Dual Battery Mod

[Ed209]

It doesn't recognise the extra capacity but it does seem to limit the amount of mah going through it e.g. With 2 x 5200's (no DJI battery in this instance) both wired to the unswitched side, it only let through 4480ish mah (the same as the standard battery). When I moved one of the 5200's to the switched side then it fully utilised that battery and not as much from the battery on the unswitched side (I'm guessing that the board limits it).

The main issue that I had was that the board kept going into different states. I found that sometimes it would work fine then when it locked out, the 5 second reset would sometimes get it to work again, then when that didn't work, 5 second press followed by a few seconds of charging to trigger a reset..... then when that didn't work I had to actually charge a battery through the board and convince it that it was fully charged again (it wouldn't always reset the charge % unless I could trick it into thinking that it had actually charged its battery again).

The battery manager doesn't like being disconnected and reconnected to batteries all of the time, particularly when they are at different charge states.
I considered using a small mah Lipo permanently connected to the battery manager in order to keep it alive (a 1200mah would fit neatly into the battery compartment) and connect 2 bigger batteries to do most of the work. This way, although I would have to charge the 1200mah (through the battery manager) it is a small battery and would charge quickly).

Anyway, it has proved to be a pain in the *** so I just have put that plan on ice and just hard-wired some XT60 connectors straight into the bird and use unmodified batteries plus the extra LiHV's


Sent from my iPad using PhantomPilots mobile app

Wow that does sound like a mess. The board is measuring the charging so you couldn't even charge the battery on another charger and then connect to the board. That sucks. They have it locked down pretty good it seems. Good thing the main DJI battery is a pretty good one.

 

[Ed209]

At first I tapped into the balance plug, but there isn't really any need unless you are charging (I have only modded one of my 4 DJI batteries).


Sent from my iPad using PhantomPilots mobile app

Got ya. I was thinking tapping into the balance plugs so cell voltage would be readable in DJI Go. Or is the cell voltage read without those 5 balance wires? The 5 balance wires are there just for the charging?

 

[hebs]

That's interesting I didn't know you still had the additional weight of the smart battery, pretty gutsy and obviously I can try the same thing myself but I'd be interested if you had a video of some of the heavier stuff to see how it handled for you! Thanks for testing

I'll see if I can get some video this weekend. It was quite sluggish but the wind could have made it feel worse. It certainly descended quicker!

The motors didn't feel any warmer than usual but that could be a different story on a calm warm day.


Sent from my iPad using PhantomPilots mobile app

 

[Ed209]

I'll see if I can get some video this weekend. It was quite sluggish but the wind could have made it feel worse. It certainly descended quicker!

That's would be freakin scary when trying to fight the auto land!

 

[hebs]

Got ya. I was thinking tapping into the balance plugs so cell voltage would be readable in DJI Go. Or is the cell voltage read without those 5 balance wires? The 5 balance wires are there just for the charging?

I managed to break a couple of boards and had one that switched the battery manager on and communicated to the bird, but didn't actually power the bird on - the externals completely ran the bird.

The balance cable 'tap' displayed the cell voltages and the overall voltage (% remaining in the app) is better bizarrely taken from the switched side. I tested it with 2 X 6600's (no DJI battery) and 1 X 1800 running the battery manager and thought that I was on for a world record when I still had 94% left after 28 minutes - in reality, the 1800 had 94% left but when I checked the cell voltages (of the 6600's) they were getting a bit low and I landed - if I hadn't noticed, the bird would have dropped and I would have depleted my 6600's to 0%, a potentially expensive mistake!

So.... I'm gonna leave the battery manager for a bit


Sent from my iPad using PhantomPilots mobile app

 

[hebs]

Wow that does sound like a mess. The board is measuring the charging so you couldn't even charge the battery on another charger and then connect to the board. That sucks. They have it locked down pretty good it seems. Good thing the main DJI battery is a pretty good one.

The strange thing is that it would sometimes behave fine and I could swap in charged batteries and a reset/quick charge would clear it - other times (and I can't figure out exactly why) it would lock completely and I'd have to charge through it.


Sent from my iPad using PhantomPilots mobile app

 

[dirtybum]

That's would be freakin scary when trying to fight the auto land!

I'll see if I can get some video this weekend. It was quite sluggish but the wind could have made it feel worse. It certainly descended quicker!

The motors didn't feel any warmer than usual but that could be a different story on a calm warm day.


Sent from my iPad using PhantomPilots mobile app

I did notice when just having the one big 5.2 on the rear earlier and some pretty stiff wins, when you press land and it slowly decends it drifts off with the wind and will miss your mark by about 25 feet. The way to counter this is always have the back of the aircraft facing the direction the wind is coming from and then it lands on target. I imagine this would be just as useful when landing with the controller sticks. However I run my battery down so far that it's usually auto landing when it arrives anyhow, and if I do have a percentage to spare I will push the land button in the app because I'm using a tripod I can run over and hand catch it. So , geese land into the wind, drones land against the wind (if you have a heavy battery on the back)

 

[hebs]

I got 39m45s with the DJI bat + 5200.

Is that 1 or 2 x 5200's?


Sent from my iPad using PhantomPilots mobile app

 

[hebs]

I'd be interested if you had a video of some of the heavier stuff to see how it handled for you! Thanks for testing

I took the bird to work and had a play with the different batteries.
in this video I land with the 4000s attached (34mins) and swap to the 2800s.
The wind was quite strong and I had an intermittent gimbal problem. It's also a bit tricky flying from a moving vehicle!

 

[dsd317]

I took the bird to work and had a play with the different batteries.
in this video I land with the 4000s attached (34mins) and swap to the 2800s.
The wind was quite strong and I had an intermittent gimbal problem. It's also a bit tricky flying from a moving vehicle!

Nice vehicle! Where can I get one of those?

 

[MVodhanel]

I stumbled onto a gem today working on extended flight on my Lite Foot project. I think it is relevant here, and I also think it might prove to be the serious no-nonsense method to facilitate extended flight on the P3.

If you run power leads direct from battery to ESC board input (you need a way to turn the power off when not using IE: connector, switch) in parallel with the battery manager, the battery manager becomes a voltage only monitor. The percentage will probably not get any lower than 60, or so, but the voltage will go all the way to 3.33 then do a force landing (if you don't land)

I would consider this only for the highly skilled pilots, and I think this is what they would actually want.. Watch the **** voltage. That stupid percentage is, well, stupid.

I stumbled on this tracing symptoms of voltage drop that really shows when these birds get loaded with their added batteries. The battery manager, I think wasn't designed to carry so many amps, So I gave it a little help, and voila!

Anyway enjoy. I will be posting more w/pictures as I finish off extended flight on Light Foot.

 

[dirtybum]

I stumbled onto a gem today working on extended flight on my Lite Foot project. I think it is relevant here, and I also think it might prove to be the serious no-nonsense method to facilitate extended flight on the P3.

If you run power leads direct from battery to ESC board input (you need a way to turn the power off when not using IE: connector, switch) in parallel with the battery manager, the battery manager becomes a voltage only monitor. The percentage will probably not get any lower than 60, or so, but the voltage will go all the way to 3.33 then do a force landing (if you don't land)

I would consider this only for the highly skilled pilots, and I think this is what they would actually want.. Watch the **** voltage. That stupid percentage is, well, stupid.

I stumbled on this tracing symptoms of voltage drop that really shows when these birds get loaded with their added batteries. The battery manager, I think wasn't designed to carry so many amps, So I gave it a little help, and voila!

Anyway enjoy. I will be posting more w/pictures as I finish off extended flight on Light Foot.

O.k! Now were talking! This might be the biggest **** breaking news of this whole entire 5000 post thread. Great job sir, please give some more details of this.

 

[dirtybum]

So you would alter some leads out of the main bat directly to the esc power? What would be the result to leave the main bat alone and run leads from the externals to esc power. Prob no difference cause the bat manager is still in control huh?

 

[sacooke]

So you would alter some leads out of the main bat directly to the esc power? What would be the result to leave the main bat alone and run leads from the externals to esc power. Prob no difference cause the bat manager is still in control huh?

Sounds like you have a hot soldering iron and a pot of coffee brewing.

 

[dirtybum]

This could be big![emoji41]

 

[Ed209]

I stumbled onto a gem today working on extended flight on my Lite Foot project. I think it is relevant here, and I also think it might prove to be the serious no-nonsense method to facilitate extended flight on the P3.

If you run power leads direct from battery to ESC board input (you need a way to turn the power off when not using IE: connector, switch) in parallel with the battery manager, the battery manager becomes a voltage only monitor. The percentage will probably not get any lower than 60, or so, but the voltage will go all the way to 3.33 then do a force landing (if you don't land)

I would consider this only for the highly skilled pilots, and I think this is what they would actually want.. Watch the **** voltage. That stupid percentage is, well, stupid.

I stumbled on this tracing symptoms of voltage drop that really shows when these birds get loaded with their added batteries. The battery manager, I think wasn't designed to carry so many amps, So I gave it a little help, and voila!

Anyway enjoy. I will be posting more w/pictures as I finish off extended flight on Light Foot.

I think I follow you here. Solder leads from the board and terminate with XT60s. Connect ext bat to that.
And this would allow the extra amperage to be fed directly to the bird instead of coming through the DJI bat and bat mgr? Do the batteries still drain at the same rate? I'd imagine so, I think! I wonder how the flight time/calculation would be affected? I guess it doesn't matter since you're just watching voltage at this point. And if all cells are draining equally, you know how much you have left. Interesting....

 

[hebs]

I stumbled onto a gem today working on extended flight ........ The percentage will probably not get any lower than 60, or so, but the voltage will go all the way to 3.33 then do a force landing (if you don't land)

I would consider this only for the highly skilled pilots, and I think this is what they would actually want.. Watch the **** voltage. That stupid percentage is, well, stupid.

This is very similar behaviour to what a talked about in posts 1306 &1312.

It appears that the battery manager chokes the output to the bird quite a bit. Are you talking about a bypass with a switch to send some of the current around the battery manager?


Sent from my iPad using PhantomPilots mobile app

 

[maxwell smart]

Mine is wired straight to the board inside the bird. I also have the bird side mod.Witch is booster for bird side video signal.

 

[Silverwingflinx]

Mine is wired straight to the board inside the bird. I also have the bird side mod.Witch is booster for bird side video signal.

hello max so what kind of flite times do you get with your set up.what kind of set up you running.so i guess if you wire the batt leads to the mother board this will give you longer flite times.i have a second P3A i could try this FPV CUSTOMS first mod was like this.any ways would like to know more about your set up.thax

 

[maxwell smart]

hello max so what kind of flite times do you get with your set up.what kind of set up you running.so i guess if you wire the batt leads to the mother board this will give you longer flite times.i have a second P3A i could try this FPV CUSTOMS first mod was like this.any ways would like to know more about your set up.thax

Hi there.. I am still trying to get good signal range. Am also looking at battery's for more flight time. The Horizon battery plug and play is top on my list. Weather is not good at this time. I work full time so only have the weekend to fly. I have upgraded my bird and transmitter extensively. All a work in progress. I will shear any details if they are worth sharing. But I am still modding stuff.