# 94 honda civic conversion



## heynow999 (Mar 2, 2008)

HI Jon

What you do is take your watt-hours and divide it buy your voltage. Say you go with 120 volts. That would be 24,300/120=202.5 Amp Hr

So you would need a 120 volt pack that gives 202.5 Amp Hr. You could use 24 Trojan T-145 6v batteries. They are 72 pounds each, so thats 1728! LBS of batteries. It quickly becomes obvious the limitations of lead batteries. I really don't want to discourage people. I am on this forum because I firmly believe in EV's. I am working on my first one in my driveway right now.

Here's what I am aiming for. I want a 30 mile range at 50 mph. I am using a Saturn. I figure 250WH/mile x 30 x 1.35= 10125. 10125/72 volts = 140.625 AmpHr. I think I can do this with 12 t-105's which are 62 LBS each. I put 6 in the front and 6 in the back and that pretty much equals the weight of a full gas tank in the back and the engine and other components that were removed in the front.

I just took a look at the kit you linked to. That's a really light car they show. Also, I don't like the clamps they show. I used to drive a tow truck. Many times I would get a car that wouldn't start with those type of clamps on the battery. They become loose over time. I would wiggle the wire and get them to try it again and it would usually start. What a nightmare that would be in an EV with 36 of them. I am not saying don't buy the kit, just don't use those clamps.

Good luck


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## fire92658 (May 14, 2008)

What is the 1.35 factor you guys are using? where does that number come from? thanks


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## mattW (Sep 14, 2007)

You multiply by 1.35 for lithium ion batteries (to compensate for peukerts getting 0.95 for every Ah and 80% DoD) or by 2.25 for Lead Acid (peukerts is 0.55 and 80% DoD).... 96V is pretty low for a car that size, I'd run 120 to get highway speeds comfortably.


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## MitchJi (Dec 14, 2007)

Hi,

This might give you some help (he also sells a DVD):
http://budget.net/~bbath/CivicWithACord.html



> IF YOU HAVE A 92-95 CIVIC (any style) WITH HIGH MILES, BUT A GOOD BODY and STRAIGHT FRAME THAT YOU'D LIKE TO SEE CONVERTED, PLEASE E-MAIL ME. BLOWN ENGINES PREFERABLE. MANUAL TRANSMISSION ONLY.
> 
> DO YOU HAVE A BACKGROUND IN ELECTRICAL ENGINEERING, WELDING, OR AUTOMOTIVE MECH/TECH in general? I have a 45 minute video, featuring CivicWithACord (sedan), a '92 Civic (hatch) conversion by the individual who I based my rig on, and a 95 del Sol. It is available for $23 incl. shipping.The cost basically covers postage, my time/materials, plus a donation to defray the cost of this website and furthering EV resources such as the powerpoint presentation (below) and online conversion overview. It's a good deal, as it's loaded with tips that you can only learn from experience. Please specify DVD-R, or VHS. Remit funds via Paypal to bbathatbudget.net, or personal check. For more information, call me at 541.472.1115, or e-mail me at civicwithacordatyahoo.com
> 
> ...


Best Wishes,

Mitch


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## Qer (May 7, 2008)

jonsmith said:


> And then the motor has 96 volts and the controller has 120 volts so this would mean a nominal voltage of 216 volts. So this means 112.5 or 113 Amp-hours. So then I would probably use 12 volt batteries to save space and this would mean 18 12-volt batteries. Is this correct?



Ok, this confuses me BIG TIME. Either you or I are, at the moment, confused and I think it's you. When you're talking about 96 + 120 = 216 it sounds like you've misunderstood how things work. If it's me that has misunderstood you, I apologize if I sound patronizing.

If you have a 96 Volt motor you tell the controller to feed it 96 Volt. What you feed into the controller doesn't matter as long as it's not below 96 Volt (otherwise it won't be able to feed out 96 Volt since it can only step down) or above maximum voltage for the controller.

Maximum voltage for, for example, a Curtis is 144 Volt so higher voltage in the battery pack than that would fry the controller. The Zilla comes with maximum voltage of 144 or 375 (I think) Volt depending on model, but they can also be limited to only feed the motor with 96 Volt.


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## ga2500ev (Apr 20, 2008)

Qer said:


> Ok, this confuses me BIG TIME. Either you or I are, at the moment, confused and I think it's you. When you're talking about 96 + 120 = 216 it sounds like you've misunderstood how things work. If it's me that has misunderstood you, I apologize if I sound patronizing.


You're right. The OP does misunderstand how the controller figures into the system.
]quote]If you have a 96 Volt motor you tell the controller to feed it 96 Volt. What you feed into the controller doesn't matter as long as it's not below 96 Volt (otherwise it won't be able to feed out 96 Volt since it can only step down) or above maximum voltage for the controller.[/quote]

Actually the controller doesn't step down the voltage. All EV controllers operate with PWM (pulse width modulation). Fundamentally a controller is just a humongous on/off switch that sits between the battery pack and the motor. Switch it on, the motor runs, switch it off and the motor gets no power.

Now if you turn that switch on and off fast enough the motor gets pulses of power. The longer the pulse, the more power the motor gets and the faster it spins.

The overall effect of pulsing the motor is that the average power over time depends on the ratio of time spent in the on and off state. However whenever the switch is on, the motor is getting the entire voltage of the battery pack.

It's done this way because it's more efficient to give the motor the full voltage of the pack instead of actually stepping down the voltage and feeding that continuously to the motor.

So the voltage of the controller is the maximum voltage that you can run through it without burning up the controller. As long as the battery voltage (96V in this case) is less than the controller voltage (120V) then you're fine.

As you can see getting 60 miles is going to be pretty tough to pull off in a cost effective manner.

One way to help you pack is to up the voltage. The amount of power you can pull from a battery depends on the rate that you draw that power out. It's known as the Peukert effect. So if you drive a battery hard, it'll give out faster than if you pull power from it more slowly. The end effect is that since power (measured in watts) is volts x amps and that (effectively) the volts on a battery is fixed, that the only way to pull less power is to lower the number of amps that you pull. The only way to do that and get the same amount of power out is to up the voltage.

Take your original pack of 24,300 W. At 96V you'll draw out power at 253A. But if you up your voltage to 144V the pack will draw power out at 168A. But because you Peukert, you'll actually get more total power out of the pack at 168A than you will at 253A.



> Maximum voltage for, for example, a Curtis is 144 Volt so higher voltage in the battery pack than that would fry the controller. The Zilla comes with maximum voltage of 144 or 375 (I think) Volt depending on model, but they can also be limited to only feed the motor with 96 Volt.


Which model of curtis is 144V? I just checked Ebay and most of the 1205 and 1204 controllers they show there are listed at 36-48V.

ga2500ev


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## Qer (May 7, 2008)

ga2500ev said:


> Actually the controller doesn't step down the voltage. All EV controllers operate with PWM (pulse width modulation). Fundamentally a controller is just a humongous on/off switch that sits between the battery pack and the motor. Switch it on, the motor runs, switch it off and the motor gets no power.


Details, details. It's just AC with a very curious wave form and an extreme DC-bias. 



ga2500ev said:


> Which model of curtis is 144V? I just checked Ebay and most of the 1205 and 1204 controllers they show there are listed at 36-48V.


Gav is using the Curtis 1231C and I think that's rated max 144 Volts.


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