Okay, so I’ve described how I charge my electric motorcycle– I plug it into a standard wall socket. Next question (and the one I get a lot): haw far can you go, on that charge? Short answer: It depends.
The manufacturer’s EPA range claims are for the small and large battery packs. On the standard, ZF6 battery, Zero claims 76 miles city, 43 highway for 2012. The large, ZF9 pack then gets 114 miles city, 63 miles highway. Now, a good engineer (as well as marketers and dealers) would then ask the next logical question: ‘Where do these claims come from? Under what conditions?’ Basically, ‘why?’
The city figure is easy enough: the EPA has an UDDS cycle (urban dynamometer driving schedule), which lays out the test parameters. A certain number of stops, a certain number of accelerations, to a certain speed, etc. So far, so good. The highway number, however, does not list a driving cycle. Zero considers this “cycle” to consist of half steady-state operation (i. e., freeway cruising), plus half surface streets, to get to and from the highway ramps. In other words, a mixed cycle. They got dinged for it, and for 2013 list separate city, highway-only, and mixed range numbers.
Next, next, next question: what’s been my experience, riding a production vehicle on real-world roads? Zero may have equivocated, but they didn’t lie. Again, the test cycles can be replicated by independent testers, and Zero didn’t particularly feel like getting caught on this. In urban riding, a charge basically lasts forever. You’ll run out of butt strength and bladder size long before you run out of battery. I have never had an issue with range in-town; based on my commute (6 miles each way) I could and do skip a night of charging every now and then. If I make no side trips, I could commute most of a week without recharging. Even that’s not an issue, since my side trips are mostly stores and restaurants along the way to work. Not much more than a mile extra, three at most.
Okay, what about highway riding? Again, Zero didn’t come up with their number from thin air. Highway riding returns much lower range, unlike cages in general, and gasser cages in particular. The difference is drag. Motorcycles may look cool in a general and social sense, but from an engineering stance, they’re aerodynamically filthy. An exposed rider, with their arms and torso sticking up, will never be clean. Aerodynamic “sleekness” is measured by a ‘coefficient of drag’ value (Cd). Where a well-designed car might have a Cd=0.30 or even less, a motorcycle with rider is about 0.7. That’s as aerodynamic as a pickup truck, or as un-aerodynamic, I should say.
So overall, I have found that highway range is… variable. I’ve tucked extra low; I’ve drafted behind trucks. More on that later…