GU Patrol

Unfortunately the weakness of the Optima's and similar valve regulated batteries is they dont like heat whilst charging. Although they cycle well etc - if they are exposed to heat whilst charging they are more suseptable to damaged - overcharging - and will then only last as long as a good wet or gel battery. As with any battery keep em cool especially if you want them to last.

Heat is generally a killer of all lead-acids. With this in mind, and a turbo in the vicinity, I fitted a shroud around the battery, and for good measure, a 100mm 12v computer fan (avail Jaycar or Altronics) to suck fresh air in from the grille and blow down the gap between the shroud and the battery. Controlled by a thermostat switch, mounted on the shroud nearest to the turbo, to cut in at about 50degC (avail from Radio Spares). The fan could be just run off the ign switch, and it draws only about 150mA. Works well, got over 2 years out of a cruddy ED5, then it only died coz someone stuffed it forme.
Gerry