patching a hole where the rain gets in

The carpet on the driver's side is always wet when it rains. I pulled it back to see why.

It's a bit perforated. I found a sheet of metal in my scrap and cut a patch for it.

5 year aniversary

This post marks my 5 year anniversary! 25,000 miles total. No battery issues! I estimate I have saved $3250 worth of gas at $2.60 per gallon, have paid $832 in electricity at $0.10 per kWh, and have 458 cycles on my battery.

Refresh EV grin

Step 38: refresh EV grin. Closing out my 5th year of driving I decided to upgrade my motor controller to a Zilla. At 1000A this will double my HP (but not affect my top speed).

The Zilla is a high-side switch so I had to run a new power cable from the controller in the trunk up to the motor. While I was under there I inspected my brushes. They look brand new.

I spray painted the power cable orange like the others. The Zilla is liquid cooled. I'm using a PVC pipe for a reservoir, a 12V pump, and a radiator for a power steering cooler located under the trunk.

I also added a little wall to mount the reservoir and to protect my rig from groceries.

window crank

This window crank broke in half.  I fixed it several times but in the end could not get epoxy to stick to the metal.  I gave up and got one off ebay.

more flex disc'n

The last flex disc lasted only 9 months.  The 3 that have been eaten were M/T brand.  I put a Meyle brand on this time. 

New driver training

Front brakes

Old car stuff.  I knew the front brake calipers were from a ‘75-‘83 BMW 320i, and the brake lines were for a 2002tii booster, but I didn’t know the hubs were from a BMW 2002 standard. I replaced the rotors, one of them had warped.

Brake job

I was driving my friend home when the brake pedal went to the floor.  Where did the brake fluid go?  A failed slave cylinder.

Instrumentation

For four and a half years I've been operating without any battery instrumentation.  Professionally I work in the field of battery charge estimation, algorithms that decide whether to light 1 LED or 5 LEDs.  My cousin recently gave me a ride in his Tesla Model S and pointed out the irony to my lack of battery charge gauging.  I simply make sure I don't drive more than 40~50 miles on a charge.

When in a pinch I have read the voltage of a single cell with a voltmeter to get an idea, when fully relaxed these voltages are directly related to state of charge.

I've run out of charge only 2 times so far.  One time because I forgot to charge the night before.  And the other time is still a bit of a mystery.  I thought it was perhaps due to running the air conditioning over lunch break but that would not account for how much charge I lacked to get home.  Both times I simply called AAA and was done.

There is a communication port on my battery management system and I've used it for diagnosis using a laptop and to log data using an iPhone.  The iPhone was really too small to be practical and was abandoned.  My family recently upgraded from an old iPad to a Kindle Fire and I've adopted the iPad with cracked screen to up my game.

As a security feature it hides nicely under the passenger seat.  With this I can monitor and log voltages, temperatures, and current.  The app I'm using is called Get Console and is basically a HyperTerminal for iPhones.  I hope to do some more data collection and efficiency calcs soon!