Dual Battery Mod

[Silverwingflinx]

Nice. I might try that. I noticed you have an aftermarket carbon fiber gimbal mount? Do you know if the stock DJi mount is flippable as well?

yes the stock mount is flippable the p3v2 has longer cam cable it should work.

 

[chazz]

It is very very windy today, 20-25mph gusting to 30mph+. These two flights were mostly hovering and out maybe 1,500 ft and back several times, no real distance flying.

I opened the P3A up and ran a + and - cable (XT60) to the mainboard leads. Batteries are mounted underneath the VPS module (turned off).

Single de-shelled DJi OEM battery (4s LiHV 4480mah)
100% battery to 50% - 17minutes 15 seconds. The craft handled just fine without issue, as expected

2x new de-shelled PowerExtra aftermarket P3 batteries (2x 4s in Parallel 8960mah)
100% battery to 51% - 20 minutes 29 seconds. The craft handled poorly but controllable if you pay close attention. The wind was an absolute bear. I kept the P3 pointed directly into the wind and never put her nose with the wind. Heavier batteries like that along with the crazy wind and I believe I would risk the craft backflipping when it came to a braking stop.

Here are a few observations I made that I didn't realize when dealing with that heavier offset rear weight and such high wind.

1) Arming the motors in a strong wind (pointed directly into) can cause the P3 to rock backwards when the motors pulse right after arming. My P3 did not hit but after this happened once, even without an external battery, I paid attention and was quick on the forward stick even when it was on the ground to catch it from tilting back and having the rear props hit the ground.

2) Braking sensitivity in the GO app matters in heavy wind especially with external batteries. I told myself with the larger battery on there I would adjust the braking all the way down to avoid sudden braking stops and a backflip. Well in the wind even in GPS mode this affects the P3's ability to hold GPS position. The P3 will drift with the wind if this is too low and wind is too high. Once I realized this I watched it drift at the lowest setting then hold steady at the highest setting as I dialed it up in flight realtime. This was news to me and a bit shocking. I had the P3 out there a ways and looked down for a minute to check data. I looked up and the thing was drifting with the wind, I couldn't believe it. No it was not in ATTI mode it was still in GPS. Glad I know this now.

3) Heavy weight in high winds means the P3 is harder to control even in GPS mode. When moving it will drift and jerk trying to maintain level. It can be surprising. My advice is to stay in GPS mode and make short moves then hands off the sticks to let the P3 stop and GPS hold (braking of course adjusted as noted above). Making longer movements means it's effectively out of GPS lock and is susceptible to drift and the natural jerking back and forth in the wind as the craft tries to stay somewhat level.

In hindsight today was probably not a good day to fly period much less with external battery loads. I'll have to go out again sometime this week or next weekend and hope the wind is under 10mph instead of 20-30mph+. It looks like the 8960mah external battery performed not as good as expected, only ~4 minutes more of flight time. But I'm not sure I'd call this a valid test. It was so windy I was mostly hovering with that battery as opposed to flying out 1500ft and back and in circles with the smaller battery. I would hope the larger battery would get 7 minutes more than the smaller battery under ideal conditions.

Hey phantom sorry but I have to laugh a little as I've gone through everything you mentioned and I thought I was going to lose the bird a few times to the wind and i know how it feels..Without the brakes on and a heavyass battery hangin in the back its easy to do. Before that almost flippin it with too much brake..Controlling that in heavy winds is almost impossible but its hard to wait for nice weather to test your work...It really sounds like you handled it well. That's why I started to split batteries and hangin them on the sides. Not sayin I wouldn't use a single but I prefer either a split or 2 batteries to balance it out a little..It gives you better control and you can turn up the brakes a little...Or if you do what some did here to move the battery forward, closer to the middle..

One thing I did notice about your batt is that the cells are very exposed..If you read back in this thread you will see I had the same issues until I insulated them...All that covering material over the battery that you took off to save weight is there for a purpose..I think it's more or less a heat-sink... I like what your doing and keep us posted please...

 

[chazz]

Sorry for being a bit off topic here, but as you guys are into battery mods and therefore have good knowledge on battery charges as well, I have a real simplistic question. When comparing two battery chargers both capable of 1C charging rate for a battery in question. What's the difference in one being a higher wattage charger than the other? So for sake of argument let's say the battery is 3000 so my charge rate would be set to three amps. So what's the advantage of having a higher wattage charger if the lower wattage charger is capable of the same amperage output that you're going to use.

I would say same current at less voltage would be slower...Not really sure but the phantom chargers come in 2 different wattage's and the lesser one is slower..

 

[Phantom751874]

Battery mods? Moving camera forward has made more room now both batteries fit and better CG.by flipping the cam mount 180 and cam wire is long enough to do this mod.getting it ready look out pablo here i come.

Hmm, my v1 Advanced cable is not long enough.

 

[chazz]

I would say I found a pretty good setup following Digdat0's lead with a camera mod and 2 - MS5200's...I wouldn't say I flew efficiently at all and still got pretty good numbers…Flying at high elevations to clear mountains and keep signal and then when I came back to finish the battery I flew in circles in the radius of about a mile or so...If I could only find a flat place for 14 miles.


The first pic is 30min to 50% and if I can call any of this flight efficient this would have been where that ends. The second is 46min to 10%... I'll post pics of the bird a little later...

 

[Silverwingflinx]

I would say I found a pretty good setup following Digit0's lead with a camera mod and 2 - MS5200's...I wouldn't say I flew efficiently at all and still got pretty good numbers…Flying at high elevations to clear mountains and keep signal and then when I came back to finish the battery I flew in circles in the radius of about a mile or so...If I could only find a flat place for 14 miles.


The first pic is 30min to 50% and if I can call any of this flight efficient this would have been where that ends. The second is 46min to 10%... I'll post pics of the bird a little later...

hi chazz yes pics of ur set up!!! how many charges on p3 batt? in this amazing flite

 

[Phantom751874]

I would say I found a pretty good setup following Digit0's lead with a camera mod and 2 - MS5200's...I wouldn't say I flew efficiently at all and still got pretty good numbers…Flying at high elevations to clear mountains and keep signal and then when I came back to finish the battery I flew in circles in the radius of about a mile or so...If I could only find a flat place for 14 miles.


The first pic is 30min to 50% and if I can call any of this flight efficient this would have been where that ends. The second is 46min to 10%... I'll post pics of the bird a little later...

Dang 46 minutes.

 

[HWCM]

I would say I found a pretty good setup following Digit0's lead with a camera mod and 2 - MS5200's...I wouldn't say I flew efficiently at all and still got pretty good numbers…Flying at high elevations to clear mountains and keep signal and then when I came back to finish the battery I flew in circles in the radius of about a mile or so...If I could only find a flat place for 14 miles.


The first pic is 30min to 50% and if I can call any of this flight efficient this would have been where that ends. The second is 46min to 10%... I'll post pics of the bird a little later...

****, you flew for 46 minutes? Impressive.

 

[Silverwingflinx]

Dang 46 minutes.

46 mins down to 10% and still a little in the tank!!

 

[chazz]

Yeah you have to be willin to chop up the bird a little...And for some reason i get a gimble error 2029 grams total...

 

[Silverwingflinx]

Yeah you have to be willin to chop up the bird a little...And for some reason i get a gimble error 2029 grams total...View attachment 80519 View attachment 80520 View attachment 80521 View attachment 80522 View attachment 80523

thats a good set up for those batts CG looks good!!

 

[Chris berd]

Everything is fine, and smooth flying

 

[Silverwingflinx]

Everything is fine, and smooth flying

whats the fly time with ur set up!!

 

[Chris berd]

whats the fly time with ur set up!!

25-28min. But my set up was very loaded, i put some 6modes led strobe light,gimbal protector,and reinfocerment plates, maybe it goes beyond 30min.

 

[Phantom751874]

Yeah you have to be willin to chop up the bird a little...And for some reason i get a gimble error 2029 grams total...View attachment 80519 View attachment 80520 View attachment 80521 View attachment 80522 View attachment 80523

Dang son. "It's alive!"

 

[Lee SK]

Yeah you have to be willin to chop up the bird a little...And for some reason i get a gimble error 2029 grams total...View attachment 80519 View attachment 80520 View attachment 80521 View attachment 80522 View attachment 80523

Could I see the power-connected pictures?

 

[Digdat0]

Hmm, my v1 Advanced cable is not long enough.

i think i have an extra one if you want it, pm me your address (and if your in the US?) i'll drop it in the mail.

I would say I found a pretty good setup following Digdat0's lead with a camera mod and 2 - MS5200's...I wouldn't say I flew efficiently at all and still got pretty good numbers…Flying at high elevations to clear mountains and keep signal and then when I came back to finish the battery I flew in circles in the radius of about a mile or so...If I could only find a flat place for 14 miles. The first pic is 30min to 50% and if I can call any of this flight efficient this would have been where that ends. The second is 46min to 10%... I'll post pics of the bird a little later...

chazz, dang man! thats a heck of a flight, 46min to 10% is amazing I think you would get better results in a straight line. Thats easily a 70k flight with the modcam and good conditions. A guy on FB is flying 2x5200 lihv and no cam and he hit 75k recently. I'm getting close/similar to that with the 5200+6600 wrapped like baked potatoes, I think i may need to pickup another 5200 and run two of those!

 

[chazz]

Could I see the power-connected pictures?

Hey Lee do you mean you want to see the batteries plugged in? if so i just changed my bottom shell last night and i took out the lead going to the main board that runs through the leg so i cant show you this but i marked them on the pic where I plugged them in...A to A and B to B...
The new way I'm going to try is like you see in the bottom pic with the parallel lead connecting the two batts. If this doesn't work and drains the batteries unevenly because of added resistance i will add the lead to the main board again...I'm waiting for Dual Lock to come in to attach the batteries is why they're not attached....

 

[chazz]

Yeah Dig the 5200's are a good batt and not too expensive...I'm lookin for a 10000lihv if you ever see one...I have to find a spot where i can keep a low altitude and rubber band the stick to stay straight... I'm always trien to steer between the mts........

 

[Lee SK]

Hey Lee do you mean you want to see the batteries plugged in? if so i just changed my bottom shell last night and i took out the lead going to the main board that runs through the leg so i cant show you this but i marked them on the pic where I plugged them in...A to A and B to B...
The new way I'm going to try is like you see in the bottom pic with the parallel lead connecting the two batts. If this doesn't work and drains the batteries unevenly because of added resistance i will add the lead to the main board again...I'm waiting for Dual Lock to come in to attach the batteries is why they're not attached.... View attachment 80694 View attachment 80695

I easily understand with your pic & explanation
Thanks chazz ^^