Bespoke Pre-Built Victron Energy Power Board & Off-Grid Solar Electrics Kit for Tiasvanlife’s LWB Sprinter Campervan Build

Converting a commercial panel van into a fully functional campervan requires careful planning around energy generation, storage, and space utilisation. When van life blogger Tia (Tiasvanlife) embarked on converting a 2021 Long Wheel Base (LWB) Mercedes Sprinter, creating a dependable, high-performance off-grid electrical system was central to the build. Living and working on the road requires clean, continuous power to run household appliances, charge filming equipment, and operate essential onboard amenities without total reliance on campsite mains hook-ups.

To meet these demands, Callidus Trade supplied a custom pre-built power board engineered around their flagship KIT37 Victron Energy system. Custom-manufactured to contour precisely around the Sprinter’s near-side wheel arch, the board combines 855W of roof-mounted solar generation, heavy-duty 3kVA AC inverter power, intelligent alternator DC-DC charging, and advanced Victron smart monitoring. This case study details how a bespoke pre-assembled power solution enables seamless off-grid campervan living while removing the complexity of self-install electrical wiring.

Project Background: Navigating Campervan Electrics Challenges

Campervan conversions pose unique electrical engineering challenges compared to stationary off-grid buildings. Space inside a Mercedes Sprinter is highly valuable, requiring electrical components to be installed compactly without restricting living area or storage space. Furthermore, DIY van builders face complex wiring requirements when trying to integrate multiple power sources - solar panels, vehicle alternators, and 230V mains shore power - into a single safe, unified circuit.

Key requirements identified for the Tiasvanlife Mercedes Sprinter build included:

• Tailored Wheel Arch Mounting: The power system needed to fit neatly around the near-side (N/S) rear wheel arch of the 2021 LWB Sprinter, utilising an exact 142cm x 80cm footprint (130cm x 75cm usable surface) to keep main living areas unencumbered.
• High Peak AC Load Capability: Running 230V household devices  - such as hairdryers, blenders, laptops, and power tools - demanded a robust pure sine wave inverter capable of handling high continuous loads and inductive surges.
• Multi-Source Hybrid Charging: To maintain battery health during extended travel, the system required three independent charging methods: 855W roof solar arrays for stationary generation, 50A DC-DC alternator charging while driving, and 230V AC mains hookup when parked at campsites.
• Advanced Smart Monitoring & Sensing: Tia needed clear visibility over battery state of charge (SoC), power draw, environmental temperatures, and fluid tank levels without installing cumbersome mechanical gauges.
• Pre-Built Self-Installation: To avoid potential wiring errors on site, the core components needed to be pre-wired, pre-programmed, and mounted on a robust backing board ready for immediate physical installation.
  

System Architecture: Bespoke Pre-Built Victron Board Build

To deliver a clean, professional finish, Callidus Trade engineered a bespoke board build based on their KIT37 motorhome power bundle. The board was constructed using high-grade 15mm plywood coated with a durable white protective finish, precision-cut to match the specific arch contours of the 2021 LWB Sprinter. All major control units, busbars, fuse holders, and isolation switches were pre-mounted, wired, and bench-tested in Callidus’s Devon workshop prior to dispatch.

The complete electrical architecture incorporates industry-leading Victron Energy equipment:

• Victron MultiPlus-II 12V 3000VA Inverter Charger: The central power unit supplying 3000VA (2400W) continuous pure sine wave AC output and an integrated 120A battery charger. It powers 230V appliances cleanly while managing power pass-through when connected to mains shore power.
• 855W Monocrystalline Solar Array & SmartSolar MPPT 100/30: Three 285W 56-cell monocrystalline solar modules mounted to the vehicle roof capture up to 1.2 kWh of solar energy daily. The SmartSolar MPPT controller optimises high-efficiency DC harvesting and features built-in Bluetooth monitoring via the VictronConnect app.
• Victron Orion XS 50A DC-DC Battery Charger: An ultra-efficient 50A (700W) battery-to-battery charger that recharges the leisure battery bank from the Sprinter’s starter battery while driving, protecting the vehicle alternator with smart adaptive charging.
• Victron Smart LiFePO4 Lithium Batteries & VE.Bus BMS NG: High-density Victron Smart Lithium storage managed by the VE.Bus BMS NG (BMS30). This configuration protects battery cells against over-discharge, over-voltage, and temperature extremes while delivering maximum energy density.
• Victron Cerbo GX MK2 & GX Touch 50 Display: The central communication hub paired with a 5-inch touchscreen. It presents real-time power flow, battery state of charge, solar yield, and shore power status at a glance.
• Advanced Environmental & Tank Sensing: Includes a RuuviTag Pro rugged wireless Bluetooth sensor for precise indoor/outdoor temperature tracking, alongside two Gobius C basic stepless sensors that measure fresh and waste water levels externally through tank walls.
• Fawo Magnetic Mains Inlet & Protection: A flush white magnetic mains inlet provides clean 230V shore power connection, wired through a Victron Lynx Distributor 1000A busbar with MEGA fuses and a 5-module RCBO consumer enclosure for total circuit safety.
  

Installation, Benefits & Off-Grid Performance

By opting for a Callidus pre-built power board, the installation process inside the 2021 LWB Mercedes Sprinter is dramatically simplified. Rather than spending days mounting individual components, routing internal cabling, and troubleshooting programming settings, the pre-assembled board was securely mounted directly over the near-side wheel arch. With pre-drilled mounting holes and pre-terminated connection points, integrating the solar array, battery bank, and AC consumer unit required minimal installation time.

Key practical benefits delivered by this power configuration include:

• Plug-and-Play Installation: Pre-mounting components on a custom-shaped 15mm ply backing board eliminated complex on-site wiring, ensuring professional component spacing and robust cable management.
• Year-Round Off-Grid Power: Combining an 855W roof solar array with a 50A Orion XS DC-DC alternator charger ensures continuous energy replenishment whether parked in sunny conditions or driving between locations.
• Household AC Comfort: The Victron MultiPlus-II 3kVA inverter provides true sine wave AC power, allowing high-draw domestic appliances to operate smoothly without overloading system circuits.
• Complete System Transparency: The Cerbo GX MK2 and Touch 50 screen give instant visibility over power consumption, battery SoC, and fluid tank levels, allowing easy monitoring on the road.
• Compact Wheel Arch Fitment: Utilizing the unformed space around the Sprinter’s N/S wheel arch maximized usable interior living area for cabinetry, seating, and kitchen facilities.
  

“Providing a bespoke board build tailored to the exact wheel arch dimensions of a Mercedes Sprinter allowed us to deliver a complete off-grid power solution that is simple to install and exceptionally reliable. By integrating Victron’s 3kVA inverter charger, 855W of solar generation, and smart DC-DC charging, the KIT37 system ensures DIY van builders can enjoy complete power independence on the road with total confidence.”

— Callidus Trade Technical Team

About Callidus Trade Ltd

Callidus Trade Ltd are official UK distributors of Victron Energy and Pytes Energy, operating from Devon. Specialising in off-grid solar and battery power systems for campervan conversions, commercial mobile fleets, and residential energy storage, Callidus provides expert design, custom board assembly, and dedicated technical support. With over 30,000 products supplied and over 6,000 satisfied customers across the UK, Callidus delivers tailored power solutions engineered for demanding off-grid environments.