technical article from Blue Sea Systems
The combination of the Dual Circuit Plus™ Battery Switch and CL-Series BatteryLink™ ACR provides a practical and inexpensive solution to isolated battery circuits, emergency parallel backup operation, and automated charge management.
The diagrams below indicate how to connect the Dual Circuit Plus™ battery switch and BatteryLink™ ACR when:
- The house battery bank is connected to the charging source
- The start battery bank is connected to the charging source
To sense the voltage level of the battery bank connected to your boat's charging source,
- Connect terminal A to the battery bank connected to the charging source.
- Connect terminal B to the battery bank not connected to the charging source.
- Connect terminal 3 to the main negative bus or the negative terminal of the nearest battery.
To sense the voltage level of both battery banks,
- Connect a jumper wire from terminal 1 to terminal B.
House Battery Bank Connected to Charging Source
Start Battery Bank Connected to Charging Source
The Dual Circuit Plus™ Battery Switch simplifies multi-bank battery switching with a single ON/OFF switch. The Dual Circuit™ Battery Switch is available with a COMBINE BATTERIES position (Dual Circuit Plus™) and without (Dual Circuit). Switch positions provide the following functionality.
When the Dual Circuit™or Dual Circuit Plus™ Battery Switches is set to ON, current flows from the start battery bank to the start circuit, and from the house battery bank to the house circuits.
When the Dual Circuit™ or Dual Circuit Plus™ Battery switches is set to COMBINE BATTERIES, current flows from both house and start battery banks to house and start circuits. The COMBINE BATTERIES function offers the ability to combine the two battery banks in the event of a low start battery.
When combined with the Dual Circuit Plus™ Battery Switch, the CL-Series BatteryLink™ ACR fully automates the charging of two battery banks. Battery management, which was at one time difficult for many boaters, is now simple. The boat owner simply turns the battery switch to the ON position when arriving on the boat, and turns it to the OFF position when leaving. Boaters no longer have to worry about which batteries are charging or discharging. More than just a battery isolator, the BatteryLink™ ACR automatically connects batteries during the charging cycle and disconnects them under discharge.
The BatteryLink™ ACR has two parts:
- A relay - a switch that is activated by an electrically powered magnetic coil.
- An electronic circuit that senses the voltage level of the boat's batteries and signals the relay switch:
- Closed when voltage is high (the ACR's COMBINE voltage)
- Open when voltage is lower (the ACR's UNDERVOLTAGE voltage)
When the sensed voltage is below the COMBINED voltage level (default setting of 13.5 volts), the relay is open. The batteries are not connected and all electrical loads are on one battery while the second battery bank is isolated. When the sensed voltage is 13.5 volts and has remained at that level for at least 30 seconds, the batteries are combined together. When combined, both battery banks are charged. When the sensed voltage drops below the UNDERVOLTAGE level (default setting of 12.7 volts) for 60 seconds, the relay opens. The house battery bank is not being charged. If the house battery bank is being discharged through loads connected to it, the start battery bank is isolated and will retain its charge.
Original article from Blue Sea Systems