Harriet

Harriet, our 2020 Jayco Seneca 37TS Super C, parked with Vern at Chimney Rock in western Nebraska.

Harriet is our 2020 Jayco Seneca 37TS Super C and the center of our travels for roughly half the year. She gives us the freedom to move slowly, stay longer, and spend more time in places that would be difficult to experience from a hotel or a conventional campground schedule.

Rig Overview

I usually tell people to think of a semi with an apartment on the back. Harriet is our 2020 Jayco Seneca 37TS Super C, built on a Freightliner S2RV chassis. Here’s what’s under the hood:

Engine: Cummins ISB 6.7-liter diesel
Horsepower: 360 hp
Torque: 800 lb-ft
Transmission: Allison 3000 MH automatic
Fuel capacity: 100 gallons

Length: about 39'4"
Tow vehicle: 2024 Ford F-150 STX “Vern”
Combined travel length: about 65 feet

Harriet holds 100 gallons of diesel, giving us a theoretical range of around 800 miles. At our travel pace, that can mean two or sometimes three days between fuel stops, depending on how far we drive. It’s far more distance than we’d want to cover in a single day.

Jayco Seneca 37TS floor plan with slides extended: rear king bedroom, mid-coach bathroom and shower, kitchen and dinette with sofas in the living area, and front cab with an overhead bunk. Optional furniture and refrigerator configurations are shown above. — Harriet’s 37TS floor plan, shown with the slides extended. Manufacturer illustration includes optional configurations. Floorplan: Jayco, Inc.

Harriet is large enough to be comfortable for extended travel, but still gives us the flexibility to spend months moving around the country without treating every stop like a race to the next destination.

Power & Electrical

Victron 24V electrical system
Two MultiPlus-II 24/3000/70-50 inverter/chargers configured as a 120/240V split-phase system
Four SOK 25.6V 150Ah LiFePO₄ batteries
Battery bank capacity: 15.36 kWh nominal
8 kW Onan generator with automatic generator start
Separate 12V AGM system retained for the hydraulic jacks

The electrical upgrade changed how we use Harriet. Instead of planning every stay around hookups, we can comfortably spend more time off-grid and let the system manage much of the power automatically. The generator can start when the battery bank reaches a preset level, recharge the system, and shut itself back down when the batteries reach the programmed stopping point.

Who Built the System

Harriet’s Victron electrical system was designed and installed by Mark Yamamoto of Premier DC Power. Mark built the system around the way we actually travel—giving us the ability to spend extended time off-grid without giving up the comforts of the coach.

If you’re considering a serious RV electrical or lithium upgrade, you can see more of Mark’s work at Premier DC Power.

Solar

Solar readiness
Victron SmartSolar MPPT 250/70 installed
Roof solar panels: not yet installed
Portable solar: two Renogy E.FLEX 200SE panels, 400 watts total

Harriet is already wired and equipped with the solar charge controller, but the permanent roof array is still a future upgrade. For now, we can use portable panels when we want supplemental charging without running the generator.

Internet & Connectivity

Primary internet

T-Mobile Home Internet as the everyday connection
Starlink Mini Roam available as a backup when cellular coverage is weak

Internet is one of the systems that makes extended travel practical for us. T-Mobile handles most of our day-to-day connectivity, while Starlink gives us another option when we’re farther from reliable cellular service.

We’ve written more about how we approach staying connected on the road.

Onboard Network

GL.iNet GL-MT3000 router handling the RV network and VPN
Wired and wireless local network throughout Harriet
M4 Mac mini running as a headless server
Tailscale for secure remote access
AdGuard for network-wide filtering
Local file sharing and services remain available even when internet access is limited

Harriet’s network keeps our devices and local services working together regardless of which internet connection we’re using. The router handles the internal network, while T-Mobile or Starlink provides the outside connection. Our Mac mini stays on the network as a small server for files and other local services, so much of the system still works even when internet service is poor or unavailable.

Additional Upgrades

Soft starts on both air conditioners
Additional portable power and backup capability
Front grille guard for added road protection

These upgrades help make Harriet more durable and better suited to the way we travel. The air-conditioning upgrades, backup power, and grille protection make long-distance travel and extended stays easier and more resilient.