1967-1969 Delco Energizer R-59 Maintenance-Free Battery

[Kurt S]

I did alternators and batteries for an OEM for many years.
Top two killers of batteries are high temps (why some batteries have insulation around them) and deep cycling.
If a high frequency pulse is applied, it will remove sulfate build up which is covering the plates. PulseTech manufactures this technology (there may be others). I've used it to recover batteries that couldn't even crank a car - and then used the batteries for several years.
A quick look at their current product line found: http://www.pulsetech.net/XC100P-Xtre...ator-7346.aspx

Many trickle chargers overcharge the battery, fwiw.