The best RV monitoring setup tells you what's happening in your rig when you're not in it. Battery state at 2pm when you're hiking. Tank levels the morning before a long travel day. Temperature inside the rig when you leave a pet on a hot afternoon. This guide covers the three monitoring platforms worth knowing, what each one tracks, and how to configure alerts that actually matter.
What to Monitor
A complete monitoring setup covers four categories:
- Battery state of charge (SOC): The most important number in an off-grid RV. Low battery triggers a chain of problems — inverter shutoff, fridge warming, CPAP failure overnight. Know your SOC before you park for the night.
- Tank levels: Fresh water (how much is left), gray water (when to dump), black water (when to dump). Inaccurate factory sensors are the norm — aftermarket systems are significantly more reliable.
- Environmental: Temperature and humidity inside the rig (critical if you leave pets or temperature-sensitive equipment), propane levels, CO/smoke sensor status.
- Solar production and shore power: Is the solar array producing as expected? Is shore power actually connected and at the right voltage?
Victron Cerbo GX
The Cerbo GX is the central hub of a Victron-based power system. It aggregates data from all Victron components — SmartSolar MPPT charge controller, MultiPlus inverter/charger, SmartShunt battery monitor — and provides a unified view via the VRM (Victron Remote Management) portal.
From the VRM portal (web or mobile app), you can see real-time solar production, battery SOC, inverter load, and grid/shore power status from anywhere in the world. The portal stores historical data, lets you configure email/push alerts when SOC drops below a threshold, and supports remote control of some components.
Best for: Rigs built around Victron components. If your solar system is Victron, the Cerbo GX is the natural monitoring hub — it integrates without additional sensors and the VRM portal is genuinely good.
Limitation: Only monitors Victron components natively. Tank levels and environmental monitoring require additional sensors.
RV Whisper
RV Whisper ($200 device + $10/month cellular subscription) is a dedicated environmental monitoring device that works independently of your power system. It monitors temperature, humidity, propane levels, CO, and smoke sensor status — and sends push notifications when any threshold is crossed.
It connects via cellular (not your rig's Wi-Fi or Starlink), so it works even when your internet is off. This is critical for monitoring an unattended rig — if you've left and shut down Starlink, RV Whisper still sends alerts.
Best for: Anyone who leaves their rig unattended for extended periods, especially with pets, temperature-sensitive equipment, or in extreme weather. A standalone environmental safety system.
SeeLevel II Tank Monitor
SeeLevel II ($150–$200) replaces your factory tank monitors with a capacitive sensor system that reads actual tank levels rather than float sensors (which stick, fail, or read incorrectly). Adhesive sensor strips apply to the outside of each tank — no penetrations required.
The Garnet iSee app (Bluetooth version) connects to your phone and shows real-time tank levels with history. Far more reliable than OEM tank gauges for fresh, gray, and black water.
Best for: Anyone frustrated with inaccurate factory tank level sensors — which is nearly every full-timer within the first three months.
How to Configure Alerts
Victron VRM alerts: In the VRM portal → Alarm Settings → configure SOC low (set at 20% for warning, 15% for critical), battery temperature high, and grid lost. Enable push notifications to the VRM app on your phone.
RV Whisper alerts: In the RV Whisper app → Notifications → set temperature high (85°F if you have pets, 95°F otherwise), propane low (20% remaining), CO alert (any reading above 0 ppm). Enable immediate notification — don't use daily digest for safety alerts.
Combined workflow: Check Victron VRM each morning to review overnight battery draw and morning solar start. Check RV Whisper when leaving the rig for the day. Check SeeLevel app before travel days so you're not hunting for a dump station mid-route.
| System | What It Monitors | Remote Access | Connectivity | Cost |
|---|---|---|---|---|
| Victron Cerbo GX | Battery, solar, inverter, shore power | ✓ (VRM portal) | Rig Wi-Fi or LAN | $250 device, free VRM |
| RV Whisper | Temp, humidity, propane, CO, smoke | ✓ (push + app) | Built-in cellular | $200 device + $10/mo |
| SeeLevel II (Bluetooth) | Fresh, gray, black tank levels | Local Bluetooth only | Bluetooth to phone | $150–200 device |
Bottom Line
If your power system is Victron, the Cerbo GX is the monitoring hub — install it. Add RV Whisper if you leave the rig unattended for more than a few hours, travel with pets, or want cellular-independent environmental alerts. Replace factory tank sensors with SeeLevel II as soon as the stock sensors start lying to you — typically within the first year of full-time use. Together, these three systems give you a complete picture of your rig's state from anywhere.