0.0V drop alternator splitting system built to IP65

12V/24V. 120A-250A.

Up to 2 alternator inputs and 4 outputs.

The Pro Split R is a 0.0V drop alternator splitting system. It is the successor to the old diode based splitting systems which induced large voltage drops at high current. The newer, much more intelligent, Pro Split R selects a battery banks and isolates the other battery banks to prevent their voltage misleading the alternator’s regulator (assuming regulator is connected). This allows the regulator to focus on the correct battery and can maximise the alternator’s potential. Then, at a specific level, the other battery banks are charged and finally all charged together. The charging performance can be further enhanced with the use of an Advanced Alternator Regulator.


Isolates the battery bank(s): The unit isolates when there is any attempt to back feed the power from the full battery bank to a more demanding battery.

Comprehensive L.E.D. display: that shows which channels are in use and which are not.

Micro Processor Controlled: All batteries are charged in conjunction with each other and back feed under high load conditions is prevented. The system also has the ability to disconnect the alternator and individual battery bank outputs in the case of problems caused by the alternator to other devices.

Alternator Regulators: The sense stud on the Pro Split R allows seamless integration of Sterling’s alternator regulator with this 0.0V splitter resulting in the ultimate split charging device.

Overload Design: The model rated for 180A is actually continually rated for 240A with overload in excess of 2000A.

High Safety Elements Built In: As much safety and control is built in as possible to protect your electrical system and to ensure available power is directed to where it is required most.

Fail-Safe: In the event of unit failure, the engine start battery and alternator remain connected. This ensures the safe running of the boat/vehicle. It prioritizes the engine start battery charging over all other battery bank outputs.

Isolates the main alternator: If the alternator was to fail, the Pro Split R would isolate all batteries to protect them from over charging (boiling).

Faster Battery Charging: 0.0V drop allows for a much faster charge. Additionally, once the Pro Split R is happy with the charge state of the starter battery the focus of the charge is directed to the larger domestic/house bank. This ensures a one on one charging experience between the alternator and house. N.B. The starter battery is always monitored and then prioritised if needs be.

Distributes the most power: to the battery bank which demands it.

Backfeed protected: If there is a defective battery charger on one battery bank trying to back feed into another battery bank, the unit would disconnect that battery bank to save others.

0.01 voltage drop through the current range: This negligible voltage drop is far superior in performance in comparison to the old diodes based splitting systems which suffered from a far greater voltage drop.

Larger Models:

The image to the right is of the largest Pro Split R in the range. It handles 2 alternators in and 4 outputs. The outputs include 2 x starter batteries (one on each side) and 2 auxiliary banks. The alternator maximum is 130A at 12V for this model.

Works with 2 x alternator regulators: Provides a 4 stage charging profile to each of the 4 outputs for super fast charging on all banks.

Not suitable for any modern European vehicle or any vehicle equipped with an advanced ECU. For suitable products look to the range of Regenerative Braking Friendly, such as the Battery to Battery Charger.

Pro Split R 0.0 volt drop intelligent splitter

DC (V) Max Alt size (A) Battery banks Size L x W x D mm Weight kg Code
12 120 2 150 x 80 x 120 0.6 PSR122
12 180 2 150 x 80 x 140 0.7 PSR182
12 250 2 150 x 80 x 155 0.9 PSR252
12 120 3 150 x 80 x 130 0.9 PSR123
12 180 3 150 x 80 x 150 1.0 PSR183
12 250 3 150 x 80 x 180 1.3 PSR253
Twin 12 2 x 130 4 150 x 80 x 295 1.8 PSRT134
24 60 2 150 x 80 x 120 1.8 PSR62
24 100 2 150 x 80 x 140 0.6 PSR102
24 150 2 150 x 80 x 165 0.7 PSR152
24 240 2 150 x 80 x 250 1.2 PSR242
24 60 3 150 x 80 x 150 0.7 PSR63
24 100 3 150 x 80 x 175 1.0 PSR103
24 150 3 150 x 80 x 220 1.3 PSR153
Twin 24 2 x 80 4 150 x 80 x 295 1.8 PSRT84
Power Variant

120A 2 battery banks PSR122, 180A 2 battery banks PSR182, 250A 2 Battery Banks PSR252, 120A 3 battery banks PSR123, 180A 3 battery banks PSR183, 250A 3 battery banks PSR253, 2 X 130A 4 battery banks PSRT134, 60A 2 battery banks PSR62, 100A 2 battery banks PSR102, 150A 2 battery banks PSR152, 240A 2 battery banks PSR242, 60A 3 battery banks PSR63, 100A 3 battery banks PSR103, 150A 3 battery banks PSR153, 2 X 80A 4 battery banks PSRT84

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