Electrical Diagrams – Mastervolt Charger/Inverter, Solar Panels, Balmar 100A Alternator/Regulator

Relay to starter solenoid was added after the wiring got so old that the key switch was not providing enough current to reliably engage the solenoid. Easy fix, very reliable.

The electrical system on Sea Dream has been heavily modified to meet increased energy demands.

• Three methods to charge the batteries:
  • Alternator was upgraded to a Balmar dual-output 100A alternator with a Balmar MC-612 regulator. This charges the House bank ONLY. (Do not get a dual output alternator- there is no easy way to use both outputs).
  • Balmar Duo-Charge automatically charges the starting battery any time it senses that the House bank is being charged (by the engine, solar panels or shore charger). (programmable for any battery type).
  • (4) 65watt Solar Panels (PowerUp) above the bimini provide enough power to keep the batteries charged at 100% while away from the dock. Blue Sky Systems MPPT Solar Charge Controller is used. This provides between 80-100 amp-hrs/day back to the batteries. Note this charge controller and the Balmar regulator fight with each other (each tries to charge and then backs off over and over). Net result that no charging takes place. I installed an oil pressure switch on the Yanmar so anytime the engine is running the Solar charge controller output is disconnected automatically. When you shut the engine down, the Solar panels reconnect and continue to charge.
  • Mastervolt Charger/Inverter charges the House batteries at the dock, and the Inverter provides 2500 watts (Surges to 5000 watts) of 120vAC power when sailing. It also will auto switch at the dock when on shore power to help provide additional power to devices on board if dock power is insufficient.
• House bank consists of (4) 6v LifeLine AGM Batteries (Model GPL-4C, 220 amp-hrs each) which nets 440 amp-hrs total at 12v. (Two batteries in series, then two pairs in parallel to get 12v/440 Ahrs).
• Engine start battery is located under the galley sink (LifeLife) Group 27
• Battery Monitor is an old Xantrex unit that monitors two battery banks using a shunt. I would replace this with a Victron BMV-712 Smart monitor with bluetooth built in.
• Additional Notes:
  • I removed the original Battery 1-2-Combine switch. I only have an On-Off switch for the House, one for the Engine, and one that combines the House and Engine batteries in case the Engine start battery is dead.
  • Be wary of the Balmar regulator and Solar charge controller– they may fight each other to charge the batteries. You may need to disconnect the Solar charge controller when you charge the batteries with the engine running.
  • Intermittent starting issue & Fix. A few years back the engine no long would reliably start. The voltages seen at the starter solenoid were acceptable- but it turned out not high enough for reliable starts especially when warm. Easy fix was to install an automotive relay next to the starter solenoid so turning the key now just energizes the relay. I pulled 12v off the one side of the starter solenoid (that goes to the starting battery) to the relay, and the output of the relay goes to the starter solenoid coil. Since the engine always stars reliably. (See the diagram for details above).

Updated Electrical Panel(s), Xantrex battery monitor, MasterVolt Inverter Control, Bilge Pump Controls