by "bhtooefr" (bhtooefr)
Published 02/25/2017 at 14:51
by "bhtooefr" (bhtooefr)
Published 02/25/2017 at 14:51
Tags: electric vehicles
; volkswagen
STARS: 0
I’ve been interested in electric vehicles that are efficient enough to use removable, human-portable batteries , for a while now. I’m of the opinion that this technology will enable urban EVs without having to wait on infrastructure expansion, and smaller batteries are cheaper, as well.
However, with the exception of the Estrima Birò, all of the EVs with human-portable batteries that I’m aware of are either mopeds, scooters, or motorcycles. These are great for some situations (lane splitting in areas where that’s legal, ease of parking, light weight), but there’s a few issues. There’s a distinct lack of weather protection on those vehicles, for starters.
Mopeds are slow, and all of the electric scooters with removable batteries are also slow enough to not be freeway capable. And, even when you do have removable batteries and freeway capability, the dreadful aerodynamics of a 2-wheeler mean that range is terrible on the freeway - Zero, for example, claims a range of only 37 miles at a steady 70 mph, on the FXS ZF6.5 Modular - compare to the 90 miles claimed in city riding, and 54 miles at 55 mph.
Now, in the past, I’ve posted about how my automotive white whale used to be Volkswagen’s 1-Liter-Auto concept from 2002. For those that haven’t read that piece, it was an attempt at extreme efficiency - 1.0 liters of diesel fuel per 100 kilometers.
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Nowadays, using a diesel engine for this would be considered extremely passé - electric vehicle technology has come a hell of a long way since 2002, and there’s been a small matter of a minor diesel emissions scandal , which VW’s at the center of.
So, how efficient could it be if it were electric? Well, there’s a couple ways to come at it.
The first way is to look at Volkswagen’s claimed efficiency for the 1-Liter-Auto - 1.0 l diesel/100 km, presumably on the NEDC - and figure out how that translates to electric efficiency. A liter of diesel has about 9.95 kWh of energy (based on Alternative Fuels Data Center data )... but that doesn’t tell the whole story, because electric powertrains are significantly more efficient than internal combustion. I don’t have a great direct comparison - there’s a lack of vehicles available in both diesel mild hybrid form and battery-electric form - but I’d expect an electric version of the 1-Liter-Auto to use somewhere between 26 (based on the 2015 Golf TDI versus the e-Golf) and 40% (based on both the Volt and Prius Prime in charge sustaining versus charge depleting modes) of the energy of the actual 1-Liter-Auto, and I’d expect it to be closer to that 26% end. However, I’ll use 40% for this, because I don’t trust NEDC numbers, and I’d say that’s a fair skew factor. That means that 3.98 kWh of energy is required to go 100 km. Or, to go 100 miles, 6.41 kWh is required.
The second way is to look at the power figures and top speed. Volkswagen claimed 6.3 kW of engine power, and a top speed of 120 km/h. Let’s make a few assumptions here - first, that 6.3 kW is actually needed to hold that top speed, and second, that holding 120 km/h is actually the real worst case scenario. You’re looking at 5.25 kWh per 100 km, or 8.45 kWh per 100 miles.
As far as the battery situation... Zero’s 3.3 kWh batteries (two of which are used in that bike) are roughly 42 pounds each - heavier than many recommended lifting weight limits, which are set at 35 pounds. Then, the actually usable capacity is about 2.9 kWh - so to get 35 pounds, you’re looking at about 2.4 kWh usable. That means that, with two batteries, you’re looking at a range of somewhere between 57 and 75 miles depending on how pessimistic of an estimate you use, including freeway capability, in something with car comfort and weather protection.
Contrast with the highway range you’d get on a Zero with 4.8 kWh usable capacity - only 35-41 miles, and even the 35 mile range is at lower speed than the 57 mile estimate for the electrified 1-Liter-Auto.
Yeah, I think the 1-Liter-Auto is my white whale again, just electrified this time. Scooters have their place - they’ll be a hell of a lot easier to park than this, they’re lighter, and you sit up higher - but this is capable of even short freeway jaunts. And, you still get to carry the batteries inside to charge them, rather than having to get the car near a plug.
"Leon711" (leon711)
02/25/2017 at 14:57, STARS: 0
Why not consider the more conventional XL1 instead? It has a lower Cd than the 1L and is generally a more stable and highway capable vehicle.
"bhtooefr" (bhtooefr)
02/25/2017 at 15:10, STARS: 0
Except it doesn’t have a lower Cd - 0.159 for the 1LA, 0.189 for the XL1 - and, worse, it has a lot more frontal area, too - 1.0 m^2 for the 1LA, 1.5 m^2 for the XL1. Upshot is, the XL1 has 78% more aerodynamic drag.
"pip bip - choose Corrour" (hhgttg69)
02/26/2017 at 03:56, STARS: 0
they should put a 1-cyl motor into it.
"Rusty Vandura - www.tinyurl.com/keepoppo" (rustyvandura)
03/12/2017 at 22:44, STARS: 0
I saw your post about the Prius transmission. I confess there were too many words for me to read it all, or all of this one.
My brother-in-law owns a 2nd-Gen Prius and a (whatever) 5 Prius, the one without the Captain Kirk command com island. Without sounding like a troll, I want to share my opinion that I really do not like hybrid cars, even though my BIL’s first Prius is approaching 150k miles, though the engine clatters and the drive batteries are probably only 30% of what they once were. For my money, and I will
never
be able to afford one, I have my eye -- and my money, since I own a bit of stock — on Elon Musk.