As Class B vans continue to evolve into mobile residences, commercial workspaces, and premium recreational vehicles, van upfitters face increasing pressure to deliver reliable, high‑capacity electrical systems that perform consistently across customer use cases. Solar panels and DC‑DC chargers remain common components, but for builds with higher electrical loads, they often introduce performance limitations and long recharge times, which can lead to customer dissatisfaction.
For professional upfitters designing repeatable, high‑demand van power systems, secondary alternators—particularly engineered solutions from American Power Systems, Inc. (APS)—have become a preferred foundation. Let's examine why:
Solar power in professional builds
Solar charging offers quiet operation and marketing appeal, but its limitations are well understood by experienced builders. Roof real estate competes with fans, air conditioners, and racks, while shading, seasonal sun angles, and geographic location make performance unpredictable. For customers expecting reliable power for air conditioning, cooking appliances, or extended off‑grid use, solar alone rarely meets real‑world expectations.
From an upfitter standpoint, solar works best as a supplemental energy source, not the primary charging strategy in high‑demand Class B vans.
DC‑DC charging from the OEM alternator
DC‑DC chargers allow safe integration with factory alternators and are suitable for smaller battery systems. However, their current‑limited design results in slow recharge times for larger lithium banks and minimal charging performance at idle. As electrical loads increase, DC‑DC charging often becomes a bottleneck—forcing upfitters to oversize battery banks or rely on shore power to compensate.
Secondary alternators: designed for high‑demand builds
A secondary alternator creates a fully independent charging system dedicated to the house electrical load. By separating vehicle and auxiliary power systems, upfitters can deliver significantly higher charging output without stressing OEM electronics.
For professional builders, this translates into faster recharge times, predictable performance, and fewer compromises in system design—especially in vans expected to operate energy‑intensive equipment while driving or idling.
APS does not simply supply alternators; it provides engineered DC power solutions designed for integration, durability, and repeatability. Key benefits for upfitters include:
These integrated systems reduce reliance on oversized battery banks, minimize generator requirements, and shorten customer recharge times—key factors in long‑term customer satisfaction.
Ram ProMaster
APS offers high‑output alternator upgrades and dual‑alternator kits for the Ram ProMaster platform. These systems are widely used in camper vans and vocational upfits where reliable charging at idle is essential, enabling upfitters to support larger electrical loads without compromising factory systems.
Ford Transit
For Ford Transit builds, APS provides secondary alternator systems that support higher‑voltage architectures. Higher system voltage improves efficiency and reduces current over long cable runs—an important consideration for extended‑length and high‑roof vans with large battery banks.
Mercedes‑Benz Sprinter
The Mercedes‑Benz Sprinter platform demands carefully engineered electrical integration. APS secondary alternators are commonly specified in premium and professional Class B builds where long‑duty cycles, system reliability, and compatibility with advanced vehicle electronics are critical. Plus, APS has high output alternator options that bolt right into the N62 bracket and meet criteria for weight, pulley size, alignment, and kilowatt output outlined in Section 6 of the Mercedes-Benz Body & Equipment guidelines manual.
While solar panels and DC‑DC chargers remain valuable components of a balanced system, they often fall short as standalone solutions in modern Class B vans. For upfitters delivering high‑performance, repeatable builds, APS 12-, 24- and 48-volt secondary alternator systems provide a scalable, reliable power foundation that performs consistently regardless of weather, season, or customer usage patterns.
Contact us today to find the power solution right for your Class B camper van build.
