When I checked on my order the model appeared to be a 700W not 750W, still more than adequate for my needs. Most auto alternators are 100+ amps. Is anyone aware of alternator output at idle speed on an auto? If my system uses 300 watts it seems like my car could run the system an build up the batteries at the same time. I plan to check on operating time with the batteries I have after the unit arrives. I wouldn't be surprised to find units in short supply with all the ice storms.WoodNotOil said:I like the look of these tripplite units from provantage. It is nice to see that they factored in the start up surge of power and can accommodate up to 200% the continuous rating in short bursts for it. That means you don't have to oversize them just to meet this need. I may consider getting one in the spring with my tax return. I assume from what was mentioned above you could must keep the unit going off of a car nearly indefinitely? In other words it could supply power for many days if a car was recharging it? Very interesting...