The charger charges quickly and easily on all lead-acid batteries. The
charger delivers full current, decreases until the current from the
battery to 150 mA. At this time, a lower voltage to complement and
support more load. If the battery is fully charged, the circuit stops
and lights a LED indicates that the cycle is complete. This very simple
circuit uses a transformer, two diodes, a capacitor and an ammeter. To
charge a battery just connect the and – terminals of the circuit at
the terminals of the battery. If the battery is not charged, shows the
ammeter reading 3.1 amps. If the battery is fully charged the ammeter
reads zero or nearly zero.
If the circuit is powered off, the battery should be disconnected from
it's output otherwise the circuit will drain the battery slowly.
T1 is a transformer with a primary voltage appropriate to your location (120V, 220V, etc.) and a secondary around 2 X 12V 5A.
