nile13

Alex, that's pretty much my thought on batteries as well. Just thought that AGM technology could buy some advantage I'm not thinking of off the top of my head. Apparently, no magic bullet.

I charged my Exide on a home charger and threw it back in the car. Will see how it behaves. Something tells me it might just be OK for a while.

IXLR8

They have two that I can think of, other than taking a deep discharge better, but then that should never happen. They have lower internal resistance and a lower rate of self discharge. Neither of those are important to the vast majority of us. I can see using one in extreme cold conditions.

If you have a Harbor Freight nearby, pick up one of those 500A carbon pile load testers when they are on sale.

Also a rapid discharge showing up as a voltage that is decreasing fast (provided you do not have a current drain other than the typical amount) tells me your capacity is down.