John Williams' Daihatsu Electric Car · 4 May 08
John is one of the growing number of EV owners in Australia. He runs the website EV Australia (link at end of article) and has been providing useful feedback on this site via comments for some time now. He is putting the wraps on his current EV conversion, based on a two seater Daihatsu Charade (it wasn’t always a two seater: he removed the back seats for batteries).
Other specifications for the EV Conversion:
Controller – ZAPI H2 120V 600A with regenerative braking
Motor – Advance DC 11kw
Charger – Zivian H3
Batteries – 10 × 12V 185AH lead acid total of 550kg (1,200lbs)
A look under the hood, or “bonnet” as John would say.
I took the liberty of taking the photo on the left and marking up the components. John will have to jump in and correct me, as I wasn’t quite sure on the DC-DC and really guessed that the far left item was a circuit breaker. John sent along an annotated photo which better shows the parts and includes the ACC battery. What I thought was a circuit breaker is the reversing relay (double throw, double pull?). One of the benefits of having a regen controller like the Zapi is that you get electric reverse as a bonus. BTW, the “wart” on the controller is a mod that steps up the max voltage capability from 96 to 120vdc.
Perhaps at some point we can whip up a rough schematic as well, especially since this EV features regenerative braking, which changes the wiring.
As with any EV conversion there’s often a learning curve or misunderstanding and John’s was no exception: “I didn’t realise that the ZAPI used full pack voltage to drive the contactors and I used ones with 12V coils. To cut a long story short I cooked one contactor and the logic board. I think I’ve narrowed the damage down to a track, 3 diodes and a driver transistor. Hopefully I can repair it otherwise I’m up for a new logic board or controller.”
These two photos show the damaged area of the controller’s logic board. John, being an industrious fellow, managed to fix it.
“Replaced 3 diodes, a power mosfet and a bit of jumper wire for the burnt out track totaling $5. It’s now working, a lot better than $999 that a local place quoted me. In fact I got everything together and took the car for a short test drive last night. It works!!!!!!!”
The Zapi H2, since it is a regen controller, is wired directly to the relays so as to control which relay is on and when. That was the case with the Zapi H3 that was used for a bit on my first EV as you can roughly see on the wiring diagram I put together back then.
And now for the big challenge: where do you put a thousand pounds of batteries in a small car like this? John got two of them up front with the motor and electronics and the other eight are now “passengers” in the back seat and trunk. I really like the battery box and asked John about it:
“Battery box was made by my neighbor who is a steel fabricator/sheet metal worker. It’s made out of aluminum of cuts and took him about an hour to bend and weld up while I fixed his office network. It will have an aluminum lid once he gets around to making it for me. It’s not hard IF you know how to weld aluminum. Being aluminum I have to coat it with an acid proof paint or give it a rubber lining to get to pass the licensing inspection. Underneath it is a steel frame to give it support which will be bolted to the floor of the car. I’ll take a picture of that when I remove the batteries to bolt everything in. At the moment they are just sitting there and everything tends to want to join me in the front seat when I stop.”
As for lining a few folks in the past have suggested using the thick rubbery stuff they use for truck bed liners. You can buy it in spray cans and in half/full gallon cans to spread on manually. Click the photo to see one of the types I found on Amazon.
The batteries are Supreme (PDF) deep cycle CR 185’s. They cost AU$3000 for 10 plus AU$200 shipping from Sydney to Perth. They are REALLY heavy at 55kg (121lbs) each.
A shot of the interior wiring in-progress. John can jump in with more details on what he’s using for instrumentation.
As mentioned earlier the H2 is a regen controller and John has wired it to eventually use the regenerative braking but hasn’t yet tried it out. One thing that needs to be done first is to change the advancement of the electric motor brushes. Most DC motors come with the brushes “advanced” a bit, which is fine if you only use the motor to generate thrust. Once you start using the motor to generate electricity this advance is the “wrong way” and causes the brushes to arc. ADC motors can be reconfigured and it is suggested that they are put back to zero advance, which strikes a better balance between driving and regen, saving wear and tear on the brushes.
So far John has driven the EV a little bit, but he’s (wisely) holding off on longer test runs until the battery pack is fully secured. Thanks for sharing John. Be sure to stop by and see John at EV Australia.