Project Civic Racecar Waits for Tech Inspection

Project EF Civic Racecar: Witchcraft & Wizardry

We already documented that on our first shakedown, we found a massive oil leak.  Our second shakedown went better as we were at least able to complete two whole days of autocrossing.  However, we still had a problem: while rolling back to the grid after my first lap, I noticed the kill switch was smoking.  There was no obvious issue: the car was running fine, and the electrical system seemed to be working.  I re-tightened the nuts on the terminal lugs and competed for the rest of the weekend with no issues.  I decided to order a replacement kill switch just in case.  It was only a couple weeks later, when we needed to move the Civic, that we discovered there might be a bigger problem with the car.  It’s time to break out our magic wand and dig into everyone’s favorite topic: electricity and wiring.

Probing the Civic's old battery with a multimeter. It reads 4.88V instead of the usual 12-14V
When we turned on the power, nothing happened. The battery was totally dead and refused to charge. That was when we noticed the leaking battery acid. The battery had failed.
Comparing the size of the original battery with the much smaller Braille AGM battery and their mounting brackets.
This gave us the perfect excuse to ditch the factory lead acid battery for a compact and light Braille battery. The battery we chose is an AGM battery that weighs a mere 6 lbs. This battery is affordable, compact, and lightweight while carrying 210 CCAs of starting power. We chose an AGM battery, as Lithium batteries can lose some of their capacity when exposed to the winter cold. AGMs can be stored outdoors year-round. We also didn’t feel the extra $100 and hassle was worth the 1 lb weight savings over an AGM. The battery came with a new tie-down bracket and terminal adapters that make this a much easier swap than in our Cappuccino.
Braille AGM battery installed in the Civic.
The Braille battery is tiny compared to the stock lead acid battery. Best of all, we are located only a few miles from Tire Rack’s warehouse, and they keep these batteries in stock, so we were able to pick it up the same day we ordered it. The Braille battery only took a few minutes to swap in. The stock battery tray already had a hole that was in the perfect location for the rear J-hook. Ideally, we would move the battery into the passenger compartment for better weight distribution, but SCCA Improved Touring rules force us to keep it in the factory location.
The engine bay of the Civic with the new battery. Hood is open and showing lots of patchy rust where the battery mounts indicating a battery has exploded
With the battery in place, the Civic fired right to life. We decided to check the charge and found the alternator was running at 16V, which explains the smoking kill switch and the blown battery. The voltage regulator in the alternator went bad, overcharged the battery, and overloaded the kill switch. Judging by the suspicious amount of rust on the hood directly over the battery, it seems this is not the first battery that has failed in the Civic.
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