If you ONLY upgrade the Battery, do you have to upgrade ESC?

[father&son]

Okay, I've continued to do a lot of reading.  particularly here: supercubclub.proboards.com/index.cgi?action=display&board=batt&thread=1831&page=1 and here: supercubclub.proboards.com/thread/4217.

I posted last week that I'd like to get longer flying times and therefore may upgrade to a 2200mAh 3s battery.  I have no interest (yet) in upgrading the motor/prop/control surfaces etc.

ASSUMING everything else is STOCK, and ASSUMING the dodgy stock ESC performs as it is expected to (let's say it handles an 18.5A draw from the power plant - ref the tests done in the very helpful threads above...),

Does the Battery upgrade alone require an ESC upgrade?  If I understand the basic concepts here, the ESC is a flow limiter, and shouldn't die as long as the demands from the motor/prop don't exceed the maximum current draw for which the ESC is rated -- it limits what the motor can PULL.

But does the current the battery is capable of PUSHING matter to the ESC, as long as the motor isn't PULLING too much?

I ask more to gain an understanding of the physics here.  I recon I'll upgrade the ESC soon anyway as there seems to be very little downside, and a lot of up.

okay, have at it!

[flydiver]

No, you don't have to change it. You might have to go a bit easier on the throttle. A better battery is capable of supplying a bit more power (read link below) and pushing the ESC to the limit since it's probably so close anyway.

Plus...you have it wrong. The ESC is NOT a flow 'limiter'-a common misconception. The motor and the size of the prop and the battery voltage determine the amp draw. The ESC attempts to deliver what the power package asks/demands. If it can, it does. If it can't, it burns up after awhile.

The battery pushes nothing, another wrong concept. It supplies the demands of the motor and prop. Change the prop, the demands change. Smaller prop > less demand. Larger prop > more demand.
Kind of the same with the motor. Put on a small prop, it spins easily and cool. Put on too big a prop and it still tries to turn it at the same speed...but it can't since the load is too great, it gets hot, and it burns up....if the ESC doesn't burn up first. That's why the power train needs to be balanced as a whole.

Try this one:
supercubclub.proboards.com/thread/4624/stock-motor-prop-thread-straight

The downside to upgrading the ESC is the current one is an ESC+RX, so you have to upgrade/replace the RX also. The ESC is BRUSHED and they are getting somewhat rare. Most are made for NiMh batteries so the LVC is too low. That kind of argues for upgrading to a brushless motor+ESC. Thank Horizon, they gotcha. Once you do all of that you may just have well bought a foam blank.

[father&son]

Mar 14, 2014 21:07:31 GMT 1 flydiver said:

That kind of argues for upgrading to a brushless motor+ESC. Thank Horizon, they gotcha. Once you do all of that you may just have well bought a foam blank.

LOL.  It turns out, that I have!  Didn't intend to, but I just couldn't resist this, plus my son is really excited to build it with me.

I did in fact think about the ESC/Rx-combo conundrum, and drew the same conclusion you did.  I think we might just leave the SC stock in honor of its status as our first plane.  We'll build the Spitfire together and outfit it with a nice, balanced, brushless power plant (with a bigger battery) when we're ready to move up to a four-channel aircraft.

Thanks for the reply and the link, as always!

PS:  I think the flight test guys (Especially Josh Bixler and David) demonstrate the BEST of what this hobby has to offer:  Community, service and education.  I have really enjoyed using their site.  Spending a little $$ to pick up the above-referenced kit and support their efforts was a no brainer.

[flydiver]

Warbird. Pretty. Probably fast and hard to fly.....think about that. Going from docile 3-Ch to an aggressive 4-Ch is a big step.
Might be a building stepping stone to try out one of these:

The NutBall, best d**n RET foamy yet..... - www.rcgroups.com/forums/showthread.php?t=836389
Superfly and Superflea clones KFm4 in depron - www.rcgroups.com/forums/showthread.php?t=977954
There are lots of scratch build options.

Building from scratch is a lot different than throwing an RTF together. There are a LOT more things to deal with, ALL the electronics being a major one.

[father&son]

A warbird with undercambered wingtips and a slowlfly prop, designed as an entry-level 4-chan project.

Anyway, I think if you look at the whole project it's a great way to learn about scratch building in a scratch building-lite kind of way.

It will be a long term project. Who knows, perhaps we will build the power pod and then put it into a nutBall first before attempting to fly the Spit. But truthfully, I'm not worried.

[hghost]

All I can say is I have War Birds, both small and very large ones. Flying them is a chore and stressful. Not like the high wing trainers at all.

My issue came when no matter what i did, they kept inverting. ( still mind boggled with that )

The Very Large ones I have not flown due to flying space limitations.

But building a plane is great and a very good learning and growing time. But one has to be aware of what it takes to not only build but to set it up right to fly.
( my mistakes when i first started in the hobby )

To me building is easy, setting them up and getting the system right is another matter.

Of course with today's information and technology easy to obtain, it is not as bad as it once was.

I wish you the best with your endeavors .

[father&son]

Much appreciated hg, truly. Part of being new to any hobby (and no, this is NOT my first) is finding your way at your own pace. Part of being a veteran an any hobby is imparting encouraging guidance, without becoming pedantic or oppressive with the doom-saying. I love this forum for that reason: The sense of community is so palpable.

I very much appreciate Fly's and your advice. What better experience to benefit from than that of those who have been there already -- especially those who were there pre-internet/pre-flight test/pre information BOOM, who TRULY had to find their own way.

...and if the Spit winds up as a pile of useless foam-board, a fried ESC and a puffed LiPo, so be it. The lessons will be invaluable. that which does not kill you...etc, etc. How else does one learn, but by exploration and experimentation (my inner scientist is clamoring to get out, I've kept him bottled up for a while lately)

Onward and upward.