Hi, was checking my '95 Civic 1.6L today. It was idling, and I heard the idle sound change: it seemed higher. I stepped on the gas a bit, and I heard a soft electrical "pop" near the stereo panel. I hurriedly shut down the engine, I found that the negative battery cable had come off! (It had a quick-release connection). I connected it, restarted and found everything working fine, even checked all the stereo functions, LEDs, and the ECU.
I've read that the battery acts as a big capacitor to smooth out voltage spikes. The entire episode didn't take more that 10 seconds, but I'm worried... could there be any permanent damage?