Vespa 150 VBA1T Conversion

[dpstah]

Hello! I’m starting this thread to share details of my conversion build of a 1960 Vespa 150 VBA1T. This project first started as a restoration, but I decided I didn’t want the maintenance of a gas engine. The goal of the project is to preserve the beauty of the original design, but marry with the modern convenience (and hopefully longer term sustainability) of an electric engine.

I started with the conversion kit from AliExpress, which included:
QS 72v 2000w hubmotor 10”
Fardriver controller
12v DC converter
Electronic throttle and battery indicator

I also bought a new wiring loom from SIP scootershop to clean up the original wiring and upgrade to 12v.

After the kit arrived, I realized after it arrived that my scoot per doesn’t have an opening on the handlebars anywhere for the electronic throttle wiring, and I didn’t want to drill holes in the frame, so I needed another solution. I opted for the Sur-Ron analog-to-digital throttle adapter, and a generic keyless starter system from Amazon. Will have to find a solution for a battery indicator though. Thinking I can put a hardwired indicator in the glove box, or hopefully I can find a battery with a Bluetooth BMS and I can just use my phone while riding.

I was stuck on the swingarm for a long time - welding isn’t part of my skill set and I couldn’t find any local fabricators that were willing to take the project on (at least not in a way that was cost-effective). I finally lucked out and found an off-the-shelf swingarm on AliExpress that looks like it will be almost an exact fit for the frame and hub motor. Fingers crossed! The only thing that doesn’t look like it will work out of the box is the placement of the shock mount, so I will have to figure out a plan for that. Hoping I can find some sort of bracket or extension that I can attach that will work? Any thoughts or advice on this appreciated!

Still working on sourcing a battery! Suggestions appreciated on this also.

A few pictures attached.

 

[John_Doe]

Nice, i love Vespa projects. What range & speed are you aiming to get out of it?

Do you have a link to the conversion kit? If it wasn’t that hard to get it road legal in my country I would attempt one myself.

Good luck with your build, keep us posted!

 

[dpstah]

Thank you! Here is the link for the kit - although I will note this isn’t exactly what I ended up buying, I worked with them to customize, so the engine and controller are different. It was a reasonable starting point though!
https://www.aliexpress.us/item/2255800962985912.html?spm=a2g0o.order_list.order_list_main.9.21ef1802lJOiaR&gatewayAdapt=glo2usa4itemAdapt&_randl_shipto=US

Hoping for 40-45mph top speed and 35m of range, which seems reasonable according to this calculator:
https://escooternerds.com/electric-scooter-calculators/electric-scooter-range-calculator/
I may consider a second battery to add more range, but for now, I just want to get it running.

I’m a bit on the fence about where I want to end up on the top speed - for my state, 40mph is the cut-off for registering as a limited use motorcycle vs. regular motorcycle. Limited use means you are allowed to park on the sidewalk!

 

[SlowCo]

The Vespa looks great. Good luck and enjoy the build process. And update often with lots of photos in this thread

 

[dpstah]

The swingarm arrived today!
Posting pictures below - the design wasn’t quite exactly as pictured, and what they sent me maybe isn’t quite as compatible with the classic Vespa style as the pictures of what I thought I was ordering. Hopefully the measurements will be as advertised!
https://www.aliexpress.us/item/3256803785958341.html

Also, working on battery sourcing. It looks like size will be the main limitation. Primitive cardboard prototype reveals I can reasonably accommodate two batteries 72v 30Ah, one triangle under the seat in the gas tank space and one rectangle under the fender where the engine used to be.

Has anyone tried a configuration with two different batteries to increase range? I’m wondering if it’s an issue if they have slightly different operating parameters, if they can be configured to “match” via the BMS or if I would have to switch between them.

These are the two parameters that are different.

Peak Discharge Current:80A
Discharge Cut-off Voltage:50+/-1 V

Peak current: 100A
Discharge cut off voltage: 56V

 

[SlowCo]

Beefy swingarm. Hope you can make it fit. Would look better on this Vespa if you painted the milled/natural aluminium black, I think.

Are the battery packs made out of the same cells? Because the discharge cutoff voltage differs too much. But 50 instead of 56V could also be a typo? I'm not sure where/from who you will buy the battery packs but if it is a manufacturer they can often make packs to your requirements in size. It looks like you could fit a much larger battery pack in that space under the seat.

 

[bernietime]

Love the project! I've converted a couple of Vintage Vespas to electric as well. One, I built for a friend using the kit from retrospective Scooters in the UK. The kit alone is 5.5k (yikes). But you definitely get what you pay for. And it was his money, not mine!
That gave me the courage to try to make my own kit. I designed a swing arm in CAD and sent it off to sendcutsend. It came back perfect! I welded it together and I have perfect bolt in swing arms from vintage small frame and large frame vespas.

Here are some pictures. I am running my set ups with a 3kw hub motor, 100amp controller and a 52V battery. There's room for more speed and acceleration but it works well for what it currently is!

 

[PtheDude]

Super jelly of you both. still looking for decent bones to make this happen, Bernie, you ready to sell a swingarm? I believe you told me no once already... That's the hardest part, especially with a Lam. I LOVE the no harm approach, the Vespa hardcores won't brand you heretic & chase you around town with their little beeping horns. for the OP, it's easy to weld. not hard to start at all. Welding...well. That, is different.

 

[bernietime]

Super jelly of you both. still looking for decent bones to make this happen, Bernie, you ready to sell a swingarm? I believe you told me no once already... That's the hardest part, especially with a Lam. I LOVE the no harm approach, the Vespa hardcores won't brand you heretic & chase you around town with their little beeping horns. for the OP, it's easy to weld. not hard to start at all. Welding...well. That, is different.

My swingarms are ready to go! Send me a message and we can talk specifics.

 

[dpstah]

Well, the first swingarm was a bit too long, so I ordered another one to see if that works out any better. If that doesnt work, then @bernietime I’ll be hitting you up!

in the meantime, I’ve been working on getting the electronics sorted. Power distribution is working! Now, to start getting the components where they should be on the scooter….

I have encountered some trouble with the Fardriver controller and connecting to the iOS app via Bluetooth. I can see the connection but I’m not connecting properly or receiving any data. Anyone have any helpful hints?

 

[dpstah]

Super jelly of you both. still looking for decent bones to make this happen, Bernie, you ready to sell a swingarm? I believe you told me no once already... That's the hardest part, especially with a Lam. I LOVE the no harm approach, the Vespa hardcores won't brand you heretic & chase you around town with their little beeping horns. for the OP, it's easy to weld. not hard to start at all. Welding...well. That, is different.

I’ll have to see if I can dig up some “before” pics for you! i lucked out with the bones being mostly original, just a lot of coats of spray paint over the years.

 

[dpstah]

Nice, i love Vespa projects. What range & speed are you aiming to get out of it?

Do you have a link to the conversion kit? If it wasn’t that hard to get it road legal in my country I would attempt one myself.

Good luck with your build, keep us posted!

I talked with my local motorcycle inspection station last week, and it seems that at least in my state in the USA, ”road legal“ for an EV conversion might not be too difficult, especially if the original capacity is under 300cc. For inspection, they mostly look for the functional safety features (brakes, mirrors, turn signals after 1974, etc.) Curious to hear what your restrictions are?

 

[dpstah]

Some progress! The good news is that I managed (with great difficulty) to fish a new harness through the frame, install a new handlebar switch, and all of the positive wires I tested appear to be receiving the correct voltage.

However, I’m stuck on how the neutral wires should be connected so my lights aren’t working correctly just yet.

For the wires I don’t know what to do with, I’m trying to use the two resources that I have to figure out what their function is - if I know that I can figure out how the 12v electronics should be wired.

See below for:
- Wiring diagram from original owners manual
- Wiring diagram that came with the new wiring harness

1) The original wiring diagram shows the 12v battery connecting the neutral wire to a screw on the frame. With the new schematic, there is no separate 12v circuit, just a step-down converter. Seems like not a great idea to connect the main 72v neutral wire to the frame.
Is there another neutral wire carrying 12v would be a better candidate? (Assuming of course there are neutral wires upstream of the main neutral connection to the battery- see related questions below)

2) Gray wire - from front parking light to ignition coil in the original diagram. Power to the parking light is being provided by the wire from the handlebar switch, so guessing this should be a neutral wire? The headlamp unit is the only light that doesn’t appear to use the frame as the neutral wire.

3) White wires, connecting from low tension terminal thru to stator plate. What is the purpose of this? If I had to guess, I would say maybe it’s a neutral wire, but not sure for what? Is this needed in the new configuration?

4) Yellow-black - connects from handlebar switch thru to stator plate. Maybe a neutral wire?

Thanks in advance for any clarifications!

 

[amberwolf]

1) The original wiring diagram shows the 12v battery connecting the neutral wire to a screw on the frame. With the new schematic, there is no separate 12v circuit, just a step-down converter. Seems like not a great idea to connect the main 72v neutral wire to the frame.

If your DC-DC is isolated, so that there is no continuity from either output wire back to either input wire, then you could ground the DC-DC negative wire where the original battery negative went, so your frame is lighting ground, and all your lighting / 12v equipment will operate as it used to without any modification. The 72v (traction) pack will have no frame connection from this.

If your DC-DC is not isolated, then you'd be grounding both to the frame, and so any wiring or component failure in the 72v system that shorts battery positive to the frame would short the battery out.


If you don't want to use the frame as 12v ground, then you also have to modify all the 12v and lighting equipment on the Vesta to electrically isolate it from the frame, or else you are still using the frame as ground even if you run separate ground wires to each light and piece of equipment.

Myself, I use separate wires to everything on my bikes/trikes, after numerous problems with frame grounds failing for various reasons on my old original version of CrazyBike2, causing lights to be intermittent or not work, etc.

Is there another neutral wire carrying 12v would be a better candidate? (Assuming of course there are neutral wires upstream of the main neutral connection to the battery- see related questions below)

You would need one for each light and piece of 12v equipment. How many lights do you have? How many unused wires do you have that run to the same places on the Vespa that the lights and any other 12v devices do?

 

[dpstah]

If your DC-DC is isolated, so that there is no continuity from either output wire back to either input wire, then you could ground the DC-DC negative wire where the original battery negative went, so your frame is lighting ground, and all your lighting / 12v equipment will operate as it used to without any modification. The 72v (traction) pack will have no frame connection from this.

If your DC-DC is not isolated, then you'd be grounding both to the frame, and so any wiring or component failure in the 72v system that shorts battery positive to the frame would short the battery out.


If you don't want to use the frame as 12v ground, then you also have to modify all the 12v and lighting equipment on the Vesta to electrically isolate it from the frame, or else you are still using the frame as ground even if you run separate ground wires to each light and piece of equipment.

Myself, I use separate wires to everything on my bikes/trikes, after numerous problems with frame grounds failing for various reasons on my old original version of CrazyBike2, causing lights to be intermittent or not work, etc.




You would need one for each light and piece of 12v equipment. How many lights do you have? How many unused wires do you have that run to the same places on the Vespa that the lights and any other 12v devices do?

They are not isolated. I didn’t think of this before, but I suppose it would be easy enough to add a 12v battery for the lights so everything in theory should just work. I definitely don’t have any more room for extra wiring through the headset, it was a tight enough squeeze for the wires that are supposed to be there! Thanks very much for the feedback!

 

[amberwolf]

If you use a 12v battery, use a LiFePo4 4s, as a Li-Ion doesn't have the right voltage range in 3s or 4s. They make LFP "starter" batteries for motorcycles that you can just use straight up.

You can get isolated DC-DC's; if you do I recommend making sure it's output is 13.6-14.4v rather than straight 12v, to emulate the typical battery/alternator voltage (otherwise your lights will be dimmer than they should be).

Also make sure it's input can handle the 84v+ max a 72v pack typically reaches at full charge--I'd just go right for a 100V input, so that if you ever use regen and get voltage spikes it doesn't blow up the DC-DC.

It has to be able to output the total current that all your lights will ever use all at once, plus some significant extra margin for any horn you have, and for turning on any incandescent lights as they take way more power at turn on than to run once on. So if you measure a total of 10A when all your stuff is on, get somethign that does at least 20-30A so it can handle the spike loads of horns and turn on of headlights and stuff. If you're using LEDs instead of incandescents you can get probably away with a much smaller DC-DC, just big enough to handle the horn's turn-on load.


I recommend posting a link to whatever you're considering buying so we can look at it and make sure it actually does what you need it to.

isolated 72v to 13.6v dc-dc - Google Search

These are some from places that sell EV parts, but there's plenty of others; I have not used any of these companies just found them on the google search's first page.

High voltage input DC/DC Converter Catalog, to convert voltage up or down, retail, wholesale, off-the-shelf and custom, DC/DC 5 watts to 1500 watts, voltage from 72V to 380V, DC/DC power supplies

72V input DC/DC converters, 110VDC, 220VDC input DC/DC power supplies open frame, closed frame, modules, bricks, and custom converters

www.powerstream.com

Converter | EVlithium

{sdcms:class_dec}

www.evlithium.com

DC-DC Converters Wimech HW STC OBC | Electric Car Parts Co

There is also the Meanwell LED PSUs, like the HLG and ELG series that are potted/sealed, that may work on your system voltage (they're meant for AC input, but they also make DC input versions and some of the AC ones work fine on the DC). It's been a while so I don't recall the details but I tested one of the "12v" (goes up to 14v, IIRC) HLGs powered from a 28s battery and it worked to run my lights on the SB Cruiser. It didn't work on the 14s pack I actually run the trike from, though--it might work on a 20s like yours.

These are from "raw electronics" places that take more work to connect up:

https://www.arrow.com/en/categories/power-supplies/isolated-dc-dc-converters

 

[vdubjim]

Did your new swing arm come in?

 

[martinev]

Love the project! I've converted a couple of Vintage Vespas to electric as well. One, I built for a friend using the kit from retrospective Scooters in the UK. The kit alone is 5.5k (yikes). But you definitely get what you pay for. And it was his money, not mine!
That gave me the courage to try to make my own kit. I designed a swing arm in CAD and sent it off to sendcutsend. It came back perfect! I welded it together and I have perfect bolt in swing arms from vintage small frame and large frame vespas.

Here are some pictures. I am running my set ups with a 3kw hub motor, 100amp controller and a 52V battery. There's room for more speed and acceleration but it works well for what it currently is!

Hi sorry to bump this thread. FYI. maybe we can help with the swing arm issues in future world wide postage .. Thanks ( Martoni)

 

[shawnm]

Some progress! The good news is that I managed (with great difficulty) to fish a new harness through the frame, install a new handlebar switch, and all of the positive wires I tested appear to be receiving the correct voltage.

However, I’m stuck on how the neutral wires should be connected so my lights aren’t working correctly just yet.

For the wires I don’t know what to do with, I’m trying to use the two resources that I have to figure out what their function is - if I know that I can figure out how the 12v electronics should be wired.

See below for:
- Wiring diagram from original owners manual
- Wiring diagram that came with the new wiring harness

1) The original wiring diagram shows the 12v battery connecting the neutral wire to a screw on the frame. With the new schematic, there is no separate 12v circuit, just a step-down converter. Seems like not a great idea to connect the main 72v neutral wire to the frame.
Is there another neutral wire carrying 12v would be a better candidate? (Assuming of course there are neutral wires upstream of the main neutral connection to the battery- see related questions below)

2) Gray wire - from front parking light to ignition coil in the original diagram. Power to the parking light is being provided by the wire from the handlebar switch, so guessing this should be a neutral wire? The headlamp unit is the only light that doesn’t appear to use the frame as the neutral wire.

3) White wires, connecting from low tension terminal thru to stator plate. What is the purpose of this? If I had to guess, I would say maybe it’s a neutral wire, but not sure for what? Is this needed in the new configuration?

4) Yellow-black - connects from handlebar switch thru to stator plate. Maybe a neutral wire?

Thanks in advance for any clarifications!

They are not isolated. I didn’t think of this before, but I suppose it would be easy enough to add a 12v battery for the lights so everything in theory should just work. I definitely don’t have any more room for extra wiring through the headset, it was a tight enough squeeze for the wires that are supposed to be there! Thanks very much for the feedback!

I don't think you need a 12v battery. I would connect the DC/DC converter output wire (red) to take the place of the main power wire that would have come off of the Vespa stator. The load is not really very large. I did this when I converted my Heinkel Kabine microcar. That draws more power than my Vespa VBB so I think you will be fine and save space.