# First Conversion - '91 Honda Civic Si



## Duncan (Dec 8, 2008)

Hi Eltyhm

Some rough figures to get you started
Allow for 300 watthours/mile - at 55mph you will probably be a bit less
50 miles x 300 watthours = 15,000watthrs = 15Kwhrs
You normally only use 80% of your battery - to avoid a very short life
So you would need 15 /0.8 = 18.76Kwhrs
At 144v that is 18750/144 = 130Amphour

Now that there are significant numbers of factory built EV about and being crashed the most cost effective batteries are either Chevy Volt or Nissan Leaf 

The Volt pack is 16Kwhrs, the Leaf 24Kwhrs,
They seem to be available from the car breakers for $2000 - $4000


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## Moltenmetal (Mar 20, 2014)

Duncan is as usual, dead on in his assessment.

You will need to read some of the threads in the Batteries forum here to find out what re-configurations of Volt and Leaf packs are possible easily, without going to the extremes that people like Yabert have done. I'm not sure how close you can go to 144 V nominal to be within the limits of the high voltage (1239?) Curtis controller for the AC51 motor, but others have sorted that out already and can tell you off the top of their heads. 

I went with 32 x 180 Ah Sinopoly LiFePO4 prismatic cells in series, giving me 18.5 kWh stored at 105 V nominal, which is within the limits of the 96V (650 A) Curtis 1238 controller used with my AC50 motor. I love my E-Fire but my bank account is still hurting from buying that pack, so I'm babying it in every way I can...

If I were re-doing it today I would be using a Volt or Leaf pack- no question. I'd have to drive down to the US to pick it up though- crashed Leafs or Volts are still rare as hen's teeth here in Canada.

Some here are going whole hog and transplanting an entire working Leaf drivetrain from a crashed Leaf into another, more interesting vehicle. Cool, but fraught with difficulties and compromises relative to doing what you're planning.

Best of luck with your project- keep us apprised by starting a build thread. People here are awesome and give great advice.


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## sholland (Jan 16, 2012)

Just feedback from my own experience converting my 96 Civic... Not sure on your definition of 'fast' but the AC51 may not be as quick as you might like with the extra weight. The AC51 will give performance similar to stock and maybe a little slower. For the same money, a DC motor/controller will get you very fun performance for the same or less money.


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## sholland (Jan 16, 2012)

You may also want to check out these AC150 systems. They are a pretty nice package for the money, though it will require some custom work to fit properly. I am sure they still have some left. They may also be interested in negotiating the price.


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## Elryhm (Feb 4, 2016)

Thanks everyone for the replies.

@sholland
Sorry. When I said "fast," I meant quick acceleration. I'm mostly going to top out at 55MPH, so top speed is pretty negligible. I just want something fun and responsive to putt around town in.
I've also heard DC motors are a lot more work, with the extra mantainence and circuitry needed and whatnot. I'll look more into it.

As for the whole Leaf/Volt thing... Are they really that easy to use? I've heard they have some kinda proprietary BMS on them that only the OEM computer could actually decipher, thus making them a pain the butt for lowly DIYers such as myself.

Thanks again, guys. I'm getting a better idea of where I need to look.


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## Moltenmetal (Mar 20, 2014)

DC is no more difficult than AC, just more maintenance, no regenerative braking and more torque/power for the same dollars invested.

Prismatic LiFePO4 cells are much easier to use than Leaf or Volt packs, but they're also 3x as expensive on average. The after-market BMS solution for them still isn't obvious either, though it doesn't seem to me to be all that difficult.


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## sholland (Jan 16, 2012)

I think they are both great solutions, but if you want quick, A Warp9 with Evnetics Soliton1 has far more HP and torque than an AC51 for almost the same cost.

Here are some dyno plots for the Evnetics Soliton1 and Warp9:
http://evtv.me/2011/03/speedster-redux-and-the-dynomometer-puzzle/

Here are some dyno plots of the AC50, though there are probably some out there for the AC51.
http://evtv.me/2011/04/1955-porsche...38-7501-and-7601-controllers-650-amp-upgrade/

The DC setup is almost double the HP and torque to the wheels. Sure, there's no regenerative braking, but if you aren't driving stop and go regularly, it adds no benefit.

The Soliton 1 is nice, as it includes an internal main contactor relay and precharge. You don't need the precharge resistor with the AC51, but you will need to add an external contactor, so in my opinion, the Evnetics is an easier setup.

I have 15000 miles on mine, and it has been a completely trouble free and totally fun experience!


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## Caps18 (Jun 8, 2008)

Why are you converting a '91 Civic? Can you find the parts to mount the motor to the transmission? Do you have space to put the batteries? Could you spend the same amount of money and get a used EV instead?

Converting classic cars or vehicles that can be used to haul stuff seems to be the ones that are worth working hundreds of hours on to me.


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## sholland (Jan 16, 2012)

Caps18 said:


> Why are you converting a '91 Civic? Can you find the parts to mount the motor to the transmission? Do you have space to put the batteries? Could you spend the same amount of money and get a used EV instead?
> 
> Converting classic cars or vehicles that can be used to haul stuff seems to be the ones that are worth working hundreds of hours on to me.


Seriously? You must be trolling...

Maybe because it's a small, efficient, lightweight platform already, and actually very easy to convert. Everything that is needed to convert is readily available (e.g. CanEV for transmission adapter). I mounted 27kWh of batteries and maintained the full interior. You can't even tell from the inside.

Not many people convert classic cars as they are relatively heavy and not very aerodynamic. Besides, some people just like Honda Civics and CRXs.

Do you also go on hot rod forums and ask why people build build up old Camaros and Mustangs, when they can just buy a new one that performs as well or better?


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## Duncan (Dec 8, 2008)

I agree with Caps
You can't compete with the big car companies - if you are building a car to compete with a Leaf you are just pouring money down the drain

You can buy a second hand Leaf that will be better than anything you can build for less than a conversion

So why are you messing about?
Because you want to? - fine answer!
But another idea is to build a non Leaf - an electric classic or hot rod


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## sholland (Jan 16, 2012)

But I'm not building a Leaf either! I'm building a Honda Civic. The Leaf is tall and ugly (just my opinion), while the Civic (whichever form you prefer) is smaller, looks great and has great handling. Besides, maybe I want to have a say in how it's electrified... Can you get a Quaife LSD for a Leaf? I don't think so... Maybe I want to have more than 110hp, or maybe even 4 wheel drive... I can make it any way I like!

I'm not against converting a classic, but why question a person's taste? Maybe my Honda Civic is my hot rod...


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## Duncan (Dec 8, 2008)

Whatever floats your boat!

Building exactly what YOU want is a very good answer


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## jwiger (Oct 18, 2014)

Some battery 101 for you. Two 3 volt, 60 Ah cells in series gives you a 6 volt 60Ah battery (a 0.18 kWh pack). Conversely, two 3 volt 60 Ah cells in parallel gives you a 3 volt, 120Ah battery (also 0.18 kWh) pack. So if you take a 360 volt, 60Ah Nissan Leaf (21.6kWh) battery pack (which is 48 modules in series) and split in to two 180 volt packs. You can parallel those and have 180 volts with 120Ah (still a 21.6kWh pack).

Actually the newer modules are ~64Ah, so parallel you would have ~128Ah, and they can do a short (few seconds) acceleration at near 10C which means you can get about 1.280 amps, from it. Plus they are half the price of new LiFePo batteries. 

What's your honest budget here? Your battery pack will be your largest expense, hands down, even used. Unless you're only living your life 1/4 of a mile at a time.


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## Elryhm (Feb 4, 2016)

jwiger said:


> What's your honest budget here? Your battery pack will be your largest expense, hands down, even used. Unless you're only living your life 1/4 of a mile at a time.


Well, I was looking at about 4.5k for the motor and controller and about 4k for batteries plus all the other stuff, such as wires, fuses, chargers, etc.
I'm thinking now I might go DC/DC instead to save some money and use the money saved to buy the "ect." parts with.

And for that one guy: I'm not trying to make a Leaf. If I wanted an electric car that's already done, I would have bought one. I want something I can call my own; something that's unique and I can say that -I- did. Any person can throw down some money and buy a car. How many have actually made one?


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## Duncan (Dec 8, 2008)

As the "one guy"
I can report that I scratch built my electric car

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

Building it because you want to is great - just don't delude yourself 

If you use a Leaf or Volt pack you should be OK on those numbers,
DC can be cheap and powerful
My motor and controller cost about $700


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## mons2b (Nov 17, 2015)

Elryhm said:


> Hello, everyone.
> 
> I've been wanting to do a conversion for quite some time now and finally decided to take the plunge. Turns out, I'm more lost than I had hoped.
> 
> ...


Volt pack as per Duncan. Thumbs up.
Motor and controller nice but pretty pricy unless your set on american products and can afford them. Im going to use a 15KW motor and controller from a EV motor factory in China which in your civic would go even faster than in my BMW project . If your interested I can pass you more details. My prototype setup will be 144v and range desires are similar to you.


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