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Confusion about batteries?

Tags:
  • Battery
  • Formula
  • Tablets
Last response: in Other Consumer Electronics
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October 11, 2014 4:10:29 AM

Hoping for help with my calculations.
So my tablet has a 10 hour battery life.

With the info in this link...

http://www.batterymart.com/p-tlp-020-amazon-kindle-fire...

and using this formula...

http://www.rapidtables.com/convert/electric/mah-to-wh.h...

I get 3.7*4550/1000= about 16.8 watt hours
then using this formula...

http://www.rapidtables.com/convert/electric/wh-to-watt....

16.8/10 hour battery life = 1.68 watts

my psu is rated 650 watts, which would mean my desktop uses 500X as much power as my tablet?

What is my error?

Thanks in advance.

More about : confusion batteries

October 11, 2014 4:14:45 AM

No. Your desktop probably averages using 200W. So 150 x.
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October 11, 2014 4:21:10 AM

Don't confuse the power supply Max rating with the actual power consumption. Think of your car, you don't always have the "pedal to the metal" - you use as much power as you need.
-Bruce
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October 11, 2014 4:24:24 AM

i7Baby said:
No. Your desktop probably averages using 200W. So 150 x.


So, it actually uses over a hundred times as much power?
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October 11, 2014 4:25:26 AM

You are trying to compare the power usage of your desktop vs. your tablet? Why?

The idle/average/load power usage of your desktop varies greatly depending on the components in it.

Your PSU rating is only a rough guage of the max power it can provide for your PC. It does not mean it is using 650W all the time.
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October 11, 2014 4:33:44 AM

huilun02 said:
You are trying to compare the power usage of your desktop vs. your tablet? Why?



To test the math, which was vastly different than I would have thought. I was actually in the middle of attempting to look into a mobile desktop.
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October 11, 2014 2:20:34 PM

That runs on battery? As you can see, an ordinary PC will chew through juice. Laptops have low power cpu's an gpu's in them to be able to have good battery run time.

For a mobile desktop, you need to tote a car battery or use low power components. Which means not so high performance.
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