Re: Voltage Vs. Current In A Laptop Battery?

From	"Anthony R. Gold" <not-for-mail@ahjg.co.uk>
Newsgroups	comp.sys.laptops
Subject	Re: Voltage Vs. Current In A Laptop Battery?
Date	2012-04-08 22:13 +0100
Organization	Microvest Limited, London
Message-ID	<icv3o7h3tdrmlutarfi6rtlt8f46u94541@4ax.com> (permalink)
References	(4 earlier) <mbu0o7pie58j6u15vsorbob5433tvo8krn@4ax.com> <1b91o7tm50st04qvkstkvmnvvhe0pcc4ot@4ax.com> <g193o7p7v7g8btfqcpumeu7g530jqh741b@4ax.com> <n6h3o7d6r33gdj2oed803kraidamesf3se@4ax.com> <ppj3o71ovnocoge6p2hv8g4vtgdqhv0nk4@4ax.com>

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On Sun, 08 Apr 2012 20:48:49 +0300, Happy Oyster <*@*.*> wrote:

> On Sun, 08 Apr 2012 18:23:39 +0100, "Anthony R. Gold"
> <not-for-mail@ahjg.co.uk> wrote:
>
>> The definition of 1 watt (W) = 1 joule per second (J/s).
>>
>> It is also equal to V.A (i.e the scalar product of potential difference and
>> current, so VA only when the phase angle is zero) and equal to kg.m^2.s^-3.
>
>
> <quote>
> Watt definition
>
> Watt is the unit of power (symbol: W).
>
> The watt unit is named after James Watt, the inventor of the steam
> engine.
>
> One watt is defined as the energy consumption rate of one joule per
> second.
>
> 1W = 1J / 1s
>
> One watt is also defined as the current flow of one ampere with voltage
> of one volt.
>
> 1W = 1V × 1A

Whoa there, two different definitions for one SI unit? That is unbelievable
(in the literal sense of that word)!

> </quote>
>
> source:
> http://www.rapidtables.com/electric/watt.htm#definition

Thanks, but WTF are rapidtables and what is their authority to define
anything?

A derived SI unit is formally defined in terms of SI base units and the
definition of the watt is kg.m^2.s^-3.

Ref:
http://physics.nist.gov/cuu/pdf/sp811.pdf
http://physics.nist.gov/cuu/Units/units.html
http://www.french-metrology.com/en/si/units-measurement.asp#derivees

For an explanation of the difference between VA and V.A (i.e. between the
product of their magnitudes and their scalar product) try:
http://www.google.co.uk/#hl=en&sclient=psy-ab&q=difference+between+power+and+VA&oq=difference+between+power+and+VA&aq=f&aqi=q-w1&aql=1&gs_l=hp.3..33i21.1508l11545l0l12805l31l11l0l20l20l0l376l1503l4j5j1j1l31l0.efis.1.&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=277d1bcc24ee76c4&biw=1024&bih=570
and take your pick amongst the hundreds of hits.

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Thread

Voltage Vs. Current In A Laptop Battery? Ron <orion@dslnorthwest.net> - 2012-03-28 12:05 -0700
  Re: Voltage Vs. Current In A Laptop Battery? Bob_Villa <pheeh.zero@gmail.com> - 2012-03-28 15:57 -0700
    Re: Voltage Vs. Current In A Laptop Battery? Ron <orion@dslnorthwest.net> - 2012-03-28 19:18 -0700
      Re: Voltage Vs. Current In A Laptop Battery? Bob_Villa <pheeh.zero@gmail.com> - 2012-03-29 02:52 -0700
  Re: Voltage Vs. Current In A Laptop Battery? "BillW50" <BillW50@aol.kom> - 2012-04-02 15:41 -0500
    Re: Voltage Vs. Current In A Laptop Battery? Bob_Villa <pheeh.zero@gmail.com> - 2012-04-02 16:37 -0700
      Re: Voltage Vs. Current In A Laptop Battery? "RnR" <rnrtexas@gmail.com> - 2012-04-12 21:59 -0500
    Re: Voltage Vs. Current In A Laptop Battery? Ron <orion@dslnorthwest.net> - 2012-04-05 12:53 -0700
      Re: Voltage Vs. Current In A Laptop Battery? "BillW50" <BillW50@aol.kom> - 2012-04-05 15:12 -0500
        Re: Voltage Vs. Current In A Laptop Battery? wrat@panix.com (the wharf rat) - 2012-04-06 23:33 +0000
          Re: Voltage Vs. Current In A Laptop Battery? "BillW50" <BillW50@aol.kom> - 2012-04-06 18:50 -0500
            Re: Voltage Vs. Current In A Laptop Battery? Ron <orion@dslnorthwest.net> - 2012-04-07 16:34 -0700
      Re: Voltage Vs. Current In A Laptop Battery? "Anthony R. Gold" <not-for-mail@ahjg.co.uk> - 2012-04-07 17:53 +0100
        Re: Voltage Vs. Current In A Laptop Battery? richgr@panix.com (Rich Greenberg) - 2012-04-07 18:28 +0000
        Re: Voltage Vs. Current In A Laptop Battery? "BillW50" <BillW50@aol.kom> - 2012-04-07 13:33 -0500
          Re: Voltage Vs. Current In A Laptop Battery? "Anthony R. Gold" <not-for-mail@ahjg.co.uk> - 2012-04-07 19:43 +0100
          Re: Voltage Vs. Current In A Laptop Battery? wrat@panix.com (the wharf rat) - 2012-04-08 10:20 +0000
            Re: Voltage Vs. Current In A Laptop Battery? Happy Oyster <*@*.*> - 2012-04-08 17:52 +0300
        Re: Voltage Vs. Current In A Laptop Battery? Happy Oyster <*@*.*> - 2012-04-07 20:37 +0300
          Re: Voltage Vs. Current In A Laptop Battery? "Anthony R. Gold" <not-for-mail@ahjg.co.uk> - 2012-04-07 21:43 +0100
            Re: Voltage Vs. Current In A Laptop Battery? Happy Oyster <*@*.*> - 2012-04-08 17:47 +0300
              Re: Voltage Vs. Current In A Laptop Battery? "Anthony R. Gold" <not-for-mail@ahjg.co.uk> - 2012-04-08 18:23 +0100
                Re: Voltage Vs. Current In A Laptop Battery? Happy Oyster <*@*.*> - 2012-04-08 20:48 +0300
                Re: Voltage Vs. Current In A Laptop Battery? "Anthony R. Gold" <not-for-mail@ahjg.co.uk> - 2012-04-08 22:13 +0100

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