[otedawg]

So, after lurking and reading for a couple years, I've finally committed to building my first EV. I'm an electrical engineer, so all the concepts are familiar to me, but I've yet to get my hands on a high-voltage, high-current system. I'd love comments on my build plans.

Donor car: Rustless 1971 light blue bug
Planned Motor: Warp9
Planned Controller: OpenRevolt
Charger: Elcon HF/PFC1500 (Should give ~10hr full charge from 80%DOD)
Adapter Plate: Order from WildernessEV - nobody seems to be able to beat their prices
Shaft Coupler: WildernessEV
Throttle Box: Curtis PB-6
Contactor: Tyco EV200
BMS: MiniBMS
DC-DC Converter: Still haven't decided - maybe just a solar panel w/charge controller (not currently planning on driving at night)

And now the big ticket item...
30 CALB 130Ah batteries (Those are expensive)

From my calculations, I should be able to get 40mi of range out of these batteries at 50mph. I really like that idea - I'm planning a single bank of batteries behind the rear seat, and 30 is the max I could fit back there.

I'm going with a 96V system for future upgradeability. I originally planned to just go with the WildernessEV kit, but I'm thinking I can piece something together for around the same price, and I've heard on here that those kits are junk.

I'd love to hear comments from people about my build ideas. I'll post my battery box design tomorrow if there's any interest - I'm planning on buying the parts and putting it together sometime this week.

I do have one question - from what I've read, the biggest part of builds is the prep-work (building battery boxes, running cables) is that true? How long should I plan on working on this car before it's in a drivable state?

[Ziggythewiz]

You'll want more than 96V, is there a particular reason for only using the rear storage shelf? What do you have planned for the front trunk space?

I'm not sure what you consider prep-work...vs conversion work?
Expect everything to take about 100 hours, give or take 50.

I like your DC-DC idea...if you're using lead for your AUX you don't even need a charge controller.

[otedawg]

Lowcrawler,
It doesn't matter how I run the numbers, I'm still getting that I can only fit a max of 40 CALB 100AH cells. I'll try measuring again, but I'm still wondering how you did it. (Without stacking cells) Do you have pictures of your battery bank that you could post?

Thanks,
Josh

[lowcrawler]

Oh, sorry... my photos are on a different computer. I'll see if I can get a video up tonight...

I stacked them. The entire box is 12 cells wide, 2 cells tall, 2 cells deep. a 3/4"x3/4" piece of vinyl 'wood' sits on top of the lower set of cells and the upper set of cells sits on that. it fits with about 1/2" clearance on the top/back before the rear window glass. There is about 4-5" of space on the sides and the back seat back actually rests on the box when 'up'.

Obviously this forced the use of the centralized BMS, and if I ever need to mess with the lower set of cells I need to remove whatever is on top first... but I hope to not need to mess with them often.


You could simply go with your 40 back there and then run a cable up to the front boot. Getting a cable from the back to the front of the car is actually really pretty easy... just use the heater channels. The hardest part is where the channel takes a 90 degree turn at the front fender. Only took me about 2 minutes to run my first 6ga wire through there...

[Ziggythewiz]

Getting 2/0 to make that corner was a real pain...

Why not just use the engine bay for the extra cells? There's a ton of space back there. The only reason I'm not using it is because I'm still on lead, and didn't want the acid cloud right by the motor/electronics. With lithium there's no reason not to stuff that back.

[lowcrawler]

Originally Posted by Ziggythewiz

Why not just use the engine bay for the extra cells?

Not a bad idea if you only need a few extra. You could put them 'hanging down' from the left and right of the motor and still have plenty of room for the controller, charger, tps, and other items back there... That engine bay is deceptively large.

[Ziggythewiz]

I was thinking more of a bridge between the flats on each side, with a hump over the motor.

Here's an example of the space back there. If this guy can get 4 big floodies back there (with room for 2 more) you could stuff 40-50 100 AH cells back there along with your controller and junk.

[otedawg]

Just picked up the material for my battery box. I'm just using heavy duty plywood for the one behind the seat. I'm planning on painting it with primer and rust-oleum, and having a drop-in lid for it.

Should be pretty easy.

I also got what looks like great candidates for rear boxes - mailboxes. I'm going to cut the end off, and have 2 enclosed mailboxes under the hood with the controller, motor, and cooling. I'll be putting 30 batteries behind the rear seat in the box, 5 in each mailbox, and the last 4 under the rear seat across from my lead battery.

I'm planning on using a hole saw to cut the hole for the cabling in the battery box, and run some 2" abs to the rear of the car. I may even cool the box with 2 computer case fans blowing through separate pvc.

[otedawg]

So - I built the battery box, and it just barely fits. It looks like I may have to move the rear seat locking mechanism about 1" in order to have this perfect. No big deal.

I painted the box with rustoleum silver paint, and started in on the dash of the car. The dash is a bear to take off - I still haven't completely figured it out. It looks like I'll have to get under the hood and loosen some bolts - maybe this can wait a bit. I pulled the speedometer out (easy btw) and cleaned it / turned it back to all 0s. (actually, I went a tad too far - it reads all 9s, but my first drive should take care of that.) To turn it back, I disassembled it, and used a RC car motor with gear to spin - it wasn't easy and it took me about two hours (why did I buy a car with a speedo reading 55000 is beyond me :P ).

I shipped off my splined adapter to CANEV, and I'm waiting on hearing from them to decide when to actually purchase the batteries. I've got plenty to do till then - I'm finishing up 2 master's courses in the next 2 weeks, and a Business trip after that. Hopefully I'll have good news after I get back from my trip. Any spare time between now and then will be used to pull the old engine and clean the other 2 seats (Windex and a plastic brush work great.)

One other thing I found is that the fuel gauge is resistive - YAY! That means I can use a uC to tell the gauge my current charge state.

I'm off to do research and write a couple papers.

[Ziggythewiz]

Originally Posted by otedawg

I pulled the speedometer out (easy btw) and cleaned it / turned it back to all 0s. (actually, I went a tad too far - it reads all 9s, but my first drive should take care of that.)

Too far, or not quite far enough? Doesn't it roll over at 100K?

How long did it take to get it out, and how involved is it? Mine's busted and I want to fix and set it, but don't want it to take me off the road.

Do some before and after pics of your seats. I'm curious to the condition and if mine might like to be cleaned.