In my continuing quest for range, I have now maxed-out my batteries and GVW!
I already removed the back seat and have been comtemplating the best way to cut a hole in the floor where the backseat and gas tank below it were.
I figured I would check to see what would actually work first.
Since I knew pretty much where I wanted the batteries to go, I rigged up a temporary way to mount them to try it all out.
On the back seat, I used a couple of self-tapping sheet metal screws to zing in a piece of scrap angle iron to make a lip to rest a small chunk of plywood on. The front edge of the plywood sits on "the hump" in the middle of the old seat space. I made two little spacer wood blocks to support the front two corners.
I set four additional batteries on the plywood platform. I am starting to get smarter now. Instead of all batteries facing the same way, I finally figured to have each rotated 180 degrees from the last. That way, it leaves the middle of the battery open for a tie-down cross member.
To connect these four batteries in parallel to the four already in the way-back, I connected the positive from from string B to the positive in String B, and the negatives of both strings to each other as well.
It feels very strange to be connecting matching polarities like that, but nothing sparked or exploded!
I then still needed two more batteries to run in parallel with the two front batteries. I have to take the entire front end of the car apart to get to the radiator batteries. My master plan is to rotate them 90 degrees so I can fit two more up there.
Well, for now, I already had the two "turbo" batteries on the floor of the passenger seat. They already had cables running through the firewall to the reversing turbo contactors.
I disconnected the cables from the contactors and instead attached them, positive to positive, and negative to negative, to the front two batteries.
I think plugged in the Anderson disconnect. No sparks! No car leaping forward!
Looks good so far!
I turned the car on, and it started as normal. Click. (Key) Ka-lunk! (main contactor) Whirrrr! (Power brakes vacuum pump)
I went for a short spin around the neighborhood. The suspension didn't seem too bad, considering how weighted down it was.
My ammeter shunt is connected between batteries 5 and 6 of the original string (in the front of the car - radiator batteries.)
Since the other string of batteries is providing half the power to the controller/motor, the shunt should now read how much power is coming through battery string A, only half the total amount.
Sure enough, the ammeter reading seemed to be about half what it usually was. However, when I accelerated hard in higher gears, I was still able to get the ammeter to shoot up to 300 amps!
How is this possible? I only have a 400 amp controller! Either my shunt and ammeter are faulty (not calibrated to each other?) or for some reason, the motor is pulling more amps from string A than string B!
Any thoughts on this?
Also, I did notice that battery voltage sag was not as bad. I could gun the accelerator and the total pack voltage did not drop as much as it would have before with only the single string of batteries. I think this is an overall advantage as I now have the upper hand against Mr. Peukert and his effect on my lead-acid batteries.
I will try another test run tomorrow in the daylight and see what kind of range I can get.
In theory, it should be double what I had! (Hopefully, the gain against the Peukert effect will off-set the additional rolling resistance gained from the extra battery weight!)
The extra range should make the vehicle MUCH more useful! I am hoping it will be enough to make the vehicle practical as primary transportation while I convert my truck to bio-diesel.
[Edit]
Here are some photos of the parallel battery pack.
