Good article on batteries

Seems like a good overview.

They did skip over the 'sealed' battery development, with GM's 'green eye' indicator. I was a doubter, but when I a bought a car that had one, I was very impressed how long it lasted even though I didn't have to maintain it.

Also, I don't know what they mean by AGM's can be charged faster. Maybe when lightly discharged that's true. They certainly can NOT be charged at a higher rate than wet cells over any long period of time. When AGMs are low they need to be charged with a controller, or at moderate to low current on fixed rate charger. Some of the manufacturers say up to 10 amps is OK. My suggestions is set it to 2 amps or less unless you are monitoring it every 10 to 15 minutes. At higher currents, the heat gets retained and will cook the battery. You can just touch the case and feel it. There's nothing subtle about it. Its really not that different than when charging a low wet cell battery but less able to dump the heat. JMHO.