Vespa EV conversion
Hi, there. I just joined the forum. I have a project in the conceptual stages and I wanted to get some feedback from the experts.
I would like to convert a vintage Vespa motorscooter to a BEV. I like the looks of the drive systems offered by electricmotorsports.com, since they include controller, throttle, contactor, fuses, wiring, and charger. I was thinking of using a 48V system with an Etek motor, using LiFePO4 batteries instead of SLA. Would anyone hazard a guess at what kind of power/acceleration that will get me?
I was considering getting the LiFePO4 batteries from electricmotorsports.com. Even though they are 40 Ah, they are expensive, and
have no included BES. How important is the BES? I'd need 15 of them to get to 48V. What kind of range will that get me? I'm seeing more attractive prices from some of the Chinese battery manufacturers, and they often include the BES. I'd like to try and fit all the batteries within the Vespa frame, so having it in several pieces gives me some flexibility in where I can locate them.
If I have to go with SLA, I don't think I'll have a problem fitting four small ones inside the frame. I suspect that my range will be substantially smaller than for the lithium cells.
A Vespa engine drives the rear wheel directly, and the rear wheel is removable from one side. The forward part of the engine attaches to the scooter frame with a pivot and is connected to the top of the frame with a spring/shock, so the whole engine acts as the swingarm. If I can find a dead Vespa engine case, I'll cut away the bits I don't need and add a mounting plate for the engine. Otherwise I'll have to build a swingarm/engine mount from scratch. The advantages to using a dead engine are that all the connection points are right where I need them and I can re-use the drum brake assembly inside the engine casing. Also a lot less welding. I might also be able to use some of the gearing inside the existing engine, although I plan to have fixed gearing.
The tire has a diameter of about 16". Will a 3:1 gear ratio work? I calculate 1200 rpms at the tire should get me to 55 mph.
I'd like to do all the lighting with LEDs, even the headlight, if I can. Maybe throw on a small amp and speakers so I can hear tunes while I ride. I assume that connecting to just a few of the series-connected batteries to pull off 12V is a bad idea, so I'll need a small transformer, correct?
Any comments on my scheme? Are there any major items I'm missing?
Thanks,
Jake
"There are a ton of EV Vespa look-alikes out there."
Well, they look like Vespas to someone not real familiar with Vespa scooters. Vespa owners certainly wouldn't be fooled. Vespas aren't made of plastic for starters. I wish Vespa or Honda made an electric version - the quality would be a lot better. Barring that, making your own electric version seems to be a fine project.
Barring that, making your own electric version seems to be a fine project.
Don't get me wrong, I also think it would be a find project - I've thought about the same idea myself, though not in as much detail (re; using the old motor for parts) as this guy has. But then I look at the stuff piled up in my garage and remember I have too many projects as it is.
- David Herron, http://davidherron.com/
Thanks for the feedback, everybody. I'm hoping to use this scooter as a daily commuter, but at the same time I'm looking forward to the project itself. I've never owned a vintage scooter, and I really like the idea of introducing one to state-of-the-art technology. I have a lot of friends who are Vespa enthusiasts and most of them are interested in seeing what I'm able to come up with. I also like the idea of doing this simply because it hasn't been done before (that I know of).
Battery space is indeed a big concern. It would be great if I could fit everything inside the body, but I realize this may limit my range. Again, if I have to go with SLA, I will, but I like the idea of using more advanced battery technology, as well as the added measure of safety and not having to replace the batteries after a year or two.
On the other hand, I could just get the 72 volt system with a Perm 132 and six 20 Ah SLAs, and save some money. This has other advantages, since Vespa bodies are steel and relatively heavy compared with newer plastic bikes, and I weigh over 200 lbs. Am I correct in assuming that increasing the voltage will have no appreciable effect on range? Also, for many batteries I'm seeing a "discharge rate" of 10C (or other) listed - can you point me to a primer on what this means?
An electric scooter from Honda would indeed be very welcome, but I already have a Honda Reflex which I love and don't intend on converting to electric anytime soon. I'll keep it for occasions when I need more speed or range. I've installed LED underbody lights on it and a stereo with dual 6" Bazooka bass tubes and it sounds pretty sweet. I won't need anything nearly that phat on the electric Vespa since it will have a lower top speed and no engine noise.
Jake
Hi Jake,
You big lug.
Luv,
Dave McCabe
The "10C" discharge rate means 10 times the rated capacity in amps. So for a 20 ahr battery this would be 200 amps.
I second reikiman. After doing my project I would much rather have just bought something electric and modified it. There is really a lot of planning, engineering, and fabrication, but if you are doing it for the project than you definitely want to go that route.
On the other hand, I could just get the 72 volt system with a Perm 132 and six 20 Ah SLAs, and save some money. This has other advantages, since Vespa bodies are steel and relatively heavy compared with newer plastic bikes, and I weigh over 200 lbs. Am I correct in assuming that increasing the voltage will have no appreciable effect on range?
It really depends on how much power and speed you want. With 72v and a perm motor I'd bet you could easily do 80 mph which will also drain your batteries in a few minutes. A lower voltage system needs fewer batteries which might cut down on battery expense some because batteries of larger capacity are slightly cheaper for the energy storage. Also you won't need as expensive a charger, and if you use some sort of BMS(such as powerCheq) it will be cheaper. So you are kind of backwards, higher voltage = more power and speed at more expense. Sure the bike could run slightly more efficiently on higher voltage, but you are also going to want to use that power to go fast and accelerate fast which will cut down the range.
Do you really need to go 55 mph? You'll get a lot more range with a slower top speed such as 40-45. Also you could cut down on motor size some. The etek is great for power, but not so efficient when you aren't going very fast. A motor of 3/4 the size would probably be perfect for this speed, but for 55 mph you'll want the etek.
I'd suggest defining the purpose and expectations of the project and of the finished product before you start the project. I did my project mostly to end up with something really quick and fun. But TBH its not that great, and any gasser can go as fast as you want for as long as you want. If I redid it I would redefine my purpose as mostly for the finished product, and for something light convenient and cheap to own. Hence, it would make a lot more sense to buy an escooter already on the market and modify it for more speed, but thats just me.
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Avatar taken from http://www.electricmotorbike.org/
My KZ750 Project: here
Oops, I've been spotted! Dude, you're everywhere!
I just arranged to buy a friend's 1970 Vespa 50S frame. Now I have to figure out how much I can fit inside...
Jake
My first question is, do you really need to do the conversion yourself? There are several makers of EV's with the styling of the Vespa, and you can be on the road pretty quick. Electric Motorsport may even be able to help you locate an Oxygen Lepton scooter, either working or as a glider. I was talking with Todd today, and he had on display an EVT 160, 60 volt, that you could buy right now.
To answer your questions...
The range/speed is determined by the kilowatt-hours you can stuff into the vehicle. If your LiFePO4 pack ended up as 49.5 volt 40 amp-hour it would be approximately the same kilowatt hours as a 48 volt 50 amp-hour lead acid battery pack, at oh.. 10x the cost, and at 1/2 the weight. Another important characteristic is the size of the two packs... would the vehicle have the physical space to hold the pack. So for example a LiFePO4 pack weighs 1/2 the equivalent SLA pack, so with the same weight you could have a 49.5 volt 80 AH LiFePO4 pack, but who knows whether it would be the same size.
Thundersky makes a BMS so I don't know why electricmotorsport isn't selling it. It may be Todd thinks it's safe w/o the BMS. The Lithium Lightning bike is built using these cells, and doesn't have a BMS, and is a very impressive bike.
The Vespa lookalikes tend to have 48 volt 50 AH of batteries, tend to do 30 miles/hr, and tend to get 20+ miles range. They tend to be hub motors however which is a different gear ratio consideration.
LED lights... one thing you need to think about, since it will be a MOPED or even MOTORCYCLE (in the eyes of the DMV), you will need to get this registered to be legal, and you will need to ensure you are using DOT certified lighting in order to be legal. Right? That said there are LED based DOT certified lights for at least the running lights. I have heard there are DOT certified LED headlights, but am not 100% sure of that.
And a sound system sounds way cool. But would it make the bike a thief target?
- David Herron, http://davidherron.com/
P.S. welcome to the board
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