battery/charging/cranking problems

[LMP]

On this forum and others, several have complained of battery/charging/cranking problems. It was often suggested by myself and other forum participants to check for corrosion on cables and connection at battery. While long time experience shows this is a pervasive problem, a very recent experience proved me it was even more than I would have expected.
With a 5-6 year old battery, I was not surprised I would have starting problems so while the car was left in the garage for the winter time, I did not care much. When I tried to start it recently, I found a "like dead" battery. Charged it , but it would barely crank, or not at all.
Convinced it was finally the time to buy a new battery, I removed all that is required to reach the battery , windshield washer tank, fender brace - then removed battery. I tried another used battery I had – to no avail ???!!!...skip a few details...but finally I discovered (before going for a new battery) that the side connector – the cable end that connects to the battery positive pole – was covered with a whitish substance. Digging into that, it proved that the washer like lead cushion ( that is part of the cable connector and assists in making better contact with the battery) had totally corroded and had turned into a hard pressed lead oxide powder coat about 1/8 inch thick that was everything except an electrical conductor. It was VERY hard to dislodge ; I finally got back to neat copper, and temporarily reconnected it to the battery just like that.....and suddenly I had all the power I needed for starting . Then installed a new lead cushion.
This is very insidious because contrary to top battery connector where we can have some visual cues about corrosion, this one was totally invisible to the naked eye and even a quick glance at the connector – notice it is not in a place for an easy eye capture, even with battery removed – would not reveal something obvious.
So, I got my lesson again: if it does not crank and all lights go dead, DOUBLE CHECK BATTERY CONNECTORS.