zagi 400x amp/watts readings on stock with 1700mah?

Calling all zagi/former zagi owners out there:

I'm just checking things to see if these numbers line up.. to me they seemed alittle shy of what I would expect..

A fully charged 1700mah battery pack reads 11.54 volts on my voltmeter.

I put that connected to an asto whattmeter on the zagi (stock 400 motor with 15 amp esc).. I get 13.82 amps at 120 watts.. voltage on this meter is showing 8.72v..

Ive tested the rpm previously (not this time), i think it rang in around 13K or so..

On my other zagi 400 (not 400x, the one with 400 speed motor, 14 amp esc etc).. with the 500mah battery pack.. I read 11.06 volts fully charged with my seperate meter.. Then on the wattmeter I get 12.16 amps, 95 watts on this one

Do these values seem in line...

Thanks

Reply to
markm75
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| Calling all zagi/former zagi owners out there: | | I'm just checking things to see if these numbers line up.. to me they | seemed alittle shy of what I would expect..

They seem about right to me.

Also, remember that you're looking at static values. In flight, current will drop and voltage will increase.

| I put that connected to an asto whattmeter on the zagi (stock 400 | motor with 15 amp esc).. I get 13.82 amps at 120 watts.. voltage on | this meter is showing 8.72v..

That voltage drop that you see is due to the internal resistance of the battery. Since you're losing about 3.5 volts at 14 amps, that works out to 3.5 volts * 14 amps = 49 watts heating up your battery. No wonder it gets hot!

(Though the amperage and voltage drop will drop in flight, so the energy wasted to heat in the battery will drop as well.)

13.8 amps is really close to the maximum of 15 amps ... so be careful with long term testing on the ground

| On my other zagi 400 (not 400x, the one with 400 speed motor, 14 amp | esc etc).. with the 500mah battery pack.. I read 11.06 volts fully | charged with my seperate meter.. | Then on the wattmeter I get 12.16 amps, 95 watts on this one | | Do these values seem in line...

Yes.

Reply to
Doug McLaren

Thanks for the help.. just wanted to make sure b4 i try to sell these :)

After flying the twinstarII, the zagi feels like a brick to me.. I guess in the case of the zagi the whole, generic 100watts per lb for fun flight holds true.. as it could use more power to be a little more versatile. (the 400x is about 27.1oz)

I'm going to opt for an F27C at some point, rather than upgrading the Zagi, but I now have a fairly good grasp on these things compared to previously.

Thanks for all the help along the way.

Reply to
markm75

At 13A a speed 400 is about 40% efficient anyway.

Bear that in minds.

Reply to
The Natural Philosopher

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