Let’s do a Mod Mavic Pilots

[redserv]

This just keeps getting better.

 

[Texas Mavic]

Wow that’s awesome work.

 

[Texas Mavic]

Just gave these 2700mah Tenergy’s a whirl. Dual mounted, XT60’s, into the battery clip. Did a hover test. This is the result. 28 minutes 10 seconds. Landing at what the screen tells me is 4%. But looking at the voltage, across the cells, I believe there was more battery to burn, but the Mavic can not recognize it. So I would feel comfortable sending this down range long distance. I consider this a success. Any ideas?

 

[mnis]

Just gave these 2700mah Tenergy’s a whirl. Dual mounted, XT60’s, into the battery clip. Did a hover test. This is the result. 28 minutes 10 seconds. Landing at what the screen tells me is 4%. But looking at the voltage, across the cells, I believe there was more battery to burn, but the Mavic can not recognize it. So I would feel comfortable sending this down range long distance. I consider this a success. Any ideas?

Wow 60Wh extra, and then only about 7 minutes more flight time? Sorry, but that sounds like a big waste to me.

I have to admit that I have not done similar experiments yet because I fear that the Mavic will lose its agility. And as far as I can remember, I was able to fly for 25 minutes with a single new M1x battery until about 6 percent was left. But of course, I usually land between 30 and 20 percent, which is about 19 to 21 minutes.

For this piggy-back thing that almost everyone likes to do because it's easy to implement, I can not be so excited.

But if I wanted to try something like that, then I would use Li-HV's. These batteries have the same voltage level as the DJI OEM's and usually weigh much less than normal LiPo's with the same capacity.

Nevertheless, I prefer to stick to this other 3S-2P thing, because I expect a much better result

Oh, and with almost 57 degrees Celsius, the main battery is already very close to self-destruction, which begins to my knowledge at 60 degrees. If the temperature was just so high at the end, then maybe it's OK, but that should not be considered as normal during half the flight time I think ...

 

[Texas Mavic]

Waste of time for you, but I am getting more flight time than stock batteries and it suits my purpose. 28 minutes flight time? A waste of time to you? Post your results then, tell me how to get more flight time. That’s what I am here doing. You so far have theories, I’m out here testing. These readings suit me, I’m happy with them. If you can show us all something better please by all means.

 

[Texas Mavic]

I genuinely am looking to accomplish extra flight time. Please seriously show me some easier way that you have done so I can do it myself.

 

[Texas Mavic]

I live in Houston Texas, brand new batteries may get me 22 minutes. Just seems to be the way it is.

 

[mnis]

Waste of time for you, but I am getting more flight time than stock batteries and it suits my purpose. 28 minutes flight time? A waste of time to you? Post your results then, tell me how to get more flight time. That’s what I am here doing. You so far have theories, I’m out here testing. These readings suit me, I’m happy with them. If you can show us all something better please by all means.

I already wrote that I had not done any similar tests ... right? I did not claim to be able to do anything better And of course I wrote how I see the whole thing, and maybe want to tackle later. This only shows my general interest in doing something similar...

I'm really happy for you and everyone else when it gives you more flight time and expectations have been met or exceeded...Only my personal enthusiasm is still low, but this has no meaning for your good cause...

I am pleased that you have published your test results, and I am very curious if you can achieve even better results.

Your post ended with: Any Ideas?
One of my ideas was to use LiHv's instead of ordinary LiPo's.

But 60Wh in addition are significantly more than the 43.6Wh of one OEM battery. For me, it's hard to understand that almost 104Wh only give 28 minutes of flight time. Unfortunately you have not written what such a 2700mAh battery weighs ...?

It is a very exciting topic. I have no reason or motivation to make it a bad thing. And as soon as I did something similar, it will not be a secret

 

[Texas Mavic]

The variable here is the reading on screen isn’t actually correct. It doesn’t have the ability to read across all cells. So at almost 11 volts, the intelligent battery system is in lack of better terms assuming it is just the one Mavic battery. So all the safety landing protocols will take effect. However I got the batteries on a
Multimeter when I got home and the 2700mah batteries were both at 11.1 volts. That tells me that if there is a way to override the warnings, and I didn’t have to fight the Mavic landing because it isn’t aware of the extra power at hand, I can only assume I had 5+ more minutes if not more of battery reserve.
So the next step is to get into Assistant 2 and see if it’s possible to change battery parameters

 

[Texas Mavic]

I originally used to 3000mah LiHv’s. Fully charged they charged the Mavic battery and gave immediate battery warnings so I aborted. Round 2 of that test, I rolled the charge back on the 3000mah lihvs, to 12.4. I got 30 minutes hover time. But cell 2 on my Mavic battery took a dump, my battery swole up, and it’s now dismantled ready to be a 2nd support battery stated earlier...when I can get to it.

 

[mnis]

I can only guess what exactly happened. But it could not have been an overcharge, maybe it was an overheating thing, or caused by a storage problem ...

All this should not happen if the more complicated method I've described before is applied, but that's as I said (still) only theory. I will definitely try it as soon as I discover two cheap new M1x batteries to replace two old batteries. If the old batteries have about the same remaining capacity, it should work as well ...

 

[Texas Mavic]

Ok great keep us posted.

 

[Texas Mavic]

I can only guess what exactly happened. But it could not have been an overcharge, maybe it was an overheating thing, or caused by a storage problem ...

All this should not happen if the more complicated method I've described before is applied, but that's as I said (still) only theory. I will definitely try it as soon as I discover two cheap new M1x batteries to replace two old batteries. If the old batteries have about the same remaining capacity, it should work as well ...

Have you done a battery mod before?

 

[mnis]

Have you done a battery mod before?

Yes, but not yet on a DJI product.

 

[mnis]

I mainly build (non-commercial) larger battery packs from 50Wh to about 1000Wh. Usually there are Li-Ion round cell battery packs custom-made for various applications, such as in the RC (non-racing) sector for large ships or heavy land vehicles...
The big green battery pack on this little workbench is for example 4S-8P (32x Samsung INR18650-35E) with about 414Wh (14.8V / 28Ah)...And it only weighs 1825 grams

 

[Texas Mavic]

Get to work, we could use some serious input. So I have found a way to change battery parameters in Assistant 2. You can switch it to a non DJi battery, you can remove the auto land at lower voltages. You can also set the voltages to lower more realistically safe voltages.

 

[Texas Mavic]

Oddly you can even switch to a 4S battery. Very very interesting.

 

[mnis]

I used DJI Assistant so far only for firmware updates, otherwise I have no idea ...

Oh, I would like to immediately try to realize my mental Mavic battery mod

But right now I'm building different little chargers and still have to do some tests. I also have to design and print enclosures for these chargers. Only then can I start a new project.

In the meantime, I'm looking for two new non DJI Mavic batteries. But so far, the price per piece is around 65 Euro, and I hope to get some soon for about 50 Euro each...

The cells of the OEM batteries are lying horizontally one above the other. With my mod, I want to arrange the six cells standing side by side in the battery compartment and design a thin retaining frame for it. The battery will protrude slightly beyond the battery compartment, which should not be a problem. And if the cells are next to each other, then swelling should not immediately cause the battery to pop out...

But here comes the next problem, because the battery connectors will be farther apart, and I need some connection element...???

There is still much to tinker about ...

 

[Texas Mavic]

Level with the battery compartment, the propellers hit or clip anything protruding. Has to be below the battery line. Please keep in mind, you will have to modify the battery parameters, in what they call “debug” mode in Assistant 2, or you will have odd unrelative battery readings, as I stated above.

 

[mnis]

I think I checked it once, and I saw that the tips of the propellers did not reach the battery. But I will check it again with the three available variants 8330F, 8331F and MAS ... Then I will try to get to know Assistant closer ... stay tuned