get the battery board to work once disconnected from stock cells.

I think we are past the long range race and now I'd like to get to more convenient long range. I've seen a couple of the posts of great looking 3d printed "oversized" casings...which would be a great part of this. Thoughts to the group?View attachment 95652

I think Vincent is in Singapore. Both he and some sellers in taobao China are selling “double batteries”. My understanding is Vincent Ng also sells the board as you say that can be used to plug any lipo via xt-60, monitored via voltage only. Another version is with cells from dji inspire that are very high capacity and somehow programmed to be read properly by the aircraft and dji go, so you can literally see the current usage.

Im also very late to this game and will receive my 2200 packs soon. Will connect externally first but I guess eventually I will solder direct.
What’s wrong with Velcro and Velcro straps that makes you want to go for a hard saddle?

for my case I also just want to have 14km round trip range nothing spectacular or record breaking. I plan to start with a single battery and if necessary a double battery at the sides.

 

[EfterlysT]

what is the voltage of the internal battery vs external battery at landing?

What kind of battery adapter? I imagine you are connecting externally via the blade connectors. If that connection as not good ie high resistance, then the external battery will not drain concurrently. I suggest you solder the connectors.

I also suggest not to run down your batteries so low, that is to land earlier.
Plenty of folks in here used standard lipos without too much trouble so as long as your lipos are decent they should work.

The internal battery is completely empty when i take it down at 10% warning. When disconnecting the lipo the drone dies. So, i am practically flying on lipo only at the end.
The lipo batteries hold like 25-40% juice afterwards.

I use this adapter:

DJI Mavic Pro / Platinum Power Adaptor Dual XT60

Obtain a wider range and increased flight time with this battery adaptor fitted with a XT60 connection. Take a look at the range you could be getting picture to the right. You have

www.uavmods.co.uk

Maybe soldering is the way to go then. I have also ordered a couple of 11.4v lipos. But right now i am sitting with a total of six 11.1v lipos so it would be nice if i could get it to work

 

[lee82gx]

The internal battery is completely empty when i take it down at 10% warning. When disconnecting the lipo the drone dies. So, i am practically flying on lipo only at the end.
The lipo batteries hold like 25-40% juice afterwards.

I use this adapter:

DJI Mavic Pro / Platinum Power Adaptor Dual XT60

Obtain a wider range and increased flight time with this battery adaptor fitted with a XT60 connection. Take a look at the range you could be getting picture to the right. You have

www.uavmods.co.uk

Maybe soldering is the way to go then. I have also ordered a couple of 11.4v lipos. But right now i am sitting with a total of six 11.1v lipos so it would be nice if i could get it to work

You can switch off the internal battery first before disconnecting the external pack. Either way something doesn’t add up. Do check voltage of both packs at landing.
If the internal pack is down to less voltage than the external, then near the end the external pack will be charging the internal pack instead. How many mah for the external and how long you’re flying? A log will be useful

 

[GadgetGuy]

You can switch off the internal battery first before disconnecting the external pack. Either way something doesn’t add up. Do check voltage of both packs at landing.
If the internal pack is down to less voltage than the external, then near the end the external pack will be charging the internal pack instead. How many mah for the external and how long you’re flying? A log will be useful

The traditional method was to boot up with the internal battery first, then hook up the externals. After landing, disconnect the externals first, and then shut off the internal battery, reversing the process. The external batteries must always be bled off, to have a lower voltage than the internal battery before flight. If the externals are at a higher voltage than the internal battery after hook up, just before launch, the internal battery will shut off, and start to be charged by the external batteries.

 

[EfterlysT]

You can switch off the internal battery first before disconnecting the external pack. Either way something doesn’t add up. Do check voltage of both packs at landing.
If the internal pack is down to less voltage than the external, then near the end the external pack will be charging the internal pack instead. How many mah for the external and how long you’re flying? A log will be useful

I spent hours today trying to solve the kinks.
Not sure if i am more wiser now but atleast i got a hover flight made.
It seem like it only works with one of my three original DJI batterys somehow !?
With two 2400mah lipos i hovered for a total 35min six seconds.
I landed at 5% battery left, lipos had lower then 25% each.

The traditional method was to boot up with the internal battery first, then hook up the externals. After landing, disconnect the externals first, and then shut off the internal battery, reversing the process. The external batteries must always be bled off, to have a lower voltage than the internal battery before flight. If the externals are at a higher voltage than the internal battery after hook up, just before launch, the internal battery will shut off, and start to be charged by the external batteries.

I have always connected/disconnected the lipo batteries that way.
On my 35min + hover flight i used fully charged lipos.

 

[lee82gx]

I spent hours today trying to solve the kinks.
Not sure if i am more wiser now but atleast i got a hover flight made.
It seem like it only works with one of my three original DJI batterys somehow !?
With two 2400mah lipos i hovered for a total 35min six seconds.
I landed at 5% battery left, lipos had lower then 25% each.


I have always connected/disconnected the lipo batteries that way.
On my 35min + hover flight i used fully charged lipos.

so reaching 35 mins is already good, my question is when you land what is the voltage of the external pack? they should be similar to the internal pack if no loss is at the connectors. And the external packs have not so much Internal resistance as internal.

 

[EfterlysT]

so reaching 35 mins is already good, my question is when you land what is the voltage of the external pack? they should be similar to the internal pack if no loss is at the connectors. And the external packs have not so much Internal resistance as internal.

I will check some voltages with a multimeter after next flight.

Internal battery reported by DJI GO 4. Totally drained.


Next flight will be more flying due to high temps from hovering. I will also get 4x Turnigy Bolt 2400mAh 11.4v lipos delivered in some days. I think they will be pretty awesome for this.

 

[Cuong]

Hello everyone, sorry for not relative question here. Does anyone here have knowlegde about rc antenna. I have a pair of taoglas antenna, it to big, can I cut some PCB as below picture? Thanks alot

 

[lee82gx]

Hello everyone still watching this thread.

Just to state my recent experience on this topic. Bought 2 11.1V packs, but vendor messed up and sent me 1x2200mah (167g) and 1x1500mah (145g). With both of these I managed to fly 28:30 minutes. RPM at hover was 6800 I think. The front motors were very very hot, not really touchable. The landing voltage was 10.7V with a sharp drop at the end. Wired with 18AWG direct to the power lines internally there was not much loss as both internal and external packs measure roughly the same voltage at the end. I was not attempting a long distance flight as it was smack in the middle of Covid 19 lockdown and my house is not in a suitable geography. Also, strapping unbalanced weighted packs on either side of the Mavic resulted in the aircraft drifting heavily to one side when it is asked to fly straight. Finally I recall the internal battery going all the way to 64degrees C which was very warm to the touch.

Not being satisfied with the temperatures and messy cabling, I contacted a guy in my country that repaired and even made those "double cell packs".

At the price of US$100, he made and shipped me a double Mavic cell pack with total of 7660mah total, with a new actual Mavic BMS. I just received this yesterday and charged it up with the factory charger.


So I believe these are 3S2P cells, surely. They read voltage fine in the DJI Go 4 app and I think flight time and RTH indicators may not be too far off from estimation either.

First flight : 32:31 with plenty of hovering to take picture of lockdown deserted streets near my house. Landing at 10.8V / 3.6V / 9%
Flight 1

Second flight : 34:17 only hovering with slight winds. Landing at 10.8V / 3.6V / 8%

Both flights came back with the battery at around 50C which was slightly warmer than usual, which was used to be around 45C. I think this is a trade off due to the higher current draw due to weight increase, for sure.

From my scouring of local private selling websites, there are 3 persons capable to re-program the battery board to accept new cells, and these folks also have access to raw DJI cells. So they can definitely make 2P cells. Now they offer 3S2P Mavic cells (7660mah), 3S2P Inspire cells (8560mah), and 3S2P Phantom 4 cells (11740mah).

My 7660 cell pack came in at 405g. When I think about the benefits whereby the there is absolutely 0 modification necessary to the aircraft and the fact that it cost roughly the same as a new factory battery pack, I think its a no brainer to invest in 1. In fact, I may likely forego fly more combos in the future and just get 1 of these to serve together with a single factory pack.

 

[GadgetGuy]

Hello everyone still watching this thread.

Just to state my recent experience on this topic. Bought 2 11.1V packs, but vendor messed up and sent me 1x2200mah (167g) and 1x1500mah (145g). With both of these I managed to fly 28:30 minutes. RPM at hover was 6800 I think. The front motors were very very hot, not really touchable. The landing voltage was 10.7V with a sharp drop at the end. Wired with 18AWG direct to the power lines internally there was not much loss as both internal and external packs measure roughly the same voltage at the end. I was not attempting a long distance flight as it was smack in the middle of Covid 19 lockdown and my house is not in a suitable geography. Also, strapping unbalanced weighted packs on either side of the Mavic resulted in the aircraft drifting heavily to one side when it is asked to fly straight. Finally I recall the internal battery going all the way to 64degrees C which was very warm to the touch.

Not being satisfied with the temperatures and messy cabling, I contacted a guy in my country that repaired and even made those "double cell packs".

At the price of US$100, he made and shipped me a double Mavic cell pack with total of 7660mah total, with a new actual Mavic BMS. I just received this yesterday and charged it up with the factory charger. View attachment 97583
View attachment 97584

So I believe these are 3S2P cells, surely. They read voltage fine in the DJI Go 4 app and I think flight time and RTH indicators may not be too far off from estimation either.

First flight : 32:31 with plenty of hovering to take picture of lockdown deserted streets near my house. Landing at 10.8V / 3.6V / 9%
Flight 1

Second flight : 34:17 only hovering with slight winds. Landing at 10.8V / 3.6V / 8%

Both flights came back with the battery at around 50C which was slightly warmer than usual, which was used to be around 45C. I think this is a trade off due to the higher current draw due to weight increase, for sure.

From my scouring of local private selling websites, there are 3 persons capable to re-program the battery board to accept new cells, and these folks also have access to raw DJI cells. So they can definitely make 2P cells. Now they offer 3S2P Mavic cells (7660mah), 3S2P Inspire cells (8560mah), and 3S2P Phantom 4 cells (11740mah).

My 7660 cell pack came in at 405g. When I think about the benefits whereby the there is absolutely 0 modification necessary to the aircraft and the fact that it cost roughly the same as a new factory battery pack, I think its a no brainer to invest in 1. In fact, I may likely forego fly more combos in the future and just get 1 of these to serve together with a single factory pack.

Any Mavic 2 double cells available?

 

[lee82gx]

Any Mavic 2 double cells available?

Yes. But Mavic 2 is just 4s1p of 3830mah IIRC. So a double pack would be 4S2p 7660mah.

 

[RocR8d]

Yes. But Mavic 2 is just 4s1p of 3830mah IIRC. So a double pack would be 4S2p 7660mah.

Problem is, are any of these “persons” capable of shipping these to the states for a reasonable price?

 

[lee82gx]

Problem is, are any of these “persons” capable of shipping these to the states for a reasonable price?

Its hard to say, maybe if you have a someone coming over, it’d be worth a shot. This guy made my pack in 4hrs and tested 1 charge before shipping to me. Vincent Ng has also been selling Mavic Pro 1 battery board with bring your own XT60 battery that you can couple to any pack....he’s asking for around US$55 and shipping for that may not be too expensive.

 

[lee82gx]

Another bonus for the "Double cell packs". The maker actually programmed the capacity to be 7660mAh so fuel gauge calculations are also accurate. Time of flight remaining is reasonably accurate but definitely not at the beginning when it estimated 42mins of flight, but after a minute or two, the remaining flight time drops like the stock battery.



See the curves for Remaining % and Remaining Cap, they line up nicely. If I'm not mistaken even RTH points are accurate. I just dont have a straight line of sight long enough to test this due to covid lock down.

 

[RocR8d]

Another bonus for the "Double cell packs". The maker actually programmed the capacity to be 7660mAh so fuel gauge calculations are also accurate. Time of flight remaining is reasonably accurate but definitely not at the beginning when it estimated 42mins of flight, but after a minute or two, the remaining flight time drops like the stock battery.


View attachment 97688
See the curves for Remaining % and Remaining Cap, they line up nicely. If I'm not mistaken even RTH points are accurate. I just dont have a straight line of sight long enough to test this due to covid lock down.

Those do look good. I'd love to get one of the 11870 ones from Vincent, just need better shipping rates. I tried the strapped on lipos and the bird just handled so poorly. I like the idea of plug and play and the weight being center mass where it needs to be.