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I want to build an EV! Where do I start?

829K views 415 replies 165 participants last post by  whelmed 
#1 ·
For all new members and first timers, here is the basic guide to getting started.

If you haven't already you will need to Register to post in our forums

Start by posting a new topic in the EV Conversions Forum.
A good topic might be "Planning <make> <model> conversion"

What you will want to post is:
  • Your skill level with auto mechanics and fabrication
  • The range you are hoping to get (how many miles/charge)
  • What level of performance you are hoping to get
  • How much money you are willing to put into your project
  • What parts you've already considered, if any.
Members will help make recommendations and design assistance is generally good. They won't do all the work for you though so you must put in the time and come back with additional questions.

Make sure to have a look through the DIY EV Wiki, as much repeatable information is held there. If you make a discovery or want to help spread the knowledge you've obtained, please contribute. All registered users can add and edit existing wiki pages.

Once you've got your plan down and have started the build, head over to Technical Discussion to get into details of wiring, mounts, fabrication and any problems you've encountered. More savvy users will be able to assist you with your technical needs there.

If you're looking to build a much faster car or are trying to squeeze more bang for the buck out of your newly converted EV, post about in Performance Discussion.

If you're building or converting a motorcycle, bike or other two or three-wheeled vehicle, a good place to start would be in the Electric Bikes Forum.

As for parts and additional services, there are Classifieds, eBay auctions, and a Vendor Forum.

Good luck with your conversion!
 
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#74 · (Edited)
Re: I want to build an EV! Where do I start?

Riaan
"...as cheap as humanly possible"........means you will be using a DC Motor & Controller..........AC Motors & Controllers are not cheap.
Also you will be building it "clutchless" vs the more expensive "clutched" design.
The voltage (number of batteries) of your system will depend on what speed & range you hope to achieve. Basically low voltage = lower top speed and lower range. Higher voltage = higher top speed and higher range.

Using that Microbus you have plenty of room for batteries. And again basically higher voltage = more batteries = higher cost.
Heres an example you could look at:
www.evalbum.com/2843
Also bear in mind that whatever voltage you choose for your battery pack....the "onboard generator" must match that voltage. You can't charge a 120v battery pack with a 12v generator.
 
#75 ·
Re: I want to build an EV! Where do I start?

Thank you so much for the information you shared with me, especially the link to fred's page. Absolutely brilliant.

Just one question, As I stated, due to distances I need to travel I will be powering the vehicle with a built in power generator. Now all generators are rated in KVA, how do I get from KVA to the point where I know if a generator is powerfull enough to power my motor?

Thanks again for the info
 
#76 ·
Re: I want to build an EV! Where do I start?

Riaan
I'm not a Hybrid person so probably not the best source of knowledge on that question. I suspect that your onboard genset will not directly power your electric motor but rather feed your battery pack as you drive. So your choice of generator may depend more on the specs of the battery pack than the motor itself.
Anyway here is a link for converting KVA -


http://www.powerstream.com/VA-Watts.htm
 
#77 ·
Re: I want to build an EV! Where do I start?

I hear you, again thanks for the additional link, much appreciated.

I would prefer to have pure battery power, but I commute 250 kilometers ( 156 miles) per day adn do not have any recharing point / facility during the day. I thus have no option but to go for hybrid. From your knowladge, would you think that there will be a problem supplying the motor directly from the genset ? as that is basically what I have in mind......

Thanks again
 
#78 ·
Re: I want to build an EV! Where do I start?

That technology may exist but I would think it may be more expensive.
It's much easier to supply the battery pack and let the pack supply the motor in much the same way as many production hybrids.
 
#79 ·
Re: I want to build an EV! Where do I start?

That technology may exist but I would think it may be more expensive.
It's much easier to supply the battery pack and let the pack supply the motor in much the same way as many production hybrids.
but what the rate of charge/discharge? would it have enough time to recharge on the go?

the aspect - efficiency of drivetrain, supplying power from energy source to the wheels - ICE engine works nice and steady - under variouse and extreme load (average on overload /underload)

electric drivetrain (transmission, CVT) should have a lot off advantages compare to other mech. or hydrostatic drives

Question: who can give links to info on this type of hybrid - not production, but self-built, from scratch, info on builds, data, calculations?

thank you
 
#80 ·
Re: I want to build an EV! Where do I start?

I have an 89 Hatchback 5.0 mustang and I want to convert it to ev. I need to know what to buy and the basics of how the kit would mount up. I have fairly good automotive experiance, some fab experiance and people who are good at welding and fab. lacking in electrical exp. lol but a very quick to learn. Approximate cost for a car that can maintain 80mph for daily driver? Any help would be much appreciated!
 
#81 ·
Re: I want to build an EV! Where do I start?

I have an 89 Hatchback 5.0 mustang and I want to convert it to ev. I need to know what to buy and the basics of how the kit would mount up. I have fairly good automotive experiance, some fab experiance and people who are good at welding and fab. lacking in electrical exp. lol but a very quick to learn. Approximate cost for a car that can maintain 80mph for daily driver? Any help would be much appreciated!
How much does your Mustang weigh?
What is it's CDa?
How far do you need to drive it between charges?
How fast are you realistically driving it?
Do you want to keep aircon, power steering, big stereo, etc and other stuff that saps energy?
Do you have a budget you need to keep within?

All this will help towards some useful answers.

DC series wound motors will keep things simple.
AC motors will cost lots but will give you regen.
Lead Acid batteries are cheaper but weigh a lot
Lithium is very expensive but is a lot lighter and will give you better range.

Light and aerodynamic cars will give better range and use less power so if you can make your car really light and slippery then that will help.
:)
 
#82 ·
Re: I want to build an EV! Where do I start?

weight: about 3000
cda??? not sure what that means.
like to get about 100 miles 75 min between charges
i can have a lead foot at times :p but 30-80 typically
want to keep stereo with 2 12" subs, air con, all lights and, a few low power led's in interior (only on at night when i feel cool lol)
i plan on doing this over an extended period of time, so budget is not a huge deal. just need an approx. cost of materials. im not trying to make it a drag car, But! i would like to look impressive if a race should just so happen to come my way lol.
i plan on doing a weight reduction, including rear seat, no spare, etc...
 
#83 · (Edited)
Re: I want to build an EV! Where do I start?

here's an estimate -
To get 75-100 miles per charge on a 3000lb vehicle you will need a 144v system using Lithium Batteries (LiFePo) with a minimum AH rating of 160 or possibly more.
So for a mere $9,000.00 you could purchase just the battery pack.

Check the "Garage" here on DIY to find vehicles of similar weight.
 
#88 ·
Re: I want to build an EV! Where do I start?

Hi, all.

I'm brand new to this site. I'm hoping to do a conversion as a senior project for my degree. I'm just starting the program and my senior year will be starting in Fall of 2011, so I'm in the extreme early stages of planning / feasibility study. I want to make it as nice as I can afford, but I also will need to be building a lot of the pieces myself in order to satisfy the project requirements (in theory the classes I'm taking over the next year and a half will equip me to be able to do so).

My favorite car is the Opel GT (the old kind) and I would love to convert one. Has anyone on here ever converted one? I'd love to hear everyone's thoughts on this. I'm going to be trying to learn everything there is to learn about the process from places like this, and hopefully I can have some good level of expertise by the time I'm ready to start.

Cheers,

Paul
 
#89 ·
Re: I want to build an EV! Where do I start?

My favorite car is the Opel GT (the old kind) and I would love to convert one.
GREAT style... but really old! you'll end up probably putting as much into mechanical re-furb as the electric part. Also very small, very light (which is good), but also not rated to carry extra weight.... which means you'd HAVE to go with LiFePO4 batteries for space and weight considerations; which drives the initial price up considerably, but it better in the long run.
 
#90 ·
Re: I want to build an EV! Where do I start?

Thanks for the reply. I know that since it's old there will be a lot of work. I don't mind putting work into it. My classes will be divided between electrical engineering and mechanical engineering, so I'll be needing to work on a broad range of things to satisfy the requirements. The trickiest part will be being able to afford it. I don't mind putting a ton of work into it though.
 
#92 ·
Re: I want to build an EV! Where do I start?

That's a great idea. I've already been thinking about the fact that some kind of subsidization would be great. I'm making this stuff my career, so I just have to convince the government that it would be a good investment :). I was also thinking about corporations. The GT is a head turner, and perhaps some companies would be willing to sell me some parts at cost in exchange for slapping their name on it somewhere. My goal over the next year and a half, before I start the year long project, is to make an extremely detailed plan so that such entities would be more likely to take me seriously. Then again, maybe it's all a pipe dream :)
 
#94 ·
Re: I want to build an EV! Where do I start?

can your guys put up a post that explains what some of the shortened terms translate to... i.e. DoD?! I have absolutely no idea what it is, but it seems like its quite important for calculating range figures...
DoD is Depth of Discharge.

Basically it is how much of the battery capacity you will realistically use without damaging or shortening the life.

For example, lead acid batteries are generally looked at as having a DoD of 50%. That means that you would only use 50% of the energy that the battery could theoretically hold. So you would determine how much energy you need for your vehicle to do a certain range and speed and then double it to get your pack size.

With LiFePO4 you would generally look at around 80% DoD so you could use 80% of the energy in the pack resulting in a smaller capacity pack to do the same work as the larger lead acid pack.

This does not mean that you couldn't use 100% of the energy in the pack but to do so could cause irriversable damage or shorten the life of the batteries.
 
#96 ·
Re: I want to build an EV! Where do I start?

hey guys !
So Here is my first post here and here is a list of what I am looking to do.


I have a 1971 vw bus that i want to convert.
I can fab up anything and wiring is a snap ...
I would like to get some serious mileage out of this and money isnt to much of an issue..
motor : Net gain warp 9
controller: Netgain warp core controller
clutchless mounting..

Here is the real question
Batteries?
AGM?
Lithium Iron Phosphate?
12volt? 6volt?

I would like to go up to 120 volts or maybe even 144.
what would be the very best choice?

I realize that the bus is a large heavy "box"...so any hepl is awesome.
thanks-
 
#98 ·
Re: I want to build an EV! Where do I start?

if you want max range, go for 200ah LiFePO4, if you wanna go real far, then you could consider something wild like two banks of 160ah in parallel. probably 144 or 156 volts, although when you get over 120v 'all the little things' get more expensive. Hmmm, perhaps two banks of 120v (38x 200ah cells) might be a good compromise, but maybe too expensive? You'll probably need at least a Warp 9 and a controller able to dump 500+amps..... so a curtis 1231, or zilla.
 
#99 ·
Re: I want to build an EV! Where do I start?

hey guys thanks for the info-

so I am looking at using 160aha LiFePO4 batterys...
the net gain controller ive picked is good for 750 amps.
i going for 144 volts.

do you think the extra cost to go to 180 aha is worth it? [another 2k?]

and what would the best way to determine estimated mileage be?

thanks
 
#101 ·
Re: I want to build an EV! Where do I start?

G'day people!

I wish to convert my 1999 Mazda 121 (DW Demio).

I need a range of at least 200 km (120 mi)

I will be cruising at 110km/h (55mph) most of the time with some stop/start at either end of the journey.

I am interested in going ac using a Siemens 6SV long with one of the 67kw liquid cooled motors to match.

My main questions regards batteries - I am considering a 300V 26kw/h pack of the A123 prismatic cells - will this be enough? Can someone give me an idea of cost for my project?

Any feedback would be very much appreciated.

Cheers,

Chris.
 
#102 ·
Re: I want to build an EV! Where do I start?

I need a range of at least 200 km (120 mi)

I will be cruising at 110km/h (55mph) most of the time with some stop/start at either end of the journey.
...considering a 300V 26kw/h pack of the A123 prismatic cells - will this be enough?
I don't think this is going to be enough.... at 55mph you would be VERY lucky to consume less than .3 kWhr/mile; so a 26kWhr pack is probably going to get you 75 miles or so.
 
#110 ·
Re: I want to build an EV! Where do I start?

I have a nice and straight '84 Pontiac Fiero with a tired 4 cyl engine. I think it would make a great EV with a bit of work. Here's my general plan:

50 mile range, capable of 50~55mph

Use existing manual transaxle, retain clutch.

The Fiero looks like it can hold 12 decent sized batteries without too much bother, perhaps more but the weight would get a bit much.

No AC/heat. Power brakes from an old electric ABS pump/accumulator setup found in some Chryslers and European cars (I had it in an Alfa Milano).

My big question is:

I work in a plant where we make transmissions, and we will be disposing of a lot of equipment very soon. These machines have large AC spindle motors and VFD's to control them. How do I determine if any are suitable for EV use?

I need to do this on the cheap. I am a mechanical engineer and comfortable around electricity, but not the best at figuring out what is needed. If I could scrounge a motor and VFD, then get a deal on some batteries I think I will be able to pull this off. If not, I guess the 4 banger gets an overhaul!
 
#111 ·
Re: I want to build an EV! Where do I start?

I've been doing a little research on this subject. I think my 72 vw bu would be a very nice commuter car. lots of room for the batteries and still have room for me and my kids.
I live in eastern washington, so heat would be nice unless you don't drive your ev's in the winter (i'd like to know what you guys do)
I'm pretty good mechanically it's the electrical stuff that fries me. fab skills...ok

here's a thought.... hot vw's feb09 issue had an article about a bug that had a/c with the compressor powered off the motor. what if you ran an alternator instead???? would it help increase range or fry the batteries??
 
#114 ·
Re: I want to build an EV! Where do I start?

my 72 vw bu would be a very nice commuter car. lots of room for the batteries and still have room for me and my kids.
sounds great... manual tranny?

... heat would be nice
no problem... ceramic heater core in ductwork, or even circulating antifreeze thru hottub heater core.... all possible, just takes a little extra juice. dont forget to heat the battery boxes, as they don't like cold either.

I'm pretty good mechanically it's the electrical stuff that fries me. fab skills...ok
90% mechanical = 10% following electric schematic. no problem.

a/c with the compressor powered off the motor. what if you ran an alternator instead???? would it help increase range or fry the batteries??
there are options for running a/c...... alternator is not one of them. ;) trying for regen on a dc motor is hard and complicated, regen on an ac motor is expensive. better just to buy a little more battery and run simple dc system.
 
#112 ·
Re: I want to build an EV! Where do I start?

I've been thinking about doing an EV conversion to my '96 VW GTI. I would like 50-65 miles on the charge, and a possibility of 60 mph. Eventually, I'd like to use solar panels to run all electronics. A/C would be a plus, this florida heat is unbearable at times. I am a german car mechanic of four years, with minor fab skills. Not very familiar with electric motors but willing and able to learn. Perferably, I would like this to be a budget friendly build, but i know thats not always the case. Thanks for any info and comments.
 
#113 ·
Re: I want to build an EV! Where do I start?

I've been thinking about doing an EV conversion to my '96 VW GTI. I would like 50-65 miles on the charge, and a possibility of 60 mph.
anything over 40 mile range you are talking LiFePO4 cells.... perfectly doable, just a higher ante to get it rolling. less expensive in long run.

Eventually, I'd like to use solar panels to run all electronics.
put the PV on your house.
better tax deal, and not enough room on a car.

A/C would be a plus, this florida heat is unbearable at times.
doable, just requires a little larger battery pack and about $600-750 more stuff.

sounds like about $12k in parts. ;) W.a.g.
 
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#115 ·
Re: I want to build an EV! Where do I start?

VW is a good choice to convert. Old or new. Welcome.
Thanks for the welcome, good to hear that I can convert my VW. I'm wanting to start with my GTI but eventually want to build an EV VW Transporter, similiar to yours. I'm going to check the website listed on your thread, will this give me a better idea on the conversion?
 
This post has been deleted
#116 · (Edited)
Re: I want to build an EV! Where do I start?

i did not do the Transporter. It was an idea but the one I purchased I sold. If I can ever afford an old Split Window Microbus I will convert it. But to buy a nice one that is not a rust bucket will cost at least $25,000 before converting it. OUCH. Not quite in my budget range yet.
WOW thats a hefty starting point! I like the website you have posted. It was very informative and I got my wife hooked with the vid of the white and yellow bus. She absolutely loved it. I will be doing some more research and will be posting up soon. thanks and are there any other EV VW sites?
 
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