Battery Charger
A device that converts alternating current to direct current in order to charge a battery. A charger must be matched to the battery it is charging in voltage (V) and capacity (Ah).

Rapid Charger
Also called Fast-Charger. It usually charges the battery in about one hour. Since it uses a high current to charge the battery, it monitors the battery during charge . When the battery is fully charged it switches to Trickle charge to compensate for the self discharge of the battery. The battery can stay on the charger until it is needed.

Standard Charger
Also called Slow-Charger. It usually charges the battery overnight (typically 12 to 16 hours). It does not monitor the battery during charge because it applies a small current to the battery. When battery is fully charged, it should not stay on the charger more than few days.

Charging rate
The charging current expressed in amperes (A).

Discharge rate
The rate in amperes at which a cell or battery is discharged.