Introduction
The Manson SBC-7130 is a high quality PV charge controller, at a price point almost unrivalled in its class. The unit provides an LCD readout of the various system statuses.
Features
The SBC-7130 is feature packed and the various threshold voltage limits can be arbitarily adjusted thanks to its microprocessor control.
The LCD cycles through each parameter, displaying in turn: the mode of operation, battery voltage, PV voltage, PV amperes, today's ampere hours, yesterday's ampere hours and the day before's ampere hours.
A dual-colour LED provides a quick visual status of the battery state.
Heavy duty terminals are provided to connect heavy guage wire (up to 10AWG) to the unit.
Internally, a 40A automotive-type blade fuse provides overload protection. A spare 40A fuse is provided.
Operation
The unit automatically determines the state of the battery and applies an appropriate charging regime. It uses a three stage Bulk/Absorption/Float charging system. The Absorption and Float voltages can be set anywhere from 12.0v up to 16.5v. When the battery voltage drops below the float level for more than 5 minutes, the unit will commence bulk charging. Once the absorption voltage has been reached, it will hold the charging voltage constant for one hour, then switch to float mode.
Performance
For a typical day consisting of 5 hours of useful sunlight, and with enough panels to provide 30A of short circuit current, the SBC-7130 can theoretically deliver up to 150 AH of charging current per day. For a 12 volt battery, this equates to at least 1800 watt-hours of charge per day though the controller.
At near full load, the integral chassis/heatsink becomes very warm to the touch. The heating is less pronounced when the PWM charge is at 100% duty cycle, which vastly reduces power dissipation in the MOSFETs.
Its quiescent current draw of 15mA makes it unsuitable for small battery banks (less than 10 AH) due to the overnight discharge. The microprocessor and battery status LED requires constant power to keep running. If the battery is disconnected overnight, the rolling three-day ampere-hour statistics will be lost.