G.F. Reid

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Ok, don't laugh...I know next to nothing about e-flight power systems.
I have an old Soarstar at home and I'm wondering what options I have on replacing the old original 9.6 NiCad. Can I use a Lipo...say an 11.1v 3s pack without having to change the speed controller and motor? How about a NiMh pack?
In short, what are the options?

blvdbuzzard

NIMH should be a drop in, 3s LIPO, umm, does the old ESC handle them? That old ESC may not have the voltage cut off a lipo would need. If it is a BL motor, a new ESC and lipo would be cheap enough.

Buzz.

G.F. Reid

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Thank Buzz. That's just the kind of info I was looking for. I'm going to try the Nimh since the Parkzone Mustang they came out of is 'resting in pieces'. I doubt the esc was set up for LiPo. This plane is old. I've been out of the hobby for 10 years and it's probably 5 or 6 years older than that. I figured this old thing would be good to warm up the thumbs.

blvdbuzzard

A new motor, esc, battery would be cheap enough. You would get more power, longer flights with a new power package.

I looked it up. This might work for you. May have to do a little soldering here and there? Start with an 8x4 prop and see how that does. Might want to pick up a watt meter too. A watt meter will help you to keep the magic smoke in. Once it gets out, nothing works.

Motor.

http://www.valuehobby.com/power-syst...12-1400kv.html

ESC
http://www.valuehobby.com/power-syst...e-20a-esc.html

Battery
http://www.valuehobby.com/power-syst...0mah-3s-t.html

Watt metter
http://www.valuehobby.com/gt-power-130a-wattmeter.html


Buzz.

G.F. Reid

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Wow, thanks Buzz! Way more info than I expected.
As for the Wattmeter, how do I determine what I'm looking for with a particular combination? I see that the ESC is rated in Watts so that's clear. I know the LiPo battery cares about the discharge rate so I think I'm clear on that. How about the motor?
Sorry for all the questions but I'm a glow and gas guy from way back.

blvdbuzzard

You can start with a smaller prop, see how many amps it draws, go up on the prop size, and read how many amps it is drawing so you don't pull more than the ESC, motor or battery can handle. Looking under the specs of the motor, it does not list the max anything. So I looked at another one to get an idea. It said 17 amps for 60 seconds. That would be a close enough. So if you are pulling some where around 10 to 15 amps, give or take a little.

They recommend 2s-4s battery 8X4-8X6 prop. So start with a 3s 6x4 and see what you get. If the watts are down, step up the prop and see what the next one does.

My guess, the motor will run an 8x6 prop on a 2s battery. If you try that with a 4s battery, it may spin it, but not for long.

To me a few extra smaller props is cheaper than letting out that magic smoke

Buzz.

G.F. Reid

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Thanks. I really appreciate the info. I'm not looking to make a major project out of this Soarstar but what I really appreciate is the primer on how to work with e-flight power systems. Very informative!

blvdbuzzard

There really is only one chance to do it right. Do it wrong, instant smoke. I have burned up enough over the years learning how it works. If you get into the big ones, it costs a lot of money if you do it wrong.

When you get it in the air, let us know.


Buzz.

G.F. Reid

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Will do...and thanks again!