Sun Splash1 Click here for further information Finger W Lofrans X1

Electrical Equipment & Systems


AC Distribution

Windlass & Control

DC Distribution

Battery Management

The page provides information the primary electrical systems, mostly through links to the manufacturers handbook.  Systems related to specific areas may be found here Safety & Signalling,  Water, Galley and Engine.

image006 image704 image085 image641 regulateur_MB12_24

Primary charging is via a Bosch™ alternator, Mastervolt™ three stage regulator and zero-voltage-drop Mastervolt™ isolator between the starter battery as service battery bank.


The controller is the recent Masterbus™ model although no Masterbus™ system is present on ARAMIS.  With the correct adaptor, the bus could be connected to the NMEA bus such that charging information is available on the B&G™ Zeus2 MFD.



NB. the Bosch Alternator is not specific for low speed marine engine applications and will therefore never achieve its 70A maximum output.


Victron MPPT 70/15 solar charge controller



Mastervolt Battery Mate 1602 zero drop battery isolator

Installation Guide

Mastervolt AlphaPro MB alternator controller

User Manual

Alternator Guide (see page 11 re. Bosch alternator

Mastervolt BluePower IP22 12/15-3


Bosch 0 986 034 650 (3465) 70A alternator

Mounting Dimensions


Should there be a problem with the alternator controller or the brushes, the original non-intelligent regulator can easily be reinstated.

When on mains-power a 230V a.c. to 12V 30A multi channel three-stage charger is present.  This independently charges the starter battery and service bank.


The charger also has a "Recondition" function that provides a controlled overvoltage/current output for periodic desulphation (equalisation).  This function can be accessed from the panel on the charger.


The charger also acts as a power supply such that services can be run in port without discharging the batteries.


"Reconditioning" mode selection button behind electrical panel


A 100W mono-crystaline solar panel is connected via a socket below the pushpit rail to a 15A MPPT controller. Note that this significantly more efficient than the less intelligent PWM units.


The solar panel is the semi flexible type, however, due to reliability issues with a previous panel of this type, this one has been mounted in an aluminium frame.


The panel is stored under one of the setee bunk cushions when not required.


Taking into account the inefficiency of the panel (indeed all panels in real-world circumstances) and the negative temperature coefficient, we would expect a charging current of approximately 4.5A with good illumination and the batteries at 70% charge.

100W semi-flexible solar panel

Service Batteries

2x Victron 130Ah deep cycle gel batteries are present under the cockpit floor and accessible from the cockpit lockers.


The batteries were new in 2015.

Gel 12-130 Gel 12-130

Victron 130Ah gel deep cycle batteries

Data Sheet

image722 5906_masterlinkbtmiii

The starter and service banks are isolated with a BlueSea Systems battery switch panel. The switch allows both banks to be combined for emergency starting.


The panel also contains the primary 100A magnetic cutout to the dc distribution panel and three 24h circuits that are connected to the primary and secondary bilge pumps and the gas and holding tank alarms.


All three battery banks (starter, service and VHF back-up) are monitored by a MasterVolt BTM III monitor.


A shunt provides accurate, real-time monitoring of the service battery bank.



The emergency VHF battery is switched by a dedicated control unit that also features an automatic mode.


Note that although this unit is homologated in Spain, the design is rather poor.  The unit will often switch when there are transients on the 12V services circuits, for example when a pump is switched on.  Moreover, the blocking diode in the unit that prevents the emergency battery from discharging in to a flat service battery bank drops >600mV.  This means that where intelligent charging systems are used (as is the case with ARAMIS) the supply voltage is rarely high enough to charge the emergency battery.


To overcome this, we have installed a diode by-pass switch for when charging is required.

BTM III battery monitor and shunt

Installation Guide


image686 image001 image060 8686 Battery panel image279

BlueSea Systems 8690 battery panel

Instruction leaflet

VHF Ghost Ac panel

Shore power comes in through a splash proof junction box containing a 10mA differential cutout and 2x30A circuit breakers (one unused).


This feeds a BlueSea Systems ac distribution panel that has a meter showing voltage, current, power or ac frequency. It also has a refers polarity indication (i.e. relative to the shore earth connection)



The panel has 3 outputs :


- battery charger

- cabin ac socket

- spare

The ac panel can also be fed from a MasterVolt 500W pure sine invertor.  This is done by connecting the invertor output into the shorepower socket that is in the starboard cockpit locker.


10mA differential cutout and 2x 30A breakers

BlueSeas XXX ac panel


MasterVolt ac Master 12/500 Invertor


The output of the invertor simply connects in place of the shorepower cable when required.


12V DC is distributed via a BlueSea Systems panel with 13 separate 15A magnetic trips routed as follows:


1.    Fresh water and salt water pressure pumps

2.    Navigation lights (also powers compass illumination)

3.    Mast head strobe

4.    Anchor light

5.    VHF and power to the DSC GPS antenna, AIS and the VHF emergency battery controller

6.    Engine Blower and extractor

7.    Steaming light and illumination on engine instruments

8.    Accessories (12V socket, 5V USB charging adaptor and handheld VHF charging station)

9.    Cabin lights and cabin ventilators

10.  Refrigerator

11.  Autohelm computer

12.  Instruments (also powers spare auto pilot socket)

13.  Bilge pump (manual)


The panel has a meter that can show the voltage on all three battery banks and, via a shunt, the total current or power consumption of all dc loads routed through the panel.



BlueSeas XXX dc panel


image722 image401 image303 image113 image380

The windlass (new 2015) is a Lofrans X1 rated at 500W with a 6mm gypsy.


It has a dedicated 12V connection from the battery panel battery selection switch via a 50A thermal cutout.


The high current switching is managed by a relay mounted close to the motor in the forepeak.  The relay is actuated via foot switches on the foredeck or from a toggle switch in the cockpit.

BlueSea Systems 7039 50A cutout


Lofrans X1 Windlass and relay

Installation& Maintenence

Foot and toggle switches