Anybody know more about Priority Start or have one?

http://batterymart.com/prioritystart.asp

Might be simpler solution than a second battery
for *light* accessory use when used with Optima.
They claim aux power doesn't disconnect battery.

From their FAQ:

PriorityStart! is a computer-controlled electromechanical system (handles
1000 cranking amps) that constantly monitors the vehicle's electrical
systems and battery power level. If, when the vehicle ignition is turned
off, it detects a drop in battery voltage to a factory-set level, (slightly
below 12 volts) then it automatically disconnects the battery, leaving
starting power in the battery. PriorityStart! ! automatically reconnects the
battery (any load greater than 100 microvolts) when the ignition key is
turned on. No buttons or switches to operate. No need for a battery booster
unit. PriorityStart! ! is totally automatic!
What if I want to leave the hazard lights on with the ignition switch turned
off? Even though the engine is not running, if other electrical sources are
operating on the vehicle, such as hazard lights, flashing emergency lights,
strobes, auxiliary power supplies, PriorityStart! reads this as engine NOISE
and will not disconnect the battery.

Paul Mayfield
'87 vestee