Interesting topic. We have a small electric commuter vehicle with a roughly 18 KW battery. At 92 percent charge the car sends me an email and lets me know I am at 92 percent. It noticeably slows down after that, not horribly but noticeably. Mercedes recommends not bothering to plug it in if it is not below 80 percent at the end of the day. But for those with longer commutes at 80 percent of their range the last 20 percent is important, especially in cold (heater) or cold (AC) conditions which weigh on the range. I don't know much about the battery in our car but there must be something special about that last 10 or 20 percent.
High speed (read highway speed) sucks up juice fast. My commute includes about 20 KM at 110 KMH every day. For giggles and grins or when passing someone I occasionally run it up to 130 KMH and you can almost see the range meter move. That 20 KM portion of my commute at those speeds takes about 15 percent of the range at that speed. Air resistance, etc. Can you imagine the current draw a motorhome going through the air would be? Better have a big battery. :) The around town portion uses much less though. Every time the brakes are applied or even when the go pedal is released power is flowing back to the battery. I usually have more KM remaining on the range meter at the bottom of a long hill than at the top. :) I imagine that would also work on a motorhome. Ours is an inexpensive commuter car with limited 150 KM range (city) or 115 or so on the highway. The big boys like TESLA employ the high current rapid chargers. That is what a motorhome would need. Charge time for a commuter car is irrelevant as you treat it like a cell phone. Plug it in when you get home. Its charged in the morning. Wether it takes an hour or 11 hours is irrelevant as I am sleeping while it charges. :) Having said that, in a year or two when we replace our last oil burner with another electric we will be hoping for a level 3 fast charger. :)
Oh, and reference acceleration in these electric vehicles, silly fast is an under statement. In the first 60 KMH I can pretty much dust off any camaro, mustang or whatever. Not as crazy fast after that but still very responsive. Computer limits it to 135 KMH. Not a speed I travel at much. Now the TESLA. Angela and I took a tesla for a drive. 0 to 60 MPH (0 to 100 KMH) in 2.7 seconds. Pretty humbling for cars like Lamborghini , Ferari, Porsche etc when a 130 thousand 5 passenger sedan with cup holders leaves them in the rear view mirror. :) Too fun.
