When you're shopping for power meters energy management, the first fork in the road is scope. Do you want to see your whole home's energy use at once, or do you need to zero in on a single high-draw appliance? The Sense SM2 home energy monitor and the SONOFF LCD smart power meter switch represent those two approaches, and they sit at very different price points.
Quick verdict
If you want a whole-home view with solar generation tracking and Alexa compatibility, the Sense SM2 is the system for you - but it carries the higher price. If you just need to keep an eye on one appliance or circuit, the SONOFF gives you real-time readouts at a much lower cost and comes new.
Comparison at a glance
| Sense SM2 | SONOFF LCD Smart Power Meter | |
|---|---|---|
| Price | $199.99 | $17.99 |
| Condition | Open box, never installed | New |
| Form factor | Whole-home monitor | Single-circuit 20A switch with LCD |
| Price bar |
Where each product wins
- The Sense SM2 wins for broad visibility. It includes four CT clamps total, so you can monitor multiple points in your electrical setup from one system.
- The SONOFF wins for price and focused control. It's a low-cost way to monitor a specific appliance's power draw and keep six months of history you can export.
Product notes
Sense SM2 Home Energy Monitor
This open-box system has never been installed or connected, but both boxes have been opened and the packaging shows shelf wear, scuffs, and edge wear. Inside you get the Sense SM2 monitor, two CT150 main current sensor clamps, two additional Sense solar sensor clamps, and the original documentation and packaging. It connects over Wi-Fi and works with Amazon Alexa, making it convenient for smart-home setups. The two solar sensor clamps make it a natural fit for homes with solar panels. The clear reason to choose it is the view: with four CT clamps total, it can watch your main circuits and your solar input at the same time. The tradeoff is the open-box condition: the components are unused, but the packaging shows obvious storage wear from being moved and stored over the years. Choose it when whole-home energy insight matters more than a sealed box.
SONOFF LCD Smart Power Meter Switch
If you want a dedicated meter for one appliance, the SONOFF is a practical choice. This white switch-style monitor handles up to 20A of current and includes overload protection. Its LCD screen shows real-time power, voltage, current, and cumulative energy use directly on the device, so you don't need to open a phone app to check what's happening. It also stores six months of power usage history at hourly accuracy and lets you export the data to Excel .xlsx files. The white casing measures 98x54x31mm, so it's a compact addition to a setup. The tradeoff is the 20A ceiling: it's built for a single branch or appliance, so plan to use it on the circuit you care about. For an at-a-glance readout on one circuit, it covers the basics without a big investment.
Final choice by use case
Choose the Sense SM2 at $199.99 if you want the broader monitoring system. Choose the SONOFF at $17.99 if you want an affordable, focused meter.
