[wilkin250r]

No, most "smart" chargers will not bring back a completely dead battery. They constantly monitor the battery voltage so they know when to switch from bulk charge, to trickle charge, to float/maintain (or even desulfation modes).

Because of all that fancy gadgetry and witchcraft, they won't charge a battery that's at zero volts. They need to sense at least 10V (which is a dead battery, as Blessed pointed out a few posts ago). Anything below that, the charger will not kick on the "charging" circuits.

The old dumb chargers will still work, but then you have to monitor the voltage and time, as they have the potential to over-charge and damage the battery.