I've had my Prius option #4 for about 3 weeks now. I have a couple of questions. 1.) When its very hot out, 90+ does mpg go down due to battery heat/capacity? Obviously I'm running A/c full blast so that might take a slight hit but seems like I'm down in the 43-44 mpg right now where a week or two ago I was in the upper 40's. 2.) Has anyone used a power inverter in a Prius to power a laptop? I've never used one but was worried if I tried it for a road trip this summer that the drain on battery may be higher in the Prius than on other cars. The laptop would be running while we are driving not when parked. Basically used for internet surfing for my wife via cingular card. Just wanted to see if anyone has used one without negative effects on battery life or mpg.
Welcome to PriusChat and Prius-dom! Can I assume you're doing a fair amount of city or other low speed driving? The AC runs off the hybrid battery. If you're cruising along on the highway or elsewhere where the internal combustion engine (ICE) runs (and recharges the battery) anyway, AC's effect on MPG is minimal. The effect is greater in stop and go driving. After the AC drains the battery to a certain level (generally about two purple bars on the MFD battery display) the ICE will kick in to maintain the charge. That may happen at times you don't need the ICE for propulsion, sometimes even when you're sitting still. The inverter should cause no problem. I use one that plugs into the accessory power jack below the dash. A laptop's power requirements are pretty trivial compared to the high-current devices (like the AC) the car is powering.
*Do* use the A/C in hot weather. The battery system gets its cooling air from the cabin through the vent at the right of the rear seats. If you are too hot, then the battery is also too hot to work at full efficiency.
