BOSCH marine alternators are delivered ready to be fitted with any external regulator.
Kuranda uses the mastervolt Alpha - PRO Regulator as standard with all models, that ensures fast, safe and effective charging. The charge voltage can easily be adjusted to compensate for any possible voltage losses.
The Alpha Pro 3-stage charge regulator is fitted with temperature compensation to ensure the alternators' charge voltage is optimised under all working condition.
With these features, the combination of high output alternator and true 3-stage charge regulator controls and manages the charge voltage in exactly the same way as a modern mains powered automatic battery charger.

Three Stage Charging

Three stage charging has two advantages. Firstly, it allows deep-cycle (semitraction and gel) lead-acid batteries to be charged as quickly and as effectively as possible. Secondly, it ensures long battery life by maintaining a safe float voltage after they are charged. The charge cycle (that is controlled and managed by the Alpha-PRO regulator) begins by supplying the maximum available output current of the
alternator. When the batteries reach the  voltage setpoint(14.25/28.5 Volts), the absorption cycle begins. The batteries are held at this voltage, where they gradually absorb less current as they become more charged. After the batteries have been held at this voltage for several hours, they are normally fully charged and the float cycle begins. During the float cycle, the batteries are mainained at a lower voltage (13.4/26.8 Volts) where there is no water consumption or overcharging. Full output current of the alternator is
available for the DC consumers in the system.

Why a marine alternator is recommended

All inboard propulsion engines are fitted with an alternator as standard. The charge current is restricted to maintain a trickle charge for the starter battery and is not powerful enough to charge a service battery. The BOSCH Marine alternator is designed to give a real charge to the service, radio or bow-thruster batteries, regardless of the technology of the battery (gel, wet or traction). Multiple bank charging can be done without problems as the external regulator allows you to adjust all voltage settings that are required. Now the batteries can be charged quickly and completely even at low engine speed.