Lithium Swap 9 - Into Town

After a couple of additional short trips around my local area, each a bit longer than the previous, it was time to take a trip into town the first week of July.

Drove slowly past the fire station and out to the intersection with the road into town. Looked both directions and turned left onto the road through the yield sign. Once I was fully on the road, I caught sight of a loaded log truck bearing down on me from behind.

Nothing to do but nail it and keep shifting. He never fully caught up with me, I was doing 50 pretty quickly. He wanted to go 45+, but I was more interested in keeping it slower, so after 3 miles, I pulled off the road at Condon Creek and let him pass.

The car was performing well, and I continued into town, noting the consumption on the E-Meter was a little higher due to the acceleration, but otherwise holding at the new, lower levels.

About 3 miles out of town, I caught up with the log truck, which was now creeping along at 2mph behind a county road painting truck that was striping the white fog line. I pulled off the road at the boat ramp just before I got to them, and spent 5 minutes checking the brakes for heat, feeling the motor, and checking the battery compartment.

When I got back on the road, I caught up with them just as the paint truck was pulling into the parking lot of the Mormon temple and the log truck was continuing up to highway 126.

Total consumption for the trip, 26 ampere-hours for 13.5 miles of travel. Went to the recycle yard and plugged into the 240 volt outlet that I installed for that purpose. Hung around looking into wrecks at the far part of the yard and watching Scott load a 40-foot semi-trailer with crushed cars and scrap metal, using a log loader. Amazing how flimsy even a big pickup truck is when a big pair of jaws gets a hold of it!

Charged the car fully, bought some groceries, drove home at a more leisurely rate, no cars following.

So far, so good. Next trip, I'll charge back 90% of the consumption at the yard, extending my range. I'll do this over and over until I either have a full round-trip's worth of consumption, or I get a "dead cell" alarm, at which point I'll know the capacity of the battery.

On subsequent trips into town, I charged the car less and less fully, pulling more energy out of the battery pack each time while noting the reading on the gauges.

I was still somewhat concerned about the condition of the brakes, so I decided that some research on brake systems was in order. I was reading a web site (www.stoptech.com) written by the brake engineer who had designed brake systems for all of the Caroll Shelby Mustang GT350 and 500 performance cars for street and track. His contention is that if you smell "brakes burning", then your system has been compromised, and you need to take repair action.

I took the calipers off all four corners of the car a couple of times, working on sticky pistons, etc, but never taken the rotors off. Now that I had about 400 miles on the conversion, I decided I'd better check out how the rusted rotors were polishing up.

The fronts weren't too bad there were some circular tracks and blobs of rust that weren't getting rubbed off by the pads. In fact, it looked like the pads were wearing to the tracks and blobs. The Stoptech site said that overheated brakes cause the binder (glue) in the pads to adhere to the rotors, and it bonds with the cast iron of the rotor to form a very hard, impervious layer that won't polish off like ordinary rust.

I scraped the front rotors with a razor blade, removing the tracks and blobs, then orbital machine sanded the rotors on both sides with 60 grit garnet sandpaper, per the Stoptech.com page advice. Also sanded the pads to break the glaze and rough them up.

This really wasn't planned in advance, but the irony of having Elon Musk
appear in a blog post about my EV is irresistible.

The rear rotors were another story altogether. Both rear rotors were absolutely black, they looked burned, although I didn't see the right rotor get very hot during my first drive. The razor blade wouldn't even touch the black layer. I ended up hand sanding both rotors with the 60 grit. It took over an hour per face on each rotor. Have I ever mentioned that I ~hate~ sanding? Sanded the pads with the orbital. The wheel bearing grease felt like summer butter. Cleaned it all up in solvent and repacked.

There's no reason to think that my range will change, unless there were still some draggy pads, but I think I learned my lesson on letting a car sit and then just drive it away, assuming that the rust will just get scoured off by the pads, it won't.

I still need to bleed the rear brakes, boiled fluid is likely on the left where the heat was the worst. Excessive heat causes gas bubbles to form in the caliper chamber, which makes the pedal spongy.