California DRE No. 01807002
Now, it's important to do your calculations. Using this example, the vehicle is the power supply creating Direct Current power (DC) to the battery (12 volts). The inverter is a Modified Sine Wave inverter rated at 1,000 watts continuous power. It can supply up to 1,000 watts without interruption. Sometimes items such as a fridge can jump up in power consumption, but then settle back down when first plugged in. Now for the math. Adding up the 172 watt fridge + 80 watt charger for the laptop and two 40 watt light bulbs equals 332 total watts. This is well under 1,000 watts maximum rating for the inverter. Personally, I hook up my heater (natural gas) to the inverter. The blower requires 600 watts and the heater works great. Thus, all together, I’m still under 1,000 watts. However on startup, I will start the heater to warm up the house first, then add the fridge, etc. All these items are plugged in from extension cord(s). The inverter has 2 plugs and one for the heater, and one for the fridge/light bulb.
On a personal note, I use this setup for the morning hours, and the evening hours only. Getting the fridge plugged in while making breakfast and continue to cool down to preserve the food is key. Thus, plug in the fridge in the morning, cook breakfast (gas stove) and let the fridge run even an hour after done to ensure it's cooled enough. After, I turn off the car/inverter. All day, the fridge will be fine, just like all night. No need to run day and night. Lunch time is short, but dinner time, I will run the car again with the fridge for cooking, and then let it run for another one or so hours. Depends on when the fridge stops running, I then know it's cooled down enough. Also, I'll run the heater in the evening to warm up the house. A light bulb so we can play card games or such. Once the house is warmed up, the fridge/freezer is cooled down, then I'll turn off the car/inverter setup for the night. No need to run day and night.
If using a Pure Sine Wave inverter, this can be used for more sensitive electronic items such as a tv, computer, DSL modem (cable modem can be too, but will discuss further in this article) or other items that do not have a battery in between. Remember, the batter acts like a filter, but in a Pure Sine Wave inverter, it is not required, but can still be used such as a laptop, fridge, or just about anything else that will not exceed the rated watts of the inverter.
DSL modems can be powered by a UPS from either inverter or a Pure Sine Wave inverter. Since DSL runs over a phone line, the line is still active even during a power outage. Usually cable internet connections use multiple repeaters that require power. When the power is out, those repeaters are now powered and thus, the network connection is broken. DSL still works in a power outage as long as there is power to the DSL modem.
Using a Modified Sine Wave inverter for items such as cell phone charging, laptop, fridge, incandescent light bulbs work great. It is not as smooth power being supplied, but these items are not affected adversely. The laptop or cell phone charging works fine purely for the fact that the power supplies the battery, the battery supplies the electronic device(s). The battery is a filter by itself.
Some inverters are 1,000 watts continuous, some are 2,000, 3,500, and they range on how much power they can output. Also calculate with your battery what load your vehicle can handle.
Also, while driving to and from work, using an inverter in your car to charge items such as a cell phone, laptop or such device can be useful. Once home, you have a charged laptop or cell phone batter for several hours. Don't lose the power generated from your car while driving.