I need help determining which formula is correct when calculating Amp/hrs. needed for a AC device plugged into a 12v. inverter.
Example: Assume 900W AC Coffee Maker run for 10 minutes.
(Minutes / 60) x Watts = Watt/Hrs.
(10/60) x 900 = 150 watt/hrs.
To convert to Amp/hr is where I’m confused. I located this “calculator” online that indicates the formula would be amp/hrs = watt/hrs / AC voltage or
150 /120 = 1.25 amp hours drain on 12v battery
http://dimensions.sensata.com/calculator
This Chart indicates that to find Amp/hrs. you divide Watt/hrs. by DC voltage or
150/12 = 12.5 amp/hrs. drain on Battery.
http://www.all-battery.com/inverterfaq.aspx
I realize there are also some inefficiencies that would need to be factored in to the equation as well, but right now I'm trying to figure out which base formula to start with.
Thanks for any assistance.
Example: Assume 900W AC Coffee Maker run for 10 minutes.
(Minutes / 60) x Watts = Watt/Hrs.
(10/60) x 900 = 150 watt/hrs.
To convert to Amp/hr is where I’m confused. I located this “calculator” online that indicates the formula would be amp/hrs = watt/hrs / AC voltage or
150 /120 = 1.25 amp hours drain on 12v battery
http://dimensions.sensata.com/calculator
This Chart indicates that to find Amp/hrs. you divide Watt/hrs. by DC voltage or
150/12 = 12.5 amp/hrs. drain on Battery.
http://www.all-battery.com/inverterfaq.aspx
I realize there are also some inefficiencies that would need to be factored in to the equation as well, but right now I'm trying to figure out which base formula to start with.
Thanks for any assistance.
