<p>To answer the question of why you would use two: <br><br>I use two for redundancy and efficiency. Large loads need big inverters to power them. Most inverters will scale down their power use to the load that is being placed on them, but they all have a minimum amount of power that they use just when they are powered on. Generally, the larger the inverter, the larger this parasitic power draw is. Most items that need large inverters are not used constantly. You will only use a microwave a few minutes per day probably. There is no need to waste all the extra power required to keep the big inverter on constantly for that few minutes of big power draw each day. I use a much smaller inverter for the majority of things that get powered in the van. The television, dvd player, and antenna amplifier all draw less than 200 watts combined. The refrigerator runs at about 150 watts intermittently. My 1000 watt inverter will easily handle all of that and have enough surge capacity to handle the refrigerator compressor when it turns on. Because its smaller, it is more efficient and doesn't waste as much power just by being on. <br><br>I could get by with a smaller inverter, but redundancy is why the smaller one is a 1000 watt model. My system is wired up so that one inverter can step in and take the place of the other in case of problems just by moving the plug from one to the other. Both can power anything. My microwave is small. It is a 700 watt model. It's actual draw at full power is just over 1000 watts. I can adjust the power level to 50% and that drops the power draw to around 750 watts. Takes a little longer to cook, but it will work with the smaller 1000 watt inverter if the big one ever dies on me.</p>