Class B RVs built on van chassis (usually a Mercedes-Benz Sprinter, Ford Transit, or Ram ProMaster) come with a manufacturer-designed electrical system. Here's what you typically get and what's worth upgrading.
What a Class B factory electrical system includes
Standard equipment across most Class B models:
- Shore power: 30A inlet (NEMA TT-30) with an automatic transfer switch
- Converter/charger: 30–50A shore power charger built into the 12V distribution center
- House battery: 100–200Ah AGM standard on most models (some premium models now include LiFePO4)
- 12V loads: Fridge, lighting, water pump, fans all wired from the house battery
- 120V loads: Outlets, microwave (if equipped) powered via shore or inverter
- Solar: Some models include 100–200W solar; others offer it as an option; some have no solar
- Generator: Some Class B models (Airstream Interstate, Winnebago Travato 59GL) have a built-in generator
Popular Class B models and their electrical specs
Winnebago Travato 59K: 200Ah AGM standard, 30A shore, 175W solar, 1,000W inverter. Upgrade path: add lithium batteries (drop-in AGM replacement), upgrade solar to 300W.
Winnebago Travato 59GL: Comes with LiFePO4 and a larger solar array from the factory. Electrical already well-optimized.
Airstream Interstate 24GT: 200Ah AGM, 30A shore, 100W solar. Common upgrade: add 200W solar, upgrade to LiFePO4.
Coachmen Beyond 22C: 100Ah AGM, 30A shore, 190W solar, 2,000W inverter. Upgrade: lithium upgrade for more usable capacity.
Thor Sequence: Built-in generator, 200Ah lithium on some trims, 30A shore.
Common Class B electrical upgrades
1. Lithium battery upgrade
Drop-in LiFePO4 replacements (same group size as factory AGM) are the most common upgrade. Benefits:
- 2× usable capacity at same or lower weight
- Faster charging (accepts full charger current vs AGM which tapers)
- No maintenance
What to change: Update the battery charger profile on the converter to LiFePO4, or replace the converter with a Victron IP22 or Blue Smart charger that has a proper LiFePO4 profile.
2. Solar expansion
Most factory Class B solar is undersized for serious boondocking. Adding 100–200W of additional panels (if roof space allows) and upgrading to an MPPT controller if the factory unit is PWM makes a meaningful difference.
3. Battery monitoring
Factory Class B RVs often have basic voltage-based gauges that are inaccurate for lithium chemistry. Adding a Victron SmartShunt + BMV-712 display gives accurate state-of-charge data.
Class B vs custom van build
| Class B RV | Custom van build | |
|---|---|---|
| Factory electrical | Included | Build it yourself |
| Upgrade cost | Moderate | Depends on starting point |
| Customization | Limited by chassis layout | Fully custom |
| Warranty | Factory warranty on electrical | None |
| Resale value | Strong | Varies |
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