How many KW needed for EV?

W

Wurly

100 W
Joined
Dec 29, 2008
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156
Location
Somerset, UK
I have 58VW Bug that has been in the family for over 10years. I bought it and restored, lowered, painted it added porsche wheels and low profile radial tyres and gave it to my daughter. She had good time driving a pretty kool car around for a few years.
Times have now changed. She is married and has a family of her own, so the bug has been neglected for a while. I'm loathed to sell it, we put a lot of work into it. When i say we, i mean my daughter me and also my dad who is now a great grandad. You can all see, the old VW is part of the family.
So what now for the VW?.... EV/VW? .....just like the 57 VW samba on another thread here.
I've seen many opportunies to buy s/h cells at reasonable money and have been tempted, but how many do i need. What voltage and how many ah's is required to make it go? forget range for now. I'm wondering KW's (i know my ebike requires 850W to make 20-24mph.)
Is there a formula or simulator i can use that includes weight, rolling resistance, etc
Thanks in advance for any input
 
I mean, why not have a look at the engine the car had originally ? Apparently (google) it had 36 hp originally, so about 25kW.
I would look for a motor that matches what the original did, so 25kW at 3600 rpm. Agni makes a 10kW motor at 4000rpm, so 2 of those should do it.

A 12kWh battery will keep it going for half an hour at full throttle.


|/
 
A much better CAR forum is diyelectriccar.com. There are many VW builds. There may even be parts in the Classifieds. There are several Brits on there, also.

Not meaning to chase you away from here, only helping with the info you want.

Good luck and stay in touch, here. s there and you can find ways to make the conversion much more affordable.
 
Going with an "equivalent" power motor compared to the gas engine will not give equivalent performance. The reason is that the torque will be much higher and across a wider range than the old gas engine.

That said, I have an old airplane starter/generator motor that used to be a popular motor for small conversions like yours. It came out of an S-10 EV a local guy built, running 48V at about 400A peak (he said ~100A at 50mph). It's also capable of regen (search for SEPEX controllers). It would be just about perfect for your conversion, PM me if you're interested in it as it's just sitting in my garage right now.
 
...You can all see, the old VW is part of the family.
So what now for the VW?.... EV/VW? .....just like the 57 VW samba on another thread here.
Click to expand...
You really need to read more of those VW conversions before you decide what to do with the "family 'VW".
Even the "Samba" , ..which in many ways is an easier conversion due to the extra space for batterys etc,.. is taking a lot of time , effort and money, as do most of the conversions if you read between the lines.
Apart from the actual conversion, you still have to fix, repair, service, the rest of the car and probably have to get an Engineer's report ( and MOT etc) before you can legally drive her.
Perhaps, the biggest issue may be that after all is done, you will have invested many thousands of pounds into the conversion, only to have actually de-valued the original VW !..both financially and emotionally ( no more of that familiar "chug-chug" distinctive VW sound )
 
I have many resevations. Most listed above. I was last thinking about parts availability. If you cut something short, will you get another one, or will you get lynched trying.

Perhaps another car? If that was acceptable, consider an mx5. Companies already take the £1000 mk1 of 20 years ago, and tart them up to sell as something new. Best selling sports car ever, with lots of forums devoted to them. Popular enough for someone to want a kit. It's front engined rwd and light. A few aftermarket front subframe's exist. Most tubular and give clearance for a V8. You could raise the car 2", fill the archs with big wheels, fit some deep side skirts to make it appear lower to the ground, then stick batteries in the void. Adding a roll hoop that actually supports the floor off the tunnel.

With the rwd arrangement you just have to join propshafts to stick in lots of different motor/gearbox combinations proven to work in other cars. The mx5 can already present a number of gearboxes due to aftermarket kits too, so with unlimited budget hardly any fabrication work would be needed. It has all been done somewhere before. Just gotta pay them to do it again.


I have no idea what such a project should cost in either car. How many 4s packs is that?
 
A guy in town here built a geo metro EV ( with aerodynamic optimizations ) using a double stator motenergy motor designed for a motorcycle. Top speed is only about 62mph or so, but he drives it in the city primarily.

He's got it hooked up to the original gearbox, which is the only way that he manages not to blow it! but it does get very hot climbing hills at over 40mph.

For an $8,000 conversion though ( includes 16kw-hrs of lifepo4 battery ), i was impressed with how much power and range it has ( ~70 mile range at 50mph ).

An old bug could possibly be powered in the same way... but better, since it's rear motor / rear wheel drive :)
 
I was just thinking some more about the miata. The fuel tank sits above the rear subframe where you can really pile some weight. Plus it has a transverse silencer box that takes about as much space under the boot, as the boot does above it. It has been done though. Does 0-60 in 1.3
 
0-60mph in 1.3sec?

Totally possible of course, but it couldn't be done on a Miata factory rearend, and you would likely need at least a 13" motor, a pair of 11" motors or a 0-60mph first gear if they are accomplishing it with smaller motors somehow.
 
liveforphysics said:
0-60mph in 1.3sec?

Totally possible of course, but it couldn't be done on a Miata factory rearend, and you would likely need at least a 13" motor, a pair of 11" motors or a 0-60mph first gear if they are accomplishing it with smaller motors somehow.
Click to expand...

Metric just turned a 1.349 in his Miata using dual Warp9 motors. http://www.diyelectriccar.com/forums/showpost.php?p=382704&postcount=150
 
Yep, looks like what I would expect if you wanted to do it with a pair of 9" motors. Lenco trannys are amazingly robust.

4558d.jpg

Seems like a pity to add a bunch of drivetrain mass and drag and inertia that is non-contributing to converting electricity to thrust, but only making a lossy force conversion, over perhaps just running a pair of 11" motors and no tranny, but that's just my humble opinion, he is the one who has a drag car faster than any I've owned after all. :)

I'm also glad that I will have someone to race against when my Cayman project gets finished enough to race. :)
 
liveforphysics said:
0-60mph in 1.3sec?

Totally possible of course, but it couldn't be done on a Miata factory rearend, and you would likely need at least a 13" motor, a pair of 11" motors or a 0-60mph first gear if they are accomplishing it with smaller motors somehow.
Click to expand...

He is doing 9 seconds. Miata's can do that on the standard diff, but you only get a few runs. Some nutter over there does it.
Chances are you would want a bigger diff though, not a life spent changing them. Which is fine, there are kits to fit one. It sits within a substantial metal subframe with space around it, so putting in another is not a bad job. It's not a car that uses tie rods to floor strengthening plates. It has a big rear subframe that everything bolts too.
Just one suppliers options https://www.flyinmiata.com/index.php?deptid=5675&parentid=0&stocknumber=26-08002%20%208.8S3

Realistically the stock diff holds 300bhp. Better expressed as torque, but always linked to bhp in forum posts. I guestimate 250lbs for the 1.6 and 300lbs for the 1.8 diffs (6 or 7" respectively)

The real reasons for the miata is sitting here and ordering nearly everything done for you. Leading to a car others can easily work on, and a car others desire. Lots of space, lots of forum help. Everything has probably been done before. You could probably manage the build rather than have to make it yourself. So you couldn't get stuck.
 
Thanks for the replies.
Yes the old car is probably worth about £3500 maybe more, not a huge value and certainly not rare.... and it's not for sale anyway so.
Yes i had thought about another vehicle ...something like a French Microcar. It's small and light and i could get one pretty cheap with a blown engine however i would prefer the EV bug.
I think the conversion could be done without much modification of the main structure of the beetle, so it could be reversed if required at a later date.
As regards the legality....well, it's never stopped me doing car mods before, so it ain't going to start conforming now, besides the bug has historic status so with careful mods that shouldn't affect it.....although i think fuel type would have to be changed with dvla(something else to check out).
As it stands the car is zero tax and no mot. Insurance could be a hassle but there are specialist brokers.
For the reasons stated, i think i already have a good candidate for an EV conversion, but it will require some real planning and collecting.

Harold, thanks for the link. Yes i have seen that forum. I am always reading and learning many things from clever folks on Ess especially with regards to batteries and battery management and there is half a dozen car related threads running in this section so i figured it was ok to post. I take your point though.

dmwahl, thanks. Nice to seeing some real figures there. I used to manhandle one of those started motors. It was used to fire up a nitro funny car we to run here in the UK. I was the guy on the button and my friend was the guy who pulled the lead of the magneto. Damn thing was really heavy, yet when that motor fired and started spitting flames i somehow found the strength(adreneline) to disengage and whisk it away pronto.
Pm'd you

Hillhater, you know, i don't think i mind loosing the 'chug chug' sound lol
Fuel is really expensive here and for a 1200cc motor @6.5:1 compression designed to run on any crap fuel available it only whacks out 36hp, it really doesn't do many mile per gallon. The torque figures are probably impressive but HP isn't.
Getting to evaluate the exact motor required (whether ac or dc) is a further step, right now KW cruising and max KW for incline is where i'm at.

Two motors and a lenco look impressive but i think they would be sticking out the front of the car :D
 
Yes i know of the Black Current VW but yet to see it or meet them. My nearest track is Long Marston , Worcester and the meets i attend do not usually include Vw's. I will try to get to the alternative energy drags at Santa pod(200miles away) this year.
I'll be on my own as my mates have zero interest in EV's
 
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