Power inverter question

[Jimbee]

Hey All,

Silly question regarding power inverter battery consumption. If I'm using my portable 400 watt power inverter to power a 75 watt TV, does the inverter draw the full rated wattage at all times or will it only draw the amount of power it needs to run the TV? I have 300 watts of solar to re-charge the batteries during the day, but it would be nice to watch TV at night for a few hours without worrying about draining the batteries too much.

Thanks!

[Lwiddis]

“but it would be nice to watch TV at night for a few hours without worrying about draining the batteries too much”

Do you have an adequate battery bank for your power needs? Determine this by an “what I want to use” energy survey. Once the battery power needed is pegged you can compute if 300 solar watts is sufficient for recharging.

[pianotuna]

Divide wattage of device by 10 to know the battery draw in amps.

75 watts = 7.5 amps.

[time2roll]

The inverter will add about 20% to the tv load.

[Jimbee]

Many Thanks,
I was hoping that the load dictated the power consumption rather than the inverter pulling maximum wattage all the time whether I used it or not!

Jimbee

[jkwilson]

Input power consumed roughly tracks output power being delivered. Depending on the particular inverter, there is some inefficiency. Up to about 15%, so you’d expect maybe 85W being consumed running a 75W load. There is also a small idle demand, probably about 100mA or a Watt to a Watt and a half.