Victron SolidSwitch 104

The SolidSwitch 104 is a solid state switch that turns a DC load of up to 70V and 4A on and off from a low power digital control signal. Because it is solid state rather than a mechanical relay, its standby draw is tiny, around 0.04Ah per month, compared with 10Ah or more for a small relay. That makes it ideal in a lithium system where the control circuit is permanently powered.

It has three typical uses. It can control an external alternator regulator, such as a Balmar or Mastervolt Alpha Pro, in a Victron lithium system. It can switch an ordinary DC load such as a light, drawing only about 100 microamps from the control circuit while switching up to 4A. And it can increase the number of chargers that can be wired to the allow to charge (ATC) output of a Victron BMS, keeping the parasitic load down to the order of the battery bank self discharge.

The load can be resistive, capacitive or inductive, including the coil of a high power contactor. Small, efficient and versatile, the SolidSwitch 104 is a useful accessory when integrating alternators, extra chargers or switched loads into a Victron lithium BMS system.