6600mAh Stealth Battery Mod ... (27.5 minute flight times)

[DBS]

Here I go again with one of my pain in the *** mods

The Task at Hand

#1) Get more flight time....
#2) Don't mess up the look of the Phantom...
#3) Don't add more weight....
#4) Don't f@#% this up!!! :|



Research first...

Find a battery with more power... sized fairly decent to still squeeze in the battery bay... and not too heavy...

Ended up with this 6600mAh deal that was made for the Blade QR-X350 Pro ... measurements looked ok... weight looked good...
Took the plunge and ordered a couple.... http://r.ebay.com/Y3q984



Next thing... was to tear apart a DJI Battery and figure out the wiring specifics...
That wasn't so bad... shoulda waited till the other batteries showed up from China... Ended up stuck with just one battery for a couple weeks there

The battery is pretty straight forward... Two PC boards... top one is the smart one doing all the work... bottom one is just a router bringing all the cells together and sending power and data to the quick connectors... A simple six wire flat cable uses four wires for balance leads and two wires to send data to the infamous spring pads on the battery quick connect hub... The two fat black wires are the switched negative to turn the Phantom on and off... Positive is always connected when the battery is installed...

My plan was to ditch all that "quick connect spring pin ****" ... and go with solid Deans Connectors and solder data wires direct ... I wanted solid... I wanted dependable... and I wanted MORE :twisted:




Snip Snip Clip Clip....

Got the main smart board removed from the battery and started working out a location for permanent mounting... This required a complete teardown... didn't really wanna do it... but then again... wanted to do it right... so there it went... gutted that baby

Inside the battery bay I found a good spot...

For my long range setup I have moved the stock DJI antennas outside the hull anyway... boom... done ... snipped out some plastic ribs that held the antenna and it fits like a charm... weird... like it belongs there

Got it all cemented in place and JST connector soldered and shrunk to the 4 "smart wires"...
ground main soldered and shrunk and layed out...

Moving on...

With that I could start reassembly ... solder in positive main... solder in negative switched main... solder and shrink data wires...
And start finishing things up with this little bad boy....

View from the battery door shows why I wanted to hide all this crap...

Next was cleanup...

Solder and shrink Deans Connectors... Hollow out battery cover and glue power button back in place for that "stock" look...
Contact cement and some shaped EPP foam to make the battery sit tight in the bay...
Slide a battery in the bay and plug everything in and cross my fingers...

pro-tip ... always plug the mains in first... then the JST connector




And That's a Wrap...

Snap things together and wait for decent weather to test fly...
(which happened tonight btw... Screenshot at bottom of post)

And you can't even tell it's there...

First test...

First charge on this battery...
First flight jitters hoping it would work out ok....
Just landed a little while ago and snapped a Screenshot... started video record right after I took off and Screenshot right after I landed so this is pretty **** accurate... and I didn't baby the thing and just hover the whole time... I flew around quite a bit and it was pretty breezy as well... I mean, I wasn't hammering it the whole time but I'm totally stoked with this... it was still light out when I launched this baby!! :twisted:

I figure this will get a bit better too... you know how Lipos are on a first date ... After a few charges and cycles we'll see how she settles in and get a good average of airtime...


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Now **** gets real... going for a new distance record and this battery setup will get me there...




How far can YOU fly???



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[Dirty Bird]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Nice Mod DBS. 25 minutes of flight time! :shock:

I wonder if there is some way you could retain the Smart board with LEDs in the battery cap so you still have the visual power on and power level lights?

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

I deliberately went away from that for a more solid connection inside the body... lights are still visible thru the gills on the side of the bird so I'm all good with this setup...

The way the cap fits it barely squeezes on over the Deans Connectors and main wires so it would be a super tough deal to get the smart board in that same spot :|

 

[tizzl10]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

very cool mod.

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Thanks Tizz ... any luck with finding more range on your side? Haven't seen you post up for awhile now.... I guess the whole range thing has calmed down pretty much... I haven't done much lately either :|

 

[Dirty Bird]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

The green glow through the grill is actually kind of cool...sort of like the light bars they put under cars.

 

[DronePilot]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

DBS: Gotta say I used to be impressed with the things you came up with on the AR drone back in the day The things you've found and come up with on this bird, even more impressive. Nice work! Thanks for the details!

 

[ElGuano]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

REALLY nicely done. Hats off to you!

The last (first?) person who did this reported that the SMB board was set to 5200mah for the stock battery, and a bigger battery would exceed the max capacity set in the firmware. Did you run into that or have to do anything to bypass it?

 

[M.Tigelaar]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Well done,
what is the extra weight?

 

[ToThePoint]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Nice Mod DBS. 25 minutes of flight time! :shock:

I wonder if there is some way you could retain the Smart board with LEDs in the battery cap so you still have the visual power on and power level lights?

It could be done DB but i don't agree with that point of view.
How many times do you check your battery status true the leds ?
First of all the bird must hover in front of you.
When its some short distance away the leds indicator isn't that obvious anymore.
What i see in the app is sufficient enough i guess.

@DBS

Nice mod and a way i would do it.
Waiting for good calm conditions.
Accepting the challange.
Fly safe DBS !

 

[slothead]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Here I go again with one of my pain in the *** mods

Thanks for this detail of the new mod. My question to you: Is this new battery constructed as well as the DJI battery (which design deficiencies you explained in a recent post)? It seems that for a 3S battery at 6.6AHr capacity, it would have to be?

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

REALLY nicely done. Hats off to you!

The last (first?) person who did this reported that the SMB board was set to 5200mah for the stock battery, and a bigger battery would exceed the max capacity set in the firmware. Did you run into that or have to do anything to bypass it?

I have a little different explanation for that... The larger battery doesn't exceed the firmware... it works just fine... BUT ... The Smart board is still calibrated for the 5200mAh battery and it will throw off the curve on the app battery percentage display...

In other words...

I went out and flew this first battery yesterday... for the first 18 minutes I was totally disappointed.... everything was the same as a stock DJI Battery. .. 50% was reached at 8:30... 25% at 13:00... and then 8% at just under 18 minutes... then it got stuck at 8% for a full 6 minutes and kept hovering with some added stick to keep it up... that is the calibration point that DJI talks about in their user manual... "every 20 flights fly the battery down under 8% or until it doesn't turn on any longer" ... THAT recalibrates the gauge to the bottom end of the battery and gives you more accurate curve on the gauge as you fly... so as I fly these new batteries the first few times the firmware will "learn" where the bottom of the battery is and give me a more accurate readout of where I'm at percentage wise during the flight.

Everybody that says "don't fly your batteries that low or you will risk damage" is totally wrong... The phantom has an automatic cutoff at 10.4volts to save the battery from damaging itself... that 10.4volts is 0% on the gauge... totally safe to fly all the way to zero... AND if you're not doing that you are not getting the most out of your battery.

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Well done,
what is the extra weight?

New battery weighs in at 375 grams... I didn't weigh my stock batteries but I've heard they're around that same weight with the case... I weighed the one I was working on after it was taken apart and the smart board removed and it was only 325grams with just the cells and the solder board still attached.

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Here I go again with one of my pain in the *** mods

Thanks for this detail of the new mod. My question to you: Is this new battery constructed as well as the DJI battery (which design deficiencies you explained in a recent post)? It seems that for a 3S battery at 6.6AHr capacity, it would have to be?

No good news on this one bro... same 6 cell design with cells in parallel to make the 3 cell design... couldn't get away from that if I wanted a battery to fit inside the battery bay without modification to the phantom body...

Good news is they are cheaper... and I can keep them healthier with my accucell charger using 1 amp cycles and balancing along the way...

Still don't think this is the best design but knowing what you have and how to deal with it helps quite a bit... it's the lesser of two evils right now and I had to make the choice :twisted:

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Nice mod and a way i would do it.
Waiting for good calm conditions.
Accepting the challange.
Fly safe DBS !

Thanks TTP....

Woke up this morning and could hear the wind outside before I got out of bed

Like you said ... fly safe ... there's always another day ... The waiting game begins :twisted:

 

[mede8er]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Well done,
what is the extra weight?

New battery weighs in at 375 grams... I didn't weigh my stock batteries but I've heard they're around that same weight with the case... I weighed the one I was working on after it was taken apart and the smart board removed and it was only 325grams with just the cells and the solder board still attached.

Can confirm...my 3 stock batteries weigh in at 360, 361, 360...15 grams for 5+ minutes??? I'll make that trade in a heartbeat...

Outstanding work Chuck...

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Can confirm...my 3 stock batteries weigh in at 360, 361, 360...15 grams for 5+ minutes??? I'll make that trade in a heartbeat...

Outstanding work Chuck...

Thankyou sir... just weighed all mine too... 2 new 6600mAh batteries come in at 373 and 371... The other DJI stock battery I have left over shows 366...

Total weight for this mod is a bit higher because I use the smart board from a stock battery ... Hot glue to hold everything rock solid ... a few inches of fat wire and a Deans Connector on the phantom side for mains ... a JST connector with a few inches of cable for that as well... and the battery cap to close the bay for flight.

Still probly only a gain of 30/35 grams total I imagine :ugeek:

 

[ilovecoffee]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Hey DBS,

I'm definitely going to be doing this when a battery gives out (inevitably)

Quick Q: Doesn't the Phantom instruct itself to auto land at a certain percentage? Wasn't it 15%?

I'm wondering if it will keep displaying that 8% pause with you, or whether or not it will correct itself. If not, maybe it has something to do with the app that I can fix/adjust.

 

[DBS]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

DBS: Gotta say I used to be impressed with the things you came up with on the AR drone back in the day The things you've found and come up with on this bird, even more impressive. Nice work! Thanks for the details!

THANKS DP!!

feels like we been around forever huh??

Kinda miss hacking on that old AR

 

[ilovecoffee]

Re: 6600mAh Stealth Battery Mod ... (25 minute flight times)

Is the Walkera battery also made up of 3 cells? (answered my own question: yes) I'm wondering if it's just possible to do a straight switch within the same DJI battery frame.

I've seen some 10,000 mah 11.1v batteries but they are over 650grams and I doubt the size will fit. But there is this 7800mah which isn't far off at 526g.

http://www.thunderpowerrc.com/Products/ ... 800-3SPP25

Would be nice to find comparable actual cells in a similar size that we could cut into a somewhat modified original battery.