# How much can I do with a shoestring budget?



## Keyboard Sounds (Sep 7, 2016)

After seeing reading a bunch of build blogs of guys who made their EV conversions under 2200$, I was inspired to take my own helm but the problem is that, I don't know much about ICE engines or electric vehicles, only electrical experience I have is replacing capacitors of old computers and only mechanical experience I have is changing oil.

I do have a few friends who are quite experienced and knowledgeable with cars (who also dont know much about EVs) which will help me on my project.

And since I don't know what I'm doing, I have a million questions
With a budget under 2200$, what kind of range should I expect? Is a 0-100 kph time under 10 seconds, a range of 50 km and a top speed of 110 a dream with this budget?
Are AC motors not recommended for first builds? 
Are lithium-ion batteries more common than before and are they worth the money?
What kind of a car would you recommend to convert? I have a Golf Mk4 with a blown engine that is waiting to be stripped for parts but is that too heavy?

It'd be nice If you give some advice, while trying to get more information I started reading Convert It by Michael Brown and have Build Your Own Electric Vehicle by Bob Brant on my backlog, so I am open to reading suggestions as well.


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## Duncan (Dec 8, 2008)

Hi
No $2200 is a bit short 
Double it and it is possibly doable

Shopping list
Chevy Volt Battery - $2000
Forklift motor - I paid $100
Controller - Paul & Sabrina - $600

Make your own adapter to fit the motor

Make yourself a Bad Boy Charger - $150

http://www.diyelectriccar.com/forum...-dubious-device-44370p2.html?highlight=duncan


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## madderscience (Jun 28, 2008)

Conversions have certainly been done for under $2200, but usually by people who either have unusual access to parts (e.g. they run a forklift repair shop or something) or they are quite resourceful mechanically and electrically, so they are very good at repurposing parts and/or building their own components like controllers and chargers. Sounds like you are motivated but maybe not quite that far up the MacGuyver scale. (yet)

Your 50km range is probably realistic for a low budget conversion, but the acceleration and top speed are likely to be problematic. Most likely this would be because low budget conversions are usually low voltage, which limits high speed performance.

There is zero reason to go with lead acid these days. Wrecked production EVs like the LEAF and Volt are good sources for battery packs at better prices than new LiFePO4 or Lead acid. However, one of those packs will still eat your entire stated budget. 

The Mike Brown book IMO is dated. Unless it has been updated recently, it still describes the canonical 1995 flooded lead acid/curtis DC conversion. Its a good step by step guide, but describes an out of date design. The Brandt book has been kept more up to date (hoping you have the latest edition). Other than that, your best source of information is clubs and forums like here.

Your Golf is a decent conversion candidate, presuming it is in good shape with the exception of the engine, and it is a manual gearbox. However with EV conversions, weight is (almost) everything so if you are really looking for the absolute cheapest conversion, perhaps sell it and buy the smallest subcompact/micro car you can get, or consider a motorcycle conversion instead. You can do a lot more with a motorbike for $2200 than any car.

BTW since $2200 is such a specific number, I'm guessing thats how much you happen to have available at this moment. I'd suggest maybe wait a while longer while doing some research and learning, and let that budget grow a bit. 

Good Luck.


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## Moltenmetal (Mar 20, 2014)

If you have $2200 available, a motorcycle or scooter would be your best bet. If you're not mechanically and electrically skilled, and want to be, the challenge of a smaller project will get you warmed up but with lower risk cost when things go wrong.

Anyone claiming to have done a real EV conversion project for $2200 definitely got some parts for free and did a lot of work themselves- hard, skilled work- or they have a project which might drive but won't be reliable on the road for long. The Forkenswift guys did their project for very little money, but that's because they were "given" their first battery pack. Batteries are a lot cheaper now that you can buy parts out of wrecked OEM EVs, but they're still the major spend on a real conversion.

BTW now that you can buy a used OEM EV, the only point to doing a conversion is a) for the fun and learning of it and b) to have a unique and cooler than normal custom car when you're done. In my view, that means converting classic or more interesting cars rather than econoboxes.


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## Keyboard Sounds (Sep 7, 2016)

Since building your own components seems to be the way to go to get the costs down and batteries are the main expense.

How stupid would it be to make your own battery packs out of 18650 cells? I see people making them for their bikes.


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## Sunking (Aug 10, 2009)

Keyboard Sounds said:


> Since building your own components seems to be the way to go to get the costs down and batteries are the main expense.
> 
> How stupid would it be to make your own battery packs out of 18650 cells? I see people making them for their bikes.


 Just imagine using up to 7000 cells. How much does one cell cost? How many connections and cells is that to fail?

Look your battery realistically is going to cost more than $2200. I modified my golf cart from factory 48 volt DC to 96 volt AC. Just a very small 96 volt 66 AH battery cost me $2500/ The AC Motor and Controller was another $2400.


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## Matej (Dec 4, 2015)

Keyboard Sounds said:


> How stupid would it be to make your own battery packs out of 18650 cells? I see people making them for their bikes.


There are people on YouTube who seem to think they stumbled upon some hidden secret because they learned that they can scavenge and repurpose 18650 cells out of old laptop batteries and such, but in reality with every cell they add to their collection they are just drawing nearer to inevitably burning their house down during a botched charging attempt.


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## Keyboard Sounds (Sep 7, 2016)

Is trying to salvage dead laptops is more dangerous than getting a battery from a wrecked Volt? Where does the danger come from with the laptop batteries?


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## Duncan (Dec 8, 2008)

Keyboard Sounds said:


> Is trying to salvage dead laptops is more dangerous than getting a battery from a wrecked Volt? Where does the danger come from with the laptop batteries?


OH YES!! - the Volt is specifically engineered for use in a car and is bloody well done

Laptops can catch fire in a computer! - and a car is about a thousand times the load

Specifically the failure mode is one of the 7000+ laptop cells or connectors fails (quietly)
The next charge that failed cell kills its mates (quietly)
The charge after that your charger overloads the rest of the string and they burst into flames


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## evmetro (Apr 9, 2012)

Yea, your budget is a bit light, but congrats on having the desire to do this. It sounds like you have taken some steps to research your goal, and here you are probing this community for more info. In my country, our automobile culture was once much richer with DIY innovation and nice builds, but something bad has infected our culture now. People seem to be losing that desire and proud feeling of building their own EV or custom vehicle. If you want this EV enough, it very well may happen. Keep reading and learning, and you can compile a list of what you will need for your build for when the right opportunity presents itself. Doing your own conversion is good for a man's soul, so I hope this happens for you.


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## EVisa (Jun 30, 2014)

Keyboard Sounds said:


> Is trying to salvage dead laptops is more dangerous than getting a battery from a wrecked Volt? Where does the danger come from with the laptop batteries?


Just imagine where you would prefer to draw 45kW from. Enough said.

Stay safe!

p.s.: the guy tested every single one of them. Not every bunny's game...


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## Duncan (Dec 8, 2008)

I had a thought "a wrecked Volt" - does not imply any damage to the batteries

The batteries in a Volt are in the center of the car in a T shaped module - if the crash has been massive enough to damage that module run away!

Most cars are written off for relatively minor bodywork damage - you want the batteries out of one of them 
The Volt that has crashed into a semi and then fallen 100ft down a cliff is NOT what you want


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## EVisa (Jun 30, 2014)

Amen to that.

Oh, and please, don't start soldering together hundreds of random lithium cells. Apart from safety (you may effectively burn down your house, no joke), doing the physics properly would take you multiple multitudes of time. 

As much as I dislike GM, the Volt pack is something they got right.


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## Keyboard Sounds (Sep 7, 2016)

Ok, let's set aside the fact Volt's batteries are safe because it's well placed and will be good unless the car turned to a pancake, It will likely not be an option for me as the prices here will be worse than US.

Testing thousands of cells is no problem for me, I have time but not the money and isn't it the BMS job to shut down and protect the rest of the system if one cell goes bad anyway?

I understand the safety concern obviously, considering the fact that I'm an absolute newb who got the battery idea from a youtube channel and will never have the engineering talents of GM but, It seems to do be doable without making a death machine?


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## EVisa (Jun 30, 2014)

It is doable, but don't underestimate the challenge...

Weigh carefully what you put into it, and what you will get out of it. You may get your physics wrong and your batteries right, but vice versa means definte problems .


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## mjcrow (Jan 5, 2008)

I see you are in Darwin in OZ, there is a member of the AEVA (Australian Electric Vehicle Association) in Brisbane (from memory) who periodically brings in batches of salvaged Nissan Leaf cells, probably a better option than 18650 laptop cells. Also from time to time cars come up that have been converted previously with lead, but need a new pack to give them a fresh lease of life, they usually sell for much less than the price of the parts.


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## Duncan (Dec 8, 2008)

Hi Keyboard

If you can get the cells free then that may be viable - but my Volt pack cost $1800US
Shipping and taxes (to NZ) was about $500US

You would have to get the small cells for $0.50 to get close to that
AND I got three small contactors and two big contactors plus a ton of useful bits in that assembly


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## Moltenmetal (Mar 20, 2014)

The important part to NOT learn from the YouTube channel is the temptation to charge or discharge these bricks of recycled 18650 laptop cells without a BMS. That is asking for a fire. Being your own BMS when using a bunch of new matched cells risky too, but doing this with mixed used cells is a recipe for disaster, and the people putting this crap up on YouTube are irresponsible.

Larger format cells intended for vehicle applications are a far better choice for a DIY- far more likely to obtain a safe outcome.


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## rmay635703 (Oct 23, 2008)

You can get a fully functional ev off the shelf for that amount of bank
Just buy a comutacar or a Miles zx40

Then as you get more cash upgrade it.

Other option is think evs are about $4000 and up and mievs are $5000 and up.

You don't have to resort to an unreliable dangerous home built system to get on the road.


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## Keyboard Sounds (Sep 7, 2016)

I would rather convert my own car rather than just switch the batteries on someone else's conversion or production, the goal is to have a project, something to do and learn with.

Also with most people saying it's dangerous with the 18650s and how it's not really suited, what can I do it to make it safer and better? Because I have an easy and cheap (below 5 cents per cell) to them and would be great If I could take advantage of my position as it seems like that's how the ultra cheap conversions are made, take advantage of parts you can get.


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## dougingraham (Jul 26, 2011)

Keyboard Sounds said:


> Is trying to salvage dead laptops is more dangerous than getting a battery from a wrecked Volt? Where does the danger come from with the laptop batteries?


Dealing with dead laptop cells is quite a lot more dangerous than dealing salvage Volt or Leaf packs. The 18650 laptop cells are the most dangerous of the LiIon types of cells. The Volt and Leaf type cells are second most dangerous (but you probably are not going to be messing with the cells) and LiFePo4 type cells are the least dangerous type of LiIon cell. The danger comes from having to un-package them, clean up the ends of the cells, and the connect them electrically to their neighbors.

The 18650 batteries themselves are not dangerous unless mistreated. But in almost all cases of mistreatment the cell will go into thermal runaway and catch fire. If it adjacent to other cells those too will catch fire and it is a difficult fire to put out.

Simply shorting the cell for a few seconds can be enough to cause a thermal runaway event.

Can it be done? Of course it can. But a minor mistake like a dropped tool or a blob of solder falling in the wrong place can cause a fire which can burn down your EV and if it is in your garage your house as well.

Plus are you really saving anything? A Volt pack is 16kWh and a Leaf pack is 24 kWh and they are probably in excellent condition. Laptop batteries have been abused and you will need to test every cell. To get the equivalent of a Volt pack you will need approximately 2162 cells and the equivalent of a Leaf pack approximately 3243 cells. This is assuming the cells you get are 2 AH in capacity. This means you need to pay quite a bit less than a dollar each.

You will expend an enormous effort dismantling, testing and assembling these cells. Effort better spent on some other aspect of your conversion project.

Best Wishes!


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## Moltenmetal (Mar 20, 2014)

BMS is essential with these high energy density chemistries. You need a BMS alarm trip on every group of cells in parallel. That goes double if your cells are used, and double again if they are of mixed type or capacity.

Again I suggest that you either get the budget to do your project properly or learn on a smaller project like a bike or scooter, where learning and trying things a couple times isn't devastatingly costly. But even a scooter can burn down your house- you need the safety equipment and the attention to detail and the knowledge to stay safe.


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