Keeping in mind Paul's 144V Open Source Controller Project, I wanted to see what it would take to up my Metro to 144 volts.
Currently, I am running 6 batteries for a 72 volt system.
My batteries weigh 70 lbs each.
That means the batteries I am using right now weigh 420 lbs. 6 more batteries would be an additional 420 for a total of 840 lbs of lead.
The GVW marked on the door frame says 2590 lbs.
When I weighed the car with the ICE in it at the landscaping scale, it clocked in at 1780 lbs.
I think the conversion to electric (with the exception of the batteries) comes to about the same weight as the original. The motor I put in actually weighed less than the engine I pulled out. I also pulled off the gas tank, radiator and other bits, but then I added in a battery charger and some front steel reinforcement for the "radiator-position" batteries.
So, I am guessing the car frame weighs pretty much the same with the ICE or the EV system.
If it does, that means I have 2590 lbs - 1780 lbs (weight of car) for driver, passenger, and batteries.
810 lbs to work with comes pretty close to twelve of these lead-acid batteries, however, that's WITHOUT a driver or passenger.
I weigh about 190 lbs in winter clothing. That puts me plus 12 batteries OVER the gross vehicle weight.
Hmmm...
Well, I am still in the mood for experimenting, so lets load up some batteries.
I put the "second-string" of batteries in the back of the car. I could fit only 3 on the floor (trying to bring the weight forward) but the other 3 had to go on the back seat.
(Note that while the batteries look a bit strewn about, they were all nicely strapped down before driving. Once upon a time I had a bad experience with a loose flooded battery, and now I know better!
)
I measured the height from the ground to the center directly above the rear wheel, both before AND after loading the batteries.
On the back, I lost 1&1/8 inches. Pushing on the bumper showed that there was minimal suspension left. It did go up an down, but not much at all.
I took a ride down the street, and found that acceleration was a bit more sluggish, and did pull more than the usual amps to get going.
Braking distance increased slightly, but was still no problem. I tested the brakes with the vacuum assist deactivated and found that it was no problem stopping the car without power as well.
I wanted to make a video of the extra-heavy ride, but the cold was effecting my tiny camcorder battery as well, and it kept dying on me.
If I want to upgrade to 144V with these batteries, I will NEED to improve the rear suspension. I might also be able to fit another battery under the hood, two if I rearrange some things up there. Shifting battery weight to the front would help some. I can see why many scratch-built EVs use a "tunnel" of batteries straight down the middle.
It may make more sense to go with 120 volts. That would save me 140 lbs and the space needed for two batteries.
If I did upgrade to 120 or 144V, I would love to cut out the underside of the back seat and install a battery box below it. The center of gravity on the car feels great as it is, and a low battery box would REALLY make it stick to the ground.
The brakes seemed fine. I don't think I would need to do anything with them, accept maybe replace brake pads more often.
Since I finally got the registration sticker in the mail a couple days ago, I figured it was time to put that on the rear plate.
There were so many old registration stickers on there that I had to scrape all the old ones off with a chisel.
I had grabbed a wet paper towel to clean the license plate for a dirt-free spot to put the sticker.
When I opened the garage door, I had the wet paper towel in my left hand and opened the latch with my right and lifted the door. As I did this, the paper towel touched the door, flash-froze to it, and was ripped out of my hand as the door opened.
[Paper towel frozen to the door. It may be sunny, but it's -1℉]
I'm really starting to get sick of this cold. If only I had a passive solar garage....
When I put the registration sticker on the license plate, it broke in half from the cold. I just lined up both halves as best I could and stuck it on there.
That's it though, the one last thing I ever had to do to make the car a 100% official government stamp of approval A-OK road-worthy vehicle.
That's one more EV on the road.
