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Topic: Arduino Uno Standalone Power (Read 1 time) previous topic - next topic

trendski

Hi,

I'm new to Arduino. Had an Arduino Uno (with Atmel ATMEGA328P-PU) about a week now. Does anyone know how much power the Uno uses on it's own with no project attached to it?
Does it depend on the power supply  - I want to use a good quality 9v battery I wonder how long it will power the standalone board for even before I add stuff?

Cheers
Craig Turner, blog: http://gampageek.blogspot.co.uk/ It helps with my learning if I write things down, esp. for others to follow (constructive comments welcomed to improve)

Grumpy_Mike

It takes about 30mA at 5V so the power is 0.15W. But do you mean power because you also have to calculate what the regulator takes.

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I want to use a good quality 9v battery

Bit of an oxymoron, I don't think they exist.

trendski

Thanks for the tip.

Would it be better to use 2x 3.7v mobile phone batteries I have (1400 mAh each) to give 7.4v?

I think I should mean current as opposed to power so I can do: mAh / Uno_board_ current_consumption (including regulator)

Would the regulator use a lot at 7.4v?

Craig Turner, blog: http://gampageek.blogspot.co.uk/ It helps with my learning if I write things down, esp. for others to follow (constructive comments welcomed to improve)

Grumpy_Mike

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Would it be better to use 2x 3.7v mobile phone batteries

Yes defiantly.

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Would the regulator use a lot at 7.4v?

Not sure what you mean. A regulator drops the voltage from the input down to (in this case) 5V. It needs a few volts at the input over the final regulated voltage to work. So changing that input voltage from 9V to 7.4V will make the system more efficient as the regulator has less power to burn off in the form of heat.
Take a look at this:-
http://www.thebox.myzen.co.uk/Tutorial/Power.html

liudr

There are switching voltage regulators that waste less power when converting from a higher voltage to 5V. I'm not sure what part number. I'm saying this just to ring a bell to those that do know a part number or two. There could be a part that has the same size as the UNO's regulator and you can replace it with the switching supply for your project to last longer.

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