If you have a pure electric vehicle you're a captive audience and have no choice. That's who the pay charging stations are really aimed at.So I just got this iPhone app that shows a bunch of charging stations & I notice they charge $2.00 an hour. Hmmm let's do some math. I may be incorrect in my calculations but it takes about 6 hours to charge a Karma at one of those, so basically $12.00 to obtain a full charge. On a full charge I'm getting 35 real miles in my car under normal driving conditions. So basically if I charged my car at a charging station I would be paying 34 cents per mile. Currently right now gas in my area (TX) is $3.16 a gallon. If I decided not to use the charging station & just run my ICE it would cost me 14 cents per gallon (this calculation is based on 22mpg running on ICE mode). That's less than half the cost to goto a charging station. If u were to break it down, if u went to a charging station, it's equivalent to getting 9mpg! My V-12 Lambo gets better mileage than that. So why would anyone want to goto a charging station???? Other than the fact they want to be Eco-friendly of course. Again my calculations may be off which would throw this whole thing out the window
With the Karma (or the Volt) the range extender gives you choices, and your math is correct. On a strictly dollar basis, paying $2 an hour to charge is very expensive, and not at all worth it. For me, it's also about 500% more than I pay charging at home. There were a few threads about this many months ago, but the general consensus was Free was a no brainer, $1/hour was about as high as most people would go, and anything more more was ridiculous and not worth it. For me, I'll use free chargers where I can find them (they are scarce, but growing in Atlanta) but I've never paid to charge.