@ 4pyros: I am not sure a desulfator can desulfate the source from which it is powered. Can you point to a design that does that?
I powered it up with a 12V supply. Pin 3 of the NE555 puts out a square wave at 10.16 KHz with a duty cycle of 86%. Those might be the "magic" numbers for those who believe in desulfators. With a 50 Ω resistor in the supply line, you can see the expected glitches as the 555 switches. With no resistor and even with a relatively low current supply (Agilent E3630A), the power line was absolutely steady.
There is an LED that flashes. Maybe this is an expensive LED flasher to remind the operator he still has a battery.
Unfortunately, it is in the battery compartment that is not easily seen from the operator's station.
Edit: Total current draw is about 20 mA (i.e., about 0.5 Ah per day).
John