The PSC-124000ACX is part of our ACX series of sealed lead acid (VRLA) switch-mode battery chargers. The ACX series chargers are switching type chargers which operate without the use of transformers. I.C's control and regulate current and voltage and automatically switch from higher fast charger voltage to the lower float voltage when batteries are very close to be fully charged. The 12V 4000mAh battery charger is ideal of cyclic applications where recharge time is critical and timely charge termination cannot be relied on.