Mavic Pro Battery Mod

[Gh0stxSinghx]

Thank you!

 

[El_talento85]

donde puedo comprar el adaptador para las baterias extras

 

[lolo780]

Ordered some of those Thunder Power batteries today. Anybody have any feedback on them? I've been flying with Proteks but I lost 2 of them in a crash and the other 2 are starting to swell. I'd been charging them on 5 amps and ran them down to 0 a few times. I might get some more Proteks but wanted to give the Thunders a try. They seem to have a good power/weight ratio and more total power than the Proteks.

I've used Thunderpower since I started flying the Mavics and they've always been good. I noticed the last packs I bought during the thanksgiving sale weighed more than the original ones from last summer. Different batch of cells maybe? Performance seems equal, but I was dissapointed they gained a few grams.

 

[lolo780]

Yes, the bottom end is progressive and the main battery hits zero while still in flight. Over a field I was able to fly on "0%" at low alt for over 1 minute. If you've ever flow long range on a Spark it's similar.

 

[lolo780]

I fly with non-dji battery set, so the only auto landing is the critical one that cannot be disabled. I do alter the downward speeds though.

 

[lolo780]

I set -1 to give a smooth descent. So if you're 100m up and travelling 15m/s it will glide in and minimize energy consumption.

 

[pcath]

Hi, I'm frenchflyer !!
Can i use this battery :Batterie Lithium Ion 3S 7000 mAh 2C (XT60) - Titan

Thanks

 

[lolo780]

Lol I tested this last night and it dropped out of the sky abruptly. I wasn't running externals. Luckily I was only a few feet off the ground.

Pushing the stock battery is a great way to crash I have found.

 

[Deadleg]

Hi, I'm frenchflyer !!
Can i use this battery :Batterie Lithium Ion 3S 7000 mAh 2C (XT60) - Titan

Thanks

The answer is . . it depends. If you want to use it with the Mavic there are several problems. Firstly in order to use the full 7000 mAh you need to run the battery down to 8.4v. Clearly if you try to do this you are in danger of damaging the Mavic battery. Secondly the Mavic LiPo battery voltage does not decrease as fast as the Titan LiIon battery. This will cause the Mavic battery to almost completely discharge before the Titan energy starts to be used. At this point the Titan battery is working on its own, without help from the Mavic battery, and will be supplying most of the current needed by the Mavic. This means that in the later part of the flight you will have to limit the Mavic performance to a light cruise, or you will be in danger of passing the current limit of the Titan cells. In short this battery is not compatible with the Mavic battery. If you want to use it, first remove the Mavic battery, and be careful of over-current during the final phases of the flight.

If you are interested in using LiIon batteries with the Mavic then take out the Mavic battery and replace it with LiIon cells wired as a 4s2p or 4s3p battery. You will then be able to use the full capacity of the the LiIon cells. I have just been testing a 4s2p LiIon battery, and I find that it will hover for 33 mins, compared to 24 mins with stock battery under the same conditions.

 

[efowler]

So I decided to brute force it to the distance limit today. Strapped on 3 Proteks and just powered out there with stock Mavic and Platinum propellers. 58,820ft out and back. I'll post up the video later.

Here is video. The signal with 4Hawks XR panel is awesome when boosted. I had some big interference from those high tension power lines I flew over, but once I got far enough away, signal came back strong!

Wow - Very Cool CyberNate! I noticed that you were 31mph out and 33mph on the way back - obviously light wind. Did you have it in non-sport mode with full forward the whole time?? - it seems like you would have had to do that to keep the speed so steady.

I was also very surprised you were only 150' on the way out and 162 on the way back - crazy that you didn't need any more altitude that that. i have my three battery pack set up and have not been on a distance flight yet but when flying it close it seemed pretty heavy. Obviously the motors can handle it after watching you video!! Have you done anything to lighten your stock Mavic?

One more question, I noticed a redundant compass message flash on your screen in the video. On one of my test flights my MavickPro tried to fly away on me and was uncontrollable. I am thinking I will try Lolo's compass mod next time. Have you ever had any problems with you compass in this configuration??

 

[action]

If you are interested in using LiIon batteries with the Mavic then take out the Mavic battery and replace it with LiIon cells wired as a 4s2p or 4s3p battery. You will then be able to use the full capacity of the the LiIon cells. I have just been testing a 4s2p LiIon battery, and I find that it will hover for 33 mins, compared to 24 mins with stock battery under the same conditions.

What do I need to change in assistance in order to accept 4s Pack?

I guess you recommend using the LiIon‘s without the intelligent battery plate?

thanks and cheers

 

[Deadleg]

What do I need to change in assistance in order to accept 4s Pack?

I guess you recommend using the LiIon‘s without the intelligent battery plate?

thanks and cheers

You do not need to change any parameters - just plug in and go. But if you want to read the battery voltage, you have to take the Mavic battery apart and remove the battery management board. Then you have to connect the 4s battery to the 3s control board . . and this is a bit tricky. Mavic batteries are a bit pricey and it's not difficult to blow up the battery or the control board. Then you have to find a way to connect the control board back to the Mavic, and a way to mount the batteries. This is not for the faint-hearted! If you still want to try it, go back a few pages in this thread and see how I did it . .

 

[mlash]

Hi, I'm frenchflyer !!
Can i use this battery :Batterie Lithium Ion 3S 7000 mAh 2C (XT60) - Titan

Thanks

I have tried this battery, many others here have tried it as well and it's just not a good battery for the Mavic.

 

[pcath]

Thanks for all reply !! which LI po battery advice me ?

 

[mavicpro1000]

You do not need to change any parameters - just plug in and go. But if you want to read the battery voltage, you have to take the Mavic battery apart and remove the battery management board. Then you have to connect the 4s battery to the 3s control board . . and this is a bit tricky. Mavic batteries are a bit pricey and it's not difficult to blow up the battery or the control board. Then you have to find a way to connect the control board back to the Mavic, and a way to mount the batteries. This is not for the faint-hearted! If you still want to try it, go back a few pages in this thread and see how I did it . .

Interesting this. Are you saying the Mavic will happily operate on 16.8v???

 

[Deadleg]

I'm a newbie to the distance game, and sorry if this is old stuff, but it would help me a lot if you could put me right on a few points:

1. To judge the turn-around point you need to know how much capacity is left in both internal and external batteries. The app shows the % left in the internal battery, but I guess this may not tell you much about the external. Is battery voltage as a better guide than batt %? Is there a voltage level, say 3.5v which tells you you only have only 5% left in the tank?

2. I guess you need to know the discharge curves of the different batteries. Can you get this information from the suppliers, or independent testers?

3. As you add more batteries the capacity goes up, but the weight also goes up. Does anyone know what effect weight has on Mavic power consumption? Has anyone measured this?

 

[Deadleg]

Interesting this. Are you saying the Mavic will happily operate on 16.8v???

Yes, as far as I can tell from limited tests, all the systems seem to be working at 16.8v. I have to admit this was a surprise . .

I have heard that before. But if you don't do what he is saying, and just use these external batteries along side the stock internal, when you plug them in, the internal battery will start charging and then shut off. I haven't tried this but that's my understanding. Also heard that it flies pretty aggressively with 4s batteries

You may be right, but I don't understand why this should happen. The LiIon will lose voltage much faster than the LiPo, so the Mavic battery should charge the LiIon. But I haven't tried it either, so I can't be sure. Haven't noticed any aggressive behavior yet using the 4s battery, but it's early days . .

 

[Deadleg]

I'm not sure what procedure you are using to start up with the externals but I do the following:
Turn on the Mavic with the internal battery, externals unplugged.
Let it get GPS lock and then plug in the internals and start the motors.
Wait a few seconds to see if the lights on the internals start flashing, indicating that it is charging.
If it's charging, wait till it turns off and then turn it back on. Otherwise, take off and hover.
Once you take off, keep an eye on your voltage/percentage. If it doesn't start dropping after a bit, it probably shut off and you should bring it back in.

Thanks for your feedback . . it's very helpful.

Your start-up procedure looks fine. I don't use the same procedure because I don't use the Mavic battery. I agree with you that during start-up there is a short period where the external charges the Mavic battery.

Yeah, the app only shows the internal battery voltage. If you use externals that track pretty closely to the internals as far as discharge rate and capacity, like the Protek 3600, the battery percentage/voltage shown in the app is still a good indicator as to how much is left in the tank. I haven't flown with externals that don't track that close to the internals yet but I have some on the way. In anticipation of that, made some adjustments to the Mavic parameters such that it will not try to force a landing when the internal gets low.

If you want to know how the battery behaves, just run it till the Mavic internal gets low and then charge your externals. You can see how many amps they take to recharge and thus gauge how close they track to the internal.

As to your last question, obviously the more weight, the more energy spent to keep it in the air. You will notice your RPMS will be higher when hovering once you have external batteries mounted. This extra load can cause the motors to get hot but most people don't have issues with it. I've only flown with 2 externals that weigh 440g total. Some are flying with 660g extra weight but I hear that's about as much as you're going to want to load it with.

What I'm trying to do is predict battery performance from the discharge curves. I can do it pretty well using 18650s because the discharge characteristics at different discharge currents are well documented, but I cannot find the same data sheets for LiPo batteries.

Also I can get battery power and motor power data from my own flights from the FLY.DAT files using Assistant 2, but I need this data from other Mavics using different battery weights, to get a better idea of weight vs power. It makes it easier to decide on the best battery design. Do you have FLY.DAT files from any of your battery test flights that I could look at?

 

[droneuser]

I think a new thread of what battery works, connector's that are need, etc

cause if you are old like me by the time we get to the last page of this thread we forgot what we read already!...lol lol

I have to ask ( sorry if this was talked about before or asked) cant we make our own battery? meaning 3d print a mavic battery "shell" but bigger then take the battery control board out of a mavic battery install it in the 3d shell with the number of cells that is need to get good flight time?

doing it this way would be cleaner and easier? no need to add wires etc?

 

[Deadleg]

zaceshighz: To give you an example, here's some data from a hovering test using the stock battery and low noise carbon props. You can see in these conditions it was using 95 watts to hover. The second graph is for my 4s battery, and you can see that the power required to hover with this battery (an extra 213g) goes up to about 130 watts. If I can combine this with more FLY.DAT data using different types of batteries, I can get a handle on how the Mavic handles the extra weight. Any help would be appreciated.