Davethebluessinger

OK this is complicated!
A friend of mine bought a used Walkera QR X350 quad.
It came with a stock 2.2 Lipo
He's now been bitten after watching my Durafly Dynamic S warmliner flying and as they seem to be unavailable has decided to buy the ST Blaze which is an IDENTICAL plane.
He wants to buy some more batteries to fit the Walkera quad so I advised him that a 2.2 lipo will be perfect for the ST Blaze too.
The problem is this, from experience I know in the Blaze that he'll need at least 25C or preferably 30C discharge rating, no issues there as HK have a whole raft of Lipos to fit that bill, however they are all TOO LONG to fit into the quad! The stock battery is only 85mm long all of the branded cells on hobbyking are between 100 and 108mm long.
Is there anyone out there using a non Walkera 2200mah lipo in the QR X350? If so can you tell me what make it is please?
To further complicate matters, the quad came with a spare body shell - from the QR X350 PRO which will house a Walkera 5200mah Lipo but although it's volume is bigger the max length is exactly the same as the standard bodyshell. So if he fits the bigger shell he could buy a 5200mah Lipo for the quad, but that's of no use when it comes to powering the Blaze as 2200mah is as big as it will comfortably hold!
I've searched high and low but can't find any 2200mah batteries that are suitable! HELP!!!
PS if anyone knows of an extended battery door for the QR X350 (like the one sold to fit the phantom) please let me have details!

pizzano

Couple of questions first......

Is this an older standard Walkera QR X350, without GPS and not the Pro version.....?

Is the QR X350 being flown with camera or FPV equipment installed......?

The reason I ask is because the 2200mah 11.1v, 30c battery is the recommended stock application..........guys who are using FPV or AV/AP like on the Pro model, have reported that the 2200mah is a little weak and most have found that anything larger than a 2500mah (5200mah) will not fit without modifications or strapping the larger battery outside of the frame case.......as you have determined.

The greater "C" value (30 to 40) generally does not change the physical size of a 2200mah.......but it is recommended for quad's and heli's that a "C" value of nothing less than 30 be used since the "burst" rate is more critical for multi rotor applications......the mah just provides longer flight duration (required with AV/AP functions)......a 30C should not be an issue with the Blaze either....!

Over at the RcGroup forum, there several threads related to battery applications for the Walkera....... the quick look see I just did mentions Turnigy, E-flite, Hobby People, TicGr, ElectriFly and SkyLipo, all of which are btw. 102mm to 104mm in length and appear to fit just fine in the Walkera QR X350........?......not many user's over there report strapping a 5300mah on that size of quad....?....for all the obvious reasons.

As you stated, HK has several variations of the 2200mah......there should not be an issue finding one size 30C that will fit both craft since 102mm to 104mm seems to be the "standard" size for a 2200mah.......

Davethebluessinger

Hi Pizzano,
The Walkera is a QR X350 not the Pro but it does have GPS.
Yes it will be used with a small board cam for FPV.
We also have a "pro" body shell we could use but again the battery bay is wider and taller but still the same length.
The stock battery is only 85mm long and theres not much extra room in the length of the battery bay to accommodate other longer lipos.
The smallest 2200 mAh Lipo I can find in the UK is the Turnigy Nano Tech at a little over 100mm, I'm toying with the idea that we sling a battery underneath in a home made mount thus solving the size problem and allowing him to buy reasonably priced batteries that will work with the Walkera and the Blaze. We could then remove the door from the battery hatch and insert a block of styrene foam that could have a firewall on the end which we could attach the FPV camera to.
Incidentally, if the C rating for multirotors is so high then how come HK are selling their Multistar range as being recommended for multirotor applications? They have lower weight due to reduced C rating I believe as low as 10C?! Personally I fly 30C or greater Gens Ace and Loong Max Tipples in most of my fixed wings and they have been superb lasting 3 seasons of flight. On my F550 Clone I'm using Turnigy40C 5000 mahs

pizzano

"Incidentally, if the C rating for multirotors is so high then how come HK are selling their Multistar range as being recommended for multirotor applications? They have lower weight due to reduced C rating I believe as low as 10C?!"

Common Dave, we both know truth in advertising, especially from HK, should not be taken seriously......

Unless the vendor provides technical proof, spec's and guarantees/warranties that support their claims, the buyer is left holding the bag full of broken parts without recourse in the event of failure.
I and many other's could reference more than +100 examples of this with HK and other over seas (China) venders when it comes to battery and other electronic equipment....buyer beware and educated is my recommendation.

A reduced/increased "C" value does not always equate to smaller/larger physical size or weight, particularly if the "C" is only + 10.....it's the mAh that has the greatest influence on size/weight.

The reason the "C" value or burst rate is critical on multi-rotor's, heli's ect., in layman's terms, is due to the instant (quicker) demand/response for power required to provide rotor driven craft stability, synchronization and timing.........unlike a plank, multi-rotor's don't fly unless under power and the higher burst rate provides that power quicker.

As for the battery size limitations on the Walkera, I know two flying buddies who used 102mm (length) 2200mAh 30C and 2500mAh 30C with the stock 350 and the 5200mAh batteries on the Pro Deluxe.......all they did was increase the size by modifying the inside of the battery compartment (for the standard 350) and left the wiring connectors outside of the compartment, with the lid installed. The Pro Deluxe comes with the 5200mAh and the compartment has been revised but is a tight fit........you are correct, the 5200mAh will not fit the standard 350......there's no room to increase the compartment for width and depth.
Since they also use FPV/camera set-ups, they chose not to have any additional crap hanging off the frame and cared not to expose the battery for safety reasons.....I'm sure you can do this as well......

Here's a link a buddy gave me for a larger mAh battery that fits the Standard 350...otherwise, you'll need to consider installing the Pro body to fit a 5200mAh.....not a simple task, that's only one reason why my buddies eventually went with the Pro and have since shelved all Walkera models and only fly Blade or DJI for AP/AV/FPV....:

http://www.hobbyking.com/hobbyking/s...arehouse_.html

I believe it's still available and can be purchased from the U.K..........

kenmtb

Valuehobby sells a 2700 battery for the Phantom1 that will just squeeze in to the x350

solentlife

Actually change of C rating does have an effect on weight ... and usually size as well. I agree that mAh rating (capacity ) has greatest effect but C certainly does.

The only time you usually see a same weight or reduced with increased C rating is when seller is basically full of S*** and making false claims. Ebay LiPo's are rife for that where guys get hold of factory seconds or rejects .. then bump up the stated specs to sell.
I've got caught out on it !!

Nigel