Advanced Digital Alternator Regulator Pro reg D + DW (PDAR/PDARW) Remote Control only

Pro Reg D advanced alternator regulator (includes two temperature sensors).

Unit actual rating (the actual device rating) for the Pro Reg D

By far the most powerful regulator around due to its fan cooling.  Positive field control 25A max field current.  Negative field control 30A max field.

Real world rating (rule of thumb):

12/24V alternator with standard regulator fitted.  Up to approx 600A alternator, more if a negative field control. 400A if stand alone, without existing regulator fitted.

Please note advanced regulators are not suitable for some modern vehicles / boats with integrated engine management systems as they increase the alternator’s voltage and this can be interpreted by the management system as a fault on the alternator. Please use an Alternator to Battery Charger or a Battery to Battery charger for these applications.

The Pro Reg D features explained.

The Problem with standard systems: Standard alternators are not designed to be good battery chargers; they are designed only to charge an engine start battery sufficiently to start the engine. Due to this inherent weakness, a more advanced regulator is required that, in effect, converts an alternator from a constant voltage battery charger to the latest 4-step progressive constant current battery charger (see battery charger graphs). Because of this improvement in the alternator’s control system, these regulators dramatically enhance the alternator's charge rates by between 200-2000% depending on how poor the original system is.
The Sterling Regulator is designed to charge batteries as fast as possible and to their maximum capacity without damage to the batteries or alternators.

What To Expect From An Advanced Regulator:
1) Maintains maximum performance of an alternator’s power curve within a preset envelope as defined by battery manufacturers.
2) Batteries charging 4-20 times faster. ( depending on original system ).
3) Enables 25-35% extra useful power to be stored in batteries. A conventional alternator will only charge the battery to a max of about 75% and, at about 35% remaining capacity, the low voltage level renders it useless. This means that, of 100A of battery capacity, only about 35A are available to be used. An advanced regulator will fully charge the battery giving an extra 25% capacity. This increases the useable available power by about 70 - 80 %.
4) Battery plates kept free from sulphate damage results in longer life.
5) Due to the built in safety features, in the event of incorrect installation the unit will switch itself off.
6) Reduces needless running hours on the main engine.
7) Compensates for voltage drops resulting from long cable runs, ammeters, diodes and other general wiring associated problems.
8) Automatically converts a machine-sensed alternator to a permanent battery sensed alternator.

SAFETY FIRST: The Sterling Advanced Regulator is full of safety features to prevent damage to your system. In the event of incorrect installation or a fault developing on the boat or vehicle, the high voltage trip picks up high voltages at the batteries and the alternator and switches off the advanced regulator (the field circuit is disconnected totally from the control via an internal relay).

The Test: Using a standard 12V, 90A Bosch alternator fitted to our test bench and rotated at a constant speed, the following test was undertaken: 4 x 100A ''leisure'' batteries were used, they were split into 2 battery banks, one for engine start and three for domestic. The engine start battery was fully charged (to copy that in real life) and the 3 x domestic batteries were discharged until such time as one of our 1800W inverters tripped out on low voltage. To make the test fair we linked 9 batteries together to make one large battery bank then discharged them all to exactly the same level, then, at random, three batteries were selected and used for each test. The idea was to see how many amps could be replaced into a 300A battery bank. Bank discharged to a level one would expect in real life (i.e. about 50-60% empty) over a 3 hour period and to display the results in as simple a way as possible to highlight the difference between all the different options and why an Advanced Regulator is a necessity, not a gimmick.