I often see questions surrounding inverter size and battery capacity on the boards, and being that I just had a Xantrex panel installed that can display the amount of Amps flowing out of my batteries; I thought I would measure the power consumption of various devices in hopes of answering some of those questions. I recommend Mark Nemeth’s “The 12 volt side of life Part 1” and “The 12 volt side of life Part 2” to anyone who is interested in their RV’s electrical system. Mark’s articles are refreshingly clear, concise and easy to understand.
Alright, we might as well start with the big dog! This is my 1,100 Watt Dometic microwave oven. It is easy to calculate the power consumption of a device by looking at the electrical plate near the power cord, or on the power brick. Dometic says the “rated power consumption” for this microwave is 1,500W. It is not uncommon for a device to consume more power, particularly at initial turn-on, than you might think without first checking the device’s electrical specifications.
1,500 Watts of AC power is about 150 Amps of DC power, which is why the inverter manufacturers always specify big cables for the larger inverters – 150 Amps is a lot of current. After putting a cup of water into the microwave and selecting maximum power, my panel measured 158 Amps proving, if nothing else, that some of this theory must be grounded in reality. Here are a few other gadgets that I measured:
- Satellite TV receiver: 3 Amps
- 20” HDTV: 7 Amps
- 17” LCD TV: 5 Amps
- Laptop computer: 5 Amps
- DVD player: 3 Amps
- Mobile phone charger: 2 Amps
Happy camping!