[youreakirk]

Hey everybody! I appreciate the site, it's really the best one I've found and has been a lot of help in my preliminary planning for my conversion.

I recently bought a 5 speed 1986 Honda CRX Si to convert to an electric car. I have no previous experience with cars, but I learn quickly, and I have a buddy who is helping me who is slightly more knowledgeable and also knows how to weld. I also have access to a machine shop for free.

My ultimate goal is approximately 35 miles per charge, without any highway driving. I would be fine with a maximum functional driving speed of 45-50 mph, with the top speed (which I wouldn't really ever use) hopefully over 60 mph. I realize that is a somewhat high goal that will probably require lithium batteries, which I currently am saving for, but until then for the car to be useful I need a 15 mile range to get to school and back (I could possibly use an old lead pack until I have enough money to switch to lithium).

I'd like to spend no more than $3-4k on the car. I bought the CRX for $680 (delivery included I might add) but it came with two working engines, recently replaced windshield, new axles and struts, and several extra parts I will be able to sell to reduce my initial cost.

I am considering the DIY Open ReVolt 144v controller which is $600. I will investigate used controllers however at my local EV Club meeting, and I haven't really looked at commercial ones but I know they're expensive. I would like to go the forklift motor route as opposed to a new one. I should be able to fabricate my adapter plate for a low cost.

I figure that this leaves most of the rest of my money for batteries. A friend who did a conversion recently recommended I skip lead acid, as "they sucked." They are really expensive though, but I would just love a 35 mile range. (I'm thinking around 144v x 50 Ah?)

Right now, my buddy and I are cleaning and restoring the CRX as it has some rust and needs some slight bodywork (and a paint job).

So here are my questions, in no particular order: What's the best way to remove rust? Paint the car? What's the real deal with lead vs. lithium? Forklift motors? The Open ReVolt controller? Is a 35 mile range realistic for under $4k? Clutch vs. clutchless?

Thanks so much!

[drgrieve]

Welcome.

lead vs. lithium - lithium
Forklift motors? - possible - 144V might require modifications (eg advancing brushes / brush replacement / rewiring). Many folks on here has gone down this path.
The Open ReVolt controller? Yes [or look at a soliton jr $1800 if you can strech]
Clutch vs. clutchless? Clutch

35 mile range at 80% DOD. CRX is a very light car lets be ambitious and say you can get 200 wh/mile.

35 * 200 / .8 = 8750 kwH.
8750 / 60ah / 3.2V = 46 batteries
45 * 3.2 = 144v

Look at paying 1.20 to 1.25 per ah for Calb (not including delivery). Not sure on price on Sinopoly. Based purely on the spec sheets Sinoploy is a better battery but you'd have to get them from China (not aware of a USA distributor).

So 60 * $1.20-1.25 * 45 or 46 = ~ 3300 to ~3500.

Doable for an around the town car.

Note when designing your battery boxes and/or layout, leave room for paralleing the cells - so if later on you want to spend another $3500 you can double your range and power. It's better to parallel the cells as opposed to putting modules in parallel. Perhaps something to read up on if this doesn't make any sense.

[youreakirk]

Thanks! What are the pros/cons of maintaining the clutch? Is it difficult to incorporate with the electric motor?

[youreakirk]

Updates!

We have completely de-ICEed the car. Also we recently acquired three electric forklift motors, ample (ha) power cabling, and a control system from an old forklift for FREE!

We're gearing up to start adapting the drive motor of the forklift (other two are hydraulics) to the transmission and machining the coupler.

Additionally, due to monetary/time reasons, we have downgraded our expectations. New requirements: 30-35 mph, 12 mile range.

We'd like to use some used golf cart batteries at a low cost and I hope this will get us to our goals. However, I still have a few concerns - the motor is only rated to 24v and is 7" in diameter. It is an extremely light car, but I hope the motor will be enough. It was hard to beat the price...

I've seen 24v motors used in a few conversions, how safe is it to overvolt them? And thoughts on voltage or other battery pack specs (lead acid for cost) for the aforementioned goals? Also, is there anything we need to do before we bolt together the motor and tranny to still use the OEM spedomoter and tachometer? Keep in mind we are high school kids with small albeit expendable incomes from summer jobs - we are trying to do a "rat rod" conversion that will get us to school and back.

We also decided to go clutchless in the interest of time and money - I can already shift (up and down) comfortably in an ICE car without the clutch.

Thanks! Any advice/comments/critiques are much appreciated!

Also, here are some pics!

Before de-ICEing


The lift!


The motors


The drive motor


The external shaft drove a gear in the forklift tranny


Power connections


Info plate


Cables!


Car tranny and clutch plate


24v control system with wrist throttle potbox for forklift

[youreakirk]

The old ICE. Trying to sell this sucker, any tips?


Engine bay!

[drgrieve]

Try cross posting the information for the forklift motors (all the info on the nameplates) to a new thread in the motor section with a link back to here.

Someone there should be able to help you.

There is also a massive thread there all about selecting a forklift motor and the difference between rated voltage and the maximum voltage you can run them at.

[hondaguy72]

Originally Posted by youreakirk

The old ICE. Trying to sell this sucker, any tips?


Engine bay!

The people over at redpepperracing.com would love to take the extra bits off your hands. Be aware that prices are not very high for these motors.

[youreakirk]

Update:

Progress is being made! I recently bought a contactor rated for 48v and a 250a 48v curtis controller. The adapter plate and coupler are almost complete, and I drew a preliminary circuit diagram for the car. No idea on batteries yet, people seem to not like returning my calls.

I have a few questions: How does one wire a curtis controller? I'll post pictures of it, but B+ and B- are fairly self explanatory, but for some reason I thought the controller was just in series with the battery pack, so there would only be a need for a B- and a M-, not a B+ too... hmm.

Here's my first sketch of the basic circuitry:



My only experience with DC circuits is my high school physics class last year... I don't fully understand grounds and the whole thing may be way off but that's why I'm posting it here! To hopefully get some input...

Thanks everybody! I'll put some pics of the controller, contactors, and adapter plate/coupler up soon.

[youreakirk]

Pics of controller and contactor - how do I work/wire the controller?

[MN Driver]

You could probably push 48v through the 24v motor, just check for any brush arcing and if there is any you may need to advance the motor to stop the arcing so it can handle the higher voltage. In reality 48v may not be a problem. I've used little DC appliance motors and overvolted them without much trouble.