Pre-Charge Circuit with Remote Push Button Switch (48" Lead)

Large inverter systems contain internal capacitors that can draw a significant amount of current when DC power is first connected. This brief inrush can create arcing at switches and connectors, place added stress on electrical components, or cause some lithium battery management systems to interpret the surge as a short circuit.

The MobileMustHave Pre-Charge Circuit provides a controlled way to charge the inverter’s internal capacitors before applying full DC power. It combines a momentary push-button switch, an inline 25W 100-ohm wirewound resistor, and a pre-wired 48-inch cable assembly suitable for a variety of mobile and off-grid power applications.

This kit is typically used with larger inverter systems above 3000VA and can help support a cleaner, more controlled startup process when the inverter has been disconnected from DC power.

Best For

• Victron inverter and inverter/charger systems typically above 3000VA
• Large lithium battery banks with high-current DC distribution
• RV, van, marine, overland, and off-grid power installations
• Systems that experience battery BMS shutdown during inverter connection
• Installers who want a remote momentary pre-charge switch

Core Features

• Helps limit inverter inrush current before the main DC connection is closed
• May reduce arcing and electrical stress at switches, terminals, and connectors
• Momentary push-button switch provides simple manual pre-charge control
• Integrated 25W, 100-ohm wirewound resistor with ±5% tolerance
• 220V resistor working voltage and 220V maximum overload voltage
• 48 inches of total pre-wired cable for flexible installation
• Includes 12 inches of cable on one end, 6 inches between the switch and resistor, and 30 inches after the resistor
• Suitable for a variety of professional-grade mobile and off-grid inverter applications

How the Pre-Charge Circuit Is Used

Before applying full DC power to an inverter that has been disconnected, press and hold the momentary switch for approximately 5–10 seconds. This allows the inverter’s internal capacitors to charge gradually through the resistor. Release the button, then turn on the main DC power supply to the inverter.

Installation should be completed only by someone familiar with high-current DC electrical systems. Follow the included instructions, the inverter manufacturer’s requirements, and all applicable electrical and safety practices.

Inverter Pre-Charge Kit Instructions.pdf