Votronic VBCS 30/20/400 Triple HV CI 3270 – 30A B2B Charging Converter, 20A AC Charger, and 400Wp MPPT Solar Charge Controller

The Votronic VBCS 30/20/400 Triple HV CI (MPN: 3270) combines three key charging functions for 12-V vehicle electrical systems in a single unit—a 30-A B2B charge converter, a 20-A AC charger, and an MPPT solar charge controller for solar systems up to 400 Wp. This combined unit is designed for motorhomes, travel trailers, and specialty vehicles and automatically charges the onboard battery while driving, when connected to the mains, or via connected solar modules. By combining the three charging sources, it reduces the space, wiring, and installation requirements compared to separate individual devices.

Three charging functions combined in a compact unit for the 12-V onboard electrical system

• 3-in-1 unit combination: B2B charge converter, AC charger, and MPPT solar charge controller
• Up to 30 A B2B charging current while driving
• Up to 20 A AC charging current for the onboard battery
• MPPT solar charge controller for 50–400 Wp module power
• Maximum 15 A solar module current and 50 V solar open-circuit voltage (Voc)
• Charging programs for lead-acid, gel, AGM, and LiFePO4 batteries
• Microprocessor-controlled IU1oU2oU3 charging technology
• Suitable for modern alternators, including Euro 6 vehicles
• Temperature compensation for lead-acid batteries and temperature-dependent LiFePO4 protection
• CI-BUS-compatible for integration into compatible on-board management systems
• Connections for LCD Charge Control S and VBS2
• AES switching output for controlling compatible refrigerators
• AC power limit to restrict mains power consumption
• Temperature sensor 825 included

30-A B2B charging converter for charging the battery while driving

The integrated B2B charging converter supplies the onboard battery with controlled power from the vehicle’s starter circuit while driving. For this unit combination, the maximum charging current is 30 A. The permissible voltage range of the starter battery or alternator is between 10.5 and 16.5 V, with a maximum input current of 42 A. The system is also designed for vehicles with modern, voltage-regulated alternators. Activation can be triggered via D+ or a corresponding ignition signal. Additionally, the maximum input current of the charge converter can be limited to 25 A. For caravan operation, limits of 19 A and 14 A are available. The control system takes the status of the vehicle’s electrical circuit into account. If the starter battery or alternator voltage is low, or if the load is high, the charge converter can reduce its power consumption. This ensures that the auxiliary battery is charged without placing an unnecessarily heavy load on the starter circuit.

20-A Mains Charger for Shore Power and Campsites

If a mains connection is available, the integrated charger takes over the supply to the onboard battery. The rated operating voltage is 110–230 V AC at 45–65 Hz at full charging power. The operating voltage range is 90 to 270 V AC; voltages up to 305 V AC are permitted for brief periods of up to five seconds. The maximum power consumption of the Model 3270 is 360 W. When operating on the mains, a maximum charging current of 20 A is available for the onboard battery. Up to an additional 4 A can be routed to the starter battery via the integrated charge current distributor. This helps maintain the vehicle battery’s charge, particularly during extended periods of inactivity. The AC Power Limit function allows the power consumption from the mains to be specifically limited. This is relevant, for example, when using under-fused power connections at parking areas or campgrounds.

MPPT Solar Charge Controller for up to 400 Wp

An MPPT solar charge controller is integrated directly into the unit for use with a solar system. Solar modules with a total power output of 50 to 400 Wp can be connected. The maximum permissible module current is 15 A, and the maximum open-circuit voltage is 50 V Voc. The maximum solar charging current is specified as 29 A for the service battery and 4 A for the starter battery. The controller continuously determines the optimal operating point for the connected solar modules and adjusts it to changing irradiance and temperature conditions. This allows the available solar energy to be used directly to charge the battery without the need for a separate solar charge controller. When the service battery is at an appropriate state of charge, any excess solar power is also used to charge the starter battery.

Nine charging programs for various battery technologies

A total of nine charging programs are available for the onboard battery. Lead-acid, gel, AGM, and LiFePO4 batteries are supported. The documentation distinguishes between four charging curves for lead-acid batteries and five charging programs for LiFePO4 systems. The selection is made using the switches on the front of the unit and must be set to match the type of battery being used. The microprocessor-controlled IU1oU2oU3 charging curve operates in several charging phases. For lead-acid batteries, the included temperature sensor ensures that the charging voltage is adjusted based on temperature. For LiFePO4 batteries, temperature monitoring serves, among other things, as protection against excessively low or high battery temperatures. Votronic explicitly requires a suitable battery management system (BMS) with the necessary safety circuits for LiFePO4 operation.

CI-BUS, External Display, and AES Switching Output

The VBCS 30/20/400 supports the CI-BUS and can therefore be integrated into compatible on-board management systems. This allows relevant device data to be made available in the central vehicle system and, depending on the system, various functions to be controlled. Additionally, the device features connections for the LCD-Charge Control S and VBS2. A compatible refrigerator with an Automatic Energy Selector can be controlled via the built-in AES switching output. If sufficient solar power is available, excess solar energy can be used to power the refrigerator’s 12-V operation. Alternatively, this output can also be used to power small 12-V loads.

Protection Features and Installation

According to the manufacturer, the microprocessor-controlled monitoring system includes various protective mechanisms, such as protection against overload, overheating, overvoltage, and short circuits. In addition, the system prevents, among other things, reverse discharge of the batteries and unwanted discharge of the starter battery when the engine is off. Via voltage sensor wires, the device can measure the battery voltage directly at the batteries. This allows voltage losses in the charging lines to be taken into account during regulation.

Technical Specifications

• Onboard battery: 12 V
• Supported battery types: Lead-acid, gel, AGM, LiFePO4
• Number of charging programs: 9
• Recommended lead-acid battery capacity: 45–280 Ah
• Starter battery: 12 V, >60 Ah recommended
• Nominal AC voltage: 110–230 V AC / 45–65 Hz
• Mains operating voltage range: 90–270 V AC
• Short-term permissible AC voltage: 305 V AC / 5 s
• Max. power consumption from the mains: 360 W
• Max. AC charging current for on-board battery: 20 A
• Charging current for starter battery via charge current distributor: 4 A
• B2B system: 12 V / 12 V
• Max. B2B charging current for the onboard battery: 30 A
• Starter battery/alternator voltage range: 10.5–16.5 V
• Max. B2B input current: 42 A
• Adjustable maximum current limit: 25 A
• RV current limit: 19 A / 14 A
• Solar controller: MPPT
• Solar module power: 50–400 Wp
• Max. solar module current: 15 A
• Max. solar open-circuit voltage (Voc): 50 V
• Max. solar charging current for on-board/starter battery: 29 A / 4 A
• OK signal output: 12 V / 1 A
• Ambient temperature: -20 to +45 °C
• Humidity: max. 95% relative humidity, non-condensing
• Protection class: I
• Protection rating: IP2X
• Weight: 2.7 kg
• Dimensions (L × W × H): 256 × 219 × 85 mm

Package Contents

1x Votronic VBCS 30/20/400 Triple HV CI
1x power cord with IEC connector
1x Temperature Sensor 825
1x Installation and Operating Instructions