I "don't do car engines" anymore, I don't know what all that stuff is under the hood which appeared in the last 30 years. The other day Wifey's '04 Explorer battery wouldn't spin the engine, had juice just not enough. Last time when the old battery went totally dead it did some sort of computer reset and had to be "seen by a professional" to get it going again... I charged it a bit and it started.
All it needs is cleaning the battery terminals properly and then grease them. BUT, what happens when I disconnect the cables for the cleaning? These are the cheapo Ford springy/no bolt type. I really don't want another service call to the house for a reset.