12V/24V 100A Buck-Boost DC/DC Converter

⚡ VICTRON 12V/24V 100A BUCK-BOOST DC/DC CONVERTER

High-Current Programmable DC-DC Service Battery Charger – 12V & 24V Systems, Smart Alternator Compatible, Engine-Running Detection & Input Current Limiting

⚡ The Victron 12V/24V 100A Buck-Boost DC/DC Converter is a high-current programmable charging solution designed for compatible 12V and 24V service-battery systems in vehicles equipped with modern intelligent or smart alternators.

Modern smart alternators, including systems associated with regenerative braking and Euro 5 and Euro 6 engines, can vary their output voltage considerably while the engine is running. This can make direct auxiliary-battery charging unreliable because the vehicle electrical system may not consistently provide the voltage required for effective charging.

The Victron Buck-Boost addresses this by regulating the vehicle supply and providing the service battery with a programmed charging voltage. It can be configured for compatible 12V or 24V auxiliary batteries supplied from either a 12V or 24V alternator and starter-battery system.

The product designation identifies this as the high-capacity 100A model. Actual output current is determined by the programmed maximum charge-current setting, maximum input-current setting and the converter's operating-temperature limits.

A built-in engine-running detection system helps prevent deep discharge of the starter battery, while programmable D+, CAN bus* or (+)15 activation can be used where an alternative control method is required.

---

⚡ KEY FEATURES

⚡ 100A Buck-Boost Model
The product designation identifies this unit as the 100A version of Victron's programmable Buck-Boost DC/DC converter range.

🔋 Designed for Service Battery Charging
Designed specifically for charging compatible 12V or 24V auxiliary/service batteries from a vehicle electrical system.

🚗 Smart Alternator Compatible
Suitable for compatible intelligent-alternator applications, including vehicle systems associated with regenerative braking and Euro 5 and Euro 6 engines.

⬆️⬇️ Buck-Boost Voltage Regulation
Designed to regulate the charging supply when vehicle voltage may be either above or below the required auxiliary-battery charging voltage.

🔋 12V or 24V Auxiliary Battery
Can be programmed for compatible 12V or 24V service-battery systems.

🔌 12V or 24V Vehicle Source
Can be configured for use with compatible 12V or 24V alternator and starter-battery electrical systems.

🚦 Built-In Engine-Running Detection
Helps avoid deep discharge of the vehicle's starting battery by controlling when the converter is permitted to operate.

🎛️ Programmable External Activation
Can alternatively be activated using a programmable D+, CAN bus* or (+)15 connection according to the supplied information.

💻 Fully PC Programmable
Operating parameters can be configured using a PC application.

🔌 USB Programming Connection
Programming requires a USB Type-A male to USB Type-B male cable according to the supplied information.

⚡ Programmable Charge-Current Limit
Maximum charging current can be configured to suit the auxiliary-battery and electrical-system requirements.

🔌 Programmable Input-Current Limit
Maximum current drawn from the source electrical system can also be limited.

🌡️ Temperature-Based Current Limiting
Available output current is also influenced by the maximum operating-temperature limit of the converter.

💡 Input Status LED
Provides clear indication of converter operation, low input voltage, engine-running detection and over-temperature conditions.

💡 Output Status LED
Provides indication of converter operation and auxiliary-battery voltage condition.

---

🚗 DESIGNED FOR INTELLIGENT & SMART ALTERNATORS

Traditional alternators generally provide a relatively stable charging voltage while the engine is running.

Modern intelligent alternators can behave differently. Their output is controlled by vehicle electronics and can rise or fall considerably according to driving conditions, battery condition, emissions strategy, regenerative braking and other vehicle requirements.

The supplied product information specifically identifies applications involving:

• 🚗 Smart or intelligent alternators
• ♻️ Regenerative-braking systems
• ⚙️ Euro 5 engine applications
• ⚙️ Euro 6 engine applications

The Buck-Boost converter provides a controlled charging supply to the auxiliary battery despite these changing vehicle-system conditions.

⚠️ IMPORTANT: Euro 5 or Euro 6 classification alone does not identify the exact charging strategy of a particular vehicle. Confirm the vehicle's actual alternator and electrical-system behaviour before installation.

---

⬆️⬇️ BUCK-BOOST DC-DC CHARGING

The Buck-Boost design allows the converter to regulate charging when the source voltage may be either higher or lower than the voltage required by the service battery.

The converter charges the auxiliary battery using a programmed charge voltage rather than relying directly on the varying voltage produced by the vehicle alternator.

The supplied product information gives approximately 15.4V on some Mercedes applications as an example of a higher vehicle-system voltage that can occur.

The Buck-Boost system is designed to manage both these higher voltages and lower smart-alternator voltages to provide a more controlled service-battery charging supply.

---

🔋 FLEXIBLE 12V & 24V SYSTEM CONFIGURATION

The supplied product information states that the converter can be programmed to charge either a 12V or 24V auxiliary battery from either a 12V or 24V alternator and starter-battery system.

Compatible system arrangements can therefore include:

• 12V vehicle system → 12V service battery
• 12V vehicle system → 24V service battery
• 24V vehicle system → 12V service battery
• 24V vehicle system → 24V service battery

This flexibility makes the Buck-Boost suitable for a broad range of compatible vehicle and specialist electrical-system configurations.

⚠️ IMPORTANT: Correct programming is essential. The source-system voltage and auxiliary-battery voltage must be configured correctly before operation.

---

⚡ HIGH-CURRENT 100A MODEL

The product designation identifies this converter as the 100A model.

The supplied information also states that output current is determined by three key factors:

• Maximum charge-current setting
• Maximum input-current setting
• Maximum operating-temperature limit of the converter

This means the converter will not necessarily deliver 100A under every operating condition.

The programmed current settings, source-system capability, auxiliary-battery requirements and converter temperature all need to be considered.

⚠️ IMPORTANT: The supplied information does not include a complete electrical specification table confirming detailed continuous, peak or temperature-dependent output-current ratings. Where exact current capability is critical, confirm the current Victron technical documentation for this exact 100A model.

---

🚦 BUILT-IN ENGINE-RUNNING DETECTION

The Buck-Boost incorporates an engine-running detection system.

This function is designed to help prevent deep discharge of the vehicle's starter battery by controlling when the converter is allowed to begin auxiliary-battery charging.

This is especially valuable in modern smart-alternator vehicles where source voltage may not behave like a conventional fixed-voltage alternator system.

---

🎛️ ALTERNATIVE PROGRAMMABLE ACTIVATION

Instead of relying solely on the built-in engine-running detection system, the converter may be activated using a programmable input.

The supplied product information lists:

• D+ signal
• CAN bus*
• (+)15 connection

This allows the converter to be integrated with compatible vehicle-control arrangements where required.

⚠️ IMPORTANT: The supplied source references CAN bus with an asterisk but does not provide the associated compatibility note. Do not assume direct connection to any vehicle CAN network is supported. Check the applicable Victron documentation first.

---

💻 FULLY PROGRAMMABLE BY PC

The converter can be fully programmed through a PC application according to the supplied information.

This allows the charging system to be configured around the vehicle electrical system and auxiliary battery rather than relying on one fixed operating arrangement.

Programming requires:

USB Type-A male to USB Type-B male cable

⚠️ IMPORTANT: The supplied information states that the USB cable is required but does not state that the cable is included with the converter.

---

⚡ PROGRAMMABLE CHARGE-CURRENT LIMIT

The maximum charge-current setting is one of the main parameters determining converter output current.

This allows the charging rate to be matched to the requirements of the service battery and the overall system.

This is particularly important with a high-capacity 100A-class converter because not every battery is designed to accept such a high charge current.

⚠️ IMPORTANT: Never assume that a battery can safely accept 100A simply because the converter is the 100A model. Confirm the battery manufacturer's maximum and recommended charging-current specifications.

---

🔌 PROGRAMMABLE INPUT-CURRENT LIMITER

The converter also allows the maximum input current to be limited.

This can help configure the converter's demand around the capacity of the vehicle alternator and source electrical system.

Factors that should be considered include:

• Alternator output capacity
• Existing vehicle electrical loads
• Starter-battery condition
• Source voltage
• Input cable size
• Cable length and voltage drop
• Required auxiliary-battery charging current

⚠️ IMPORTANT: The input-current setting should be determined as part of the complete vehicle electrical-system design. A high-current converter can place substantial demand on the vehicle charging system.

---

🌡️ TEMPERATURE-DEPENDENT OUTPUT

The supplied information states that the converter's maximum operating-temperature limit is another factor determining available output current.

If operating temperature becomes excessive, the available charging current may be reduced.

Correct converter location, airflow and thermal management are particularly important with a high-current 100A model.

---

💡 INPUT STATUS LED INDICATION

The converter includes colour-coded input-side status indication.

🟢 Green – Converter On
Indicates that the converter is operating.

🟡 Yellow – Input Voltage Below Threshold
The converter is off because input voltage is below the required threshold.

🔴 Red – Over Temperature
The converter is off because an over-temperature condition has been detected.

🔵 Blue – Quick Flash
Engine running has been detected and the converter will start after the preset delay.

🔵 Blue – Slow Flash
The converter is off and activation is blocked because input voltage is too low.

---

💡 OUTPUT STATUS LED INDICATION

The output-side LED provides information about converter operation and service-battery condition.

🟢 Green – Converter Off / Battery Voltage Normal
According to the supplied information, the converter is off and the service-battery voltage is considered normal.

🟡 Yellow – Converter Off / Battery Voltage Low
Indicates that the converter is off and the service-battery voltage is low.

🔴 Red – Battery Discharged or Not Connected
Indicates that the converter is off and the battery is either discharged or not connected.

🟣 Purple – Converter On
Indicates that the converter is operating.

---

🔋 CONTROLLED SERVICE-BATTERY CHARGING

The Buck-Boost is specifically designed around vehicle service-battery charging.

Instead of allowing the auxiliary battery to simply follow the vehicle-system voltage, the converter supplies a programmed charging voltage.

This helps provide controlled charging despite the variable voltage behaviour of modern intelligent alternators.

⚠️ IMPORTANT: The supplied information does not provide battery-chemistry-specific charge voltages or charging profiles. Configure the converter according to the battery manufacturer's requirements and applicable Victron instructions.

---

🔋 STARTER-BATTERY PROTECTION

The built-in engine-running detection system is specifically intended to help prevent deep discharge of the vehicle's starting battery.

By controlling converter activation, the system helps ensure auxiliary-battery charging occurs only when suitable operating conditions are detected.

---

⚡ MANAGES HIGH & LOW VEHICLE VOLTAGE

The supplied product information states that the converter charges the auxiliary battery using a pre-set voltage while eliminating the effects of excessively high or low vehicle-system voltages.

An example of approximately 15.4V on some Mercedes applications is specifically provided in the supplied information.

The converter's Buck-Boost function is designed to maintain suitable service-battery charging despite these source-voltage changes.

---

🚙 4WD & HIGH-DEMAND TOURING SYSTEMS

The 100A Buck-Boost may suit compatible high-capacity 4WD auxiliary-battery systems where significant alternator charging performance is required.

Potential compatible applications include:

• 🔋 Large auxiliary-battery banks
• 🏕️ High-demand touring electrical systems
• ❄️ Fridge and accessory battery systems
• ⚡ High-power auxiliary installations
• 🔌 Compatible 24V service-battery systems

⚠️ IMPORTANT: A high-capacity battery bank does not automatically mean it should be charged at 100A. Check the battery manufacturer's charging-current limits.

---

🚐 CAMPERVANS & MOTORHOMES

The ability to work with compatible 12V and 24V source and service-battery configurations can make the Victron Buck-Boost useful in larger campervan, motorhome and specialised touring electrical systems.

The programmable input-current limiter can also help tailor the charging demand to the capability of the vehicle's alternator and electrical system.

---

🚚 COMMERCIAL & SPECIALIST VEHICLES

The high-current 100A platform can also suit compatible commercial, specialist and service-vehicle applications requiring substantial auxiliary-battery charging.

Potential compatible applications include:

• 🚚 Commercial vehicles
• 🚑 Specialist and service vehicles
• 🛠️ Mobile workshops
• 🏗️ Machinery and mobile equipment
• 📡 Communications installations
• 🔋 High-capacity auxiliary-battery systems

---

⚠️ HIGH-CURRENT ELECTRICAL SYSTEM DESIGN

A 100A-class DC-DC charging installation requires careful electrical-system design.

At this level of charging current, cable size, connection quality, voltage drop, alternator capacity and circuit protection become particularly important.

Important installation considerations include:

• Vehicle alternator output capability
• Vehicle's existing electrical demand
• Starter-battery condition and capacity
• Service-battery maximum charge-current rating
• Service-battery chemistry and charging voltage
• Input-current configuration
• Charge-current configuration
• Input cable size
• Output cable size
• Cable-run length
• Allowable voltage drop
• High-quality cable terminations
• Correct circuit protection
• Converter cooling and ventilation

⚠️ IMPORTANT: The supplied information does not nominate cable sizes, terminal specifications or fuse ratings for this exact model. These must be confirmed from the current manufacturer documentation and calculated for the installation.

---

🔋 BATTERY COMPATIBILITY

The supplied information confirms that the converter is programmable for service-battery charging but does not provide specific battery-chemistry settings.

Before installation, confirm:

• Battery nominal voltage
• Required charging voltage
• Maximum permitted charge current
• Recommended charge current
• Battery-management-system limitations where applicable
• Battery manufacturer's charging requirements

⚠️ IMPORTANT: Do not assume AGM, GEL, flooded lead-acid and lithium batteries should all use the same settings.

---

📋 PRODUCT INFORMATION SUMMARY

Product: Victron 12V/24V 100A Buck-Boost DC/DC Converter

Product type: Programmable high-current vehicle DC-DC service-battery charging converter

Product designation: 100A

Service-battery voltage: Programmable for compatible 12V or 24V systems

Alternator / starter-battery system: Programmable for compatible 12V or 24V systems

Smart alternator support: Yes – according to supplied product information

Regenerative-braking applications: Yes

Euro 5 / Euro 6 applications: Yes

Engine-running detection: Built in

Alternative programmable activation: D+, CAN bus* or (+)15 according to supplied information

PC programmable: Yes

Programming cable required: USB Type-A male to USB Type-B male

Maximum charge-current setting: Programmable

Maximum input-current setting: Programmable

Temperature-related output limitation: Yes

Input-status LED: Yes

Output-status LED: Yes

⚠️ SPECIFICATION NOTE: The supplied information does not include a complete electrical specification table for this exact 100A model. Exact dimensions, weight, terminal arrangement, IP rating, voltage ranges, detailed efficiency figures and continuous/peak current specifications have therefore not been added.

---

⚠️ INSTALLATION & COMPATIBILITY CHECKLIST

Before purchasing or installing the Victron 12V/24V 100A Buck-Boost DC/DC Converter, confirm the requirements of the complete vehicle and auxiliary-battery system.

• Vehicle source voltage confirmed
• Service-battery nominal voltage confirmed
• Vehicle smart-alternator behaviour identified
• Battery chemistry confirmed
• Battery charging voltage confirmed
• Battery maximum charge-current rating confirmed
• Vehicle alternator capacity assessed
• Existing vehicle electrical loads considered
• Maximum charge-current setting configured correctly
• Maximum input-current setting configured correctly
• Correct input cable sizing
• Correct output cable sizing
• Voltage drop calculated
• Appropriate circuit protection selected
• Correct engine-running detection configuration
• Correct programmable activation input where used
• Suitable PC programming connection available
• Adequate ventilation and mounting space
• Correct polarity confirmed before connection

⚠️ IMPORTANT: A 100A-class converter can place a very substantial load on the vehicle charging system. Alternator capacity and vehicle electrical demand should be assessed before installation.

⚠️ IMPORTANT: Do not configure the converter for 100A charging unless the service battery, source system, wiring and protection are all suitable for that current.

⚠️ IMPORTANT: The supplied information does not nominate cable sizes or fuse ratings. These must be determined for the actual installation and confirmed against the manufacturer's current installation requirements.

⚠️ IMPORTANT: Battery charging voltage and current must be configured according to the specific battery manufacturer's requirements.

---

❓ FREQUENTLY ASKED QUESTIONS

What is the Victron 12V/24V 100A Buck-Boost Converter designed for?

It is designed for charging compatible 12V or 24V service batteries from vehicle electrical systems, including vehicles fitted with intelligent or smart alternators.

Is this the 100A model?

Yes. The supplied product designation identifies this version as the 100A Buck-Boost DC/DC Converter.

Will it always charge at 100A?

No. The supplied information states that actual output current is determined by the maximum charge-current setting, maximum input-current setting and the converter's maximum operating-temperature limit.

Can every battery accept 100A charging?

No. Maximum acceptable charging current depends on the exact battery, its capacity, chemistry, BMS and manufacturer specifications.

Why is a Buck-Boost charger useful with a smart alternator?

Smart alternators can significantly vary their output voltage while the vehicle is operating. The Buck-Boost regulates this changing source into a controlled charging supply for the service battery.

Does it work with Euro 5 and Euro 6 vehicles?

The supplied product information specifically identifies Euro 5 and Euro 6 applications, including vehicles using regenerative-braking systems.

Does every Euro 5 or Euro 6 vehicle have the same alternator system?

No. Alternator control strategies vary between vehicle manufacturers, models and configurations. Confirm the actual vehicle charging system before installation.

What does Buck-Boost mean?

It refers to the converter's ability to regulate charging when the source voltage can be either above or below the voltage required by the service battery.

Can it charge a 12V auxiliary battery?

Yes. The supplied information states that the converter can be programmed for compatible 12V service-battery systems.

Can it charge a 24V auxiliary battery?

Yes. The supplied information also states that it can be programmed for compatible 24V service-battery systems.

Can it operate from a 12V vehicle?

Yes. It can be configured for a compatible 12V alternator and starter-battery source according to the supplied information.

Can it operate from a 24V vehicle?

Yes. It can also be configured for a compatible 24V source system.

Can it charge a 24V battery from a 12V source?

The supplied information states that a 24V auxiliary battery can be charged from either a 12V or 24V alternator and starter-battery system when correctly programmed.

Can it charge a 12V battery from a 24V source?

Yes. The supplied information states that it can also be configured for a 12V service battery supplied from a compatible 24V source system.

How does it know when the engine is running?

The converter includes a built-in engine-running detection system.

Why is engine-running detection important?

It helps prevent unnecessary discharge of the vehicle's starting battery by controlling when the converter is permitted to charge the service battery.

Can I use an ignition or D+ signal instead?

The supplied information states that the converter can alternatively be activated using a programmable D+, CAN bus* or (+)15 connection.

Can it connect directly to any vehicle CAN bus?

Do not assume this. The supplied source references CAN bus with an asterisk but does not include the associated compatibility information. Check the current Victron documentation before using this method.

Can the converter be programmed?

Yes. The supplied information states that it is fully programmable using a PC application.

What cable is needed for programming?

A USB Type-A male to USB Type-B male cable is required according to the supplied information.

Is the programming cable included?

The supplied information states that the cable is required but does not state that it is included.

Can the charging current be reduced below 100A?

The supplied information states that maximum charge current is programmable, so charging can be limited according to system requirements.

Can I limit the current drawn from the alternator?

Yes. The supplied information states that maximum input current can also be configured.

Why would I limit input current?

Input-current limiting can help manage the load placed on the alternator and source electrical system.

Will my standard alternator support a 100A Buck-Boost charger?

That cannot be assumed. Alternator output capacity, existing vehicle loads, operating conditions and converter settings must all be assessed.

Does temperature affect charging current?

Yes. The supplied information states that the converter's operating-temperature limit is one of the factors determining output current.

What does a green input LED mean?

Green indicates that the converter is on.

What does a yellow input LED mean?

Yellow indicates that input voltage is below the required threshold and the converter is off.

What does a red input LED mean?

Red indicates an over-temperature condition and the converter is off.

What does a quickly flashing blue input LED mean?

It indicates that engine running has been detected and the converter will start after the preset delay.

What does a slowly flashing blue input LED mean?

It indicates that the converter is off and activation is blocked because input voltage is too low.

What does a green output LED mean?

According to the supplied information, green indicates that the converter is off and service-battery voltage is normal.

What does a yellow output LED mean?

Yellow indicates that the converter is off and the service-battery voltage is low.

What does a red output LED mean?

Red indicates that the converter is off and the battery is discharged or not connected.

What does a purple output LED mean?

Purple indicates that the converter is on.

Can it charge AGM batteries?

The supplied information confirms programmable service-battery charging but does not provide AGM-specific parameters. Configure the converter according to the battery manufacturer's charging specifications.

Can it charge lithium batteries?

The supplied information does not specifically confirm lithium compatibility or provide lithium-specific settings. Confirm compatibility with the exact battery, BMS and current Victron documentation before installation.

Can it charge a large lithium battery bank at 100A?

Potentially only where the exact battery bank and BMS are rated to accept that charging current and the source electrical system can support it. Do not assume compatibility solely from battery capacity.

Does it protect the vehicle starter battery?

The built-in engine-running detection system is specifically intended to help avoid deep discharge of the starting battery.

Can I use it in a 4WD?

Potentially. It may suit compatible high-demand 4WD auxiliary-battery systems where smart-alternator charging and substantial charge current are required.

Can I use it in a campervan or motorhome?

Potentially. Its programmable 12V/24V operation and smart-alternator support can make it suitable for compatible campervan and motorhome service-battery systems.

Can I use it in a commercial vehicle?

Potentially. Its programmable system voltage and high-current charging capability can suit compatible commercial and specialist vehicle installations.

What cable size should I use?

The supplied information does not nominate a cable size for this exact model. Cable must be selected according to actual configured current, system voltage, cable length, allowable voltage drop and manufacturer requirements.

What fuse size should I use?

The supplied information does not specify fuse ratings. Circuit protection should be selected according to the actual installation, cable capacity, converter configuration and current Victron requirements.

Why is correct cabling especially important with the 100A model?

High-current electrical systems can experience significant voltage drop and heating if cable size or connections are inadequate. Correctly sized cable, quality terminations and appropriate protection are essential.

What should I check before ordering?

Confirm the vehicle source voltage, service-battery voltage, smart-alternator behaviour, battery chemistry, permitted charging current, alternator capacity, input-current requirements, control method, cable sizing, circuit protection and installation requirements before purchase.

---

⚡ SERIOUS HIGH-CURRENT CHARGING FOR MODERN 12V & 24V VEHICLE SYSTEMS

The Victron 12V/24V 100A Buck-Boost DC/DC Converter is designed for demanding auxiliary-battery installations where smart-alternator behaviour, high charging demand and system flexibility require more than a basic voltage-sensitive charging setup.

With Buck-Boost voltage control, programmable 12V and 24V source and service-battery configurations, built-in engine-running detection, programmable D+ / CAN bus* / (+)15 activation, PC configuration, adjustable charge-current control and adjustable input-current limiting, it provides a highly configurable charging platform for compatible modern vehicles and specialist electrical systems.

A 100A-class charging installation requires careful system design. Confirm the battery's allowable charging current, vehicle alternator capacity, input-current configuration, cable sizing, circuit protection, control method and thermal installation requirements before operation.