I bought a home battery before I knew what my home used. That's the sentence I'm embarrassed about, and it's the reason this review exists.
Two years into owning rooftop solar, I added a battery — a good one, sized by the installer — and spent the first month watching it do things I didn't understand. It drained by 9pm. It sat full on sunny afternoons while the grid exported my surplus for pennies. The installer had sized it from my annual bill, which is like sizing shoes from your annual step count. Technically data. Practically useless.
Here's the cognitive flip: the battery wasn't the problem. The ignorance was. I didn't know which circuits ate what, or when. And that's exactly the gap the Refoss Smart Energy Monitor fills — not power, but knowledge. Sixteen channels, 60 amps per channel, clamp sensors inside your electrical panel (installed by a licensed electrician — this is not a DIY afternoon, the panel is unforgiving), reporting per-circuit consumption in real time to your phone.
6.7kWh of nothing
The first week with per-circuit data rearranged my understanding of my own house. The refrigerator: 150W when running, cycling, about 1.2kWh a day — I'd guessed double. The HVAC: a 3.5kW surge at startup that I'd never seen because my old whole-home monitor smoothed it into the total. The water heater: 4.5kW, twice a day, like clockwork, and the single biggest reason my battery died by evening. The "always-on" baseline — router, smart speakers, standby loads, the garage door opener's transformer humming away — 280W, twenty-four hours a day, 6.7kWh a day doing absolutely nothing. I sat with that number for a long time. Six point seven kilowatt-hours a day of nothing. I calculated it three times.
That baseline is the real review of this product category. A single whole-home number tells you the total. Per-circuit data tells you where to swing the axe. I moved the water heater to a timer — daytime only, heated by solar — and my evening battery drain dropped by a third. One change, from one data point, worth more than a thousand dollars of extra battery capacity. The monitor paid for itself in avoided battery spending before the first month ended.
What about the Refoss specifically, versus the Emporia and Sense units that share this shelf? The Refoss's pitch is channel count: sixteen 60A circuits versus the competitors' typical eight-to-sixteen with lower per-channel ratings. For a house with a lot of 240V loads — two HVAC zones, a water heater, a dryer, an EV charger — the 60A-per-channel ceiling matters, because a 40A clamp on a 50A water heater circuit is a non-starter. The app is functional rather than beautiful. The data exports cleanly. This I can say from the spec side; the long-term app reliability — the thing that actually decides whether you still check it in year two — I haven't lived with long enough to judge, and I won't fake it.
A thermometer, not a cure
The category rant, because I have one: energy monitor marketing sells "save money" like the device itself saves anything. It doesn't. It's a thermometer. A thermometer doesn't cure the fever. What it does is convert vague guilt about your power bill into specific, actionable numbers — and then you have to act. Half the buyers I've talked to installed a monitor, looked at the data for a week, changed nothing, and now own a very accurate record of their inaction. The device is the easy part. The timer on the water heater is the hard part. Buy the monitor, but budget an afternoon for the follow-through.
Off-topic, but vivid: the electrician who installed mine had a story about every panel he'd ever opened. "This one's clean," he said about mine, which I chose to take as a compliment on my house rather than damning with faint praise. He'd seen panels with wasp nests, panels where a previous owner had labeled every breaker "misc," panels held together by optimism. There's a whole secret world inside that gray metal box, and most homeowners never look. The monitor made me look. I now know where every watt in my house goes, and it's the closest I've come to feeling like I actually own the place.
Self-criticism, directed at past me: I sized the battery from the annual bill. I could have clamped a monitor on for a month first — some electricians rent them — and bought the right size the first time. The oversizing cost me real money. The monitor would have cost a tenth of the difference. Measure first, buy second. I say this in every review now, like a penance.
The Refoss Smart Energy Monitor, after the flip: not a power device, but the thing that makes every other power device you own correctly sized and honestly evaluated. Sixteen channels of "oh, that's where it goes." Install it before the battery, not after.
Related reading: how long solar batteries last sizing a power station for home backup home battery storage systems compared
My water heater runs on sunshine now. The battery lasts the evening. The baseline is still 280W of nothing, and I'm working on that next.
