SONOFF Smart Stackable Power Meter


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【Connect up to 32 SPM-4Relays】One SPM-Main can be connected 32 SPM-4Relays. Each SPM-4Relay has 4 isolated channels to help you manage devices more conveniently.
Max. 20A/Gang】Each channel can support maximum current of 20A, no fear of high power load.
【Overload Protection】Once the overload protection is enabled, it can protect your devices from burning out.
【Micro SD】SD card plays a more significant role, like export electricity consumption data quickly, store more than 20 years of historical electricity consumption and each meter relay can save 20,000 operation logs.
Power metering】Obtaining current, voltage, and power easily. You can monitor the consumption statistics of 4-Relay by checking eWeLink App on your mobile phone.
Note : The Main Unit and 4-Relay of the Stackable Power Meter need to be used together. The Main Unit is connected to at least one 4-Relay to function.
Note 2: The Main Unit capacity supported 8-32GB SDHC card. Click to buy Kingston Micro SDHC Class 10 Memory Card-32GB.

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Customer Service Guarantee

SONOFF Stackable Power Meter realizes smart management with overload protection, metadata monitoring and electricity statistics, support power-on state (the firmware of the main unit, 4-relays is upgraded to the version 1.2.0 and the eWeLink app is upgraded to 4.23.0). The SPM-Main communicates with the cloud through Ethernet or WiFi, and communicates with the SPM-4Relays through RS-485, which allows for multi-terminal and stable long-distance data transmission.

Want to know the power consumption changes of each stall? Want to realize the unified management of the whole shopping mall? By checking eWeLink App on your mobile phone, you can monitor the electricity usage without leaving home. Through the eWeLink App, you can obtain the power consumption through a touch.

Once the overload protection is enabled, you do not need to worry about electrical appliances being burned out, which helps remove potential safety hazards. In addition, you can also set the overload delay activated to avoid spurious triggering.One SPM-Main can be connected 32SPM-4Relays. Each SPM-4Relay has 4 isolated channels to help the tenant to solve the problem in electric charge sharing. Each channel can support maximum current of 20A, no fear of high power load.

Get Over 180-day of Energy Usage Data Available SD card local storage. You can insert the SD card into SPM-Main to download and check over 180 days of your energy usage history at any time of the day through HTTP API. No need to worry about missing the important information.

Package includes :
1 * Main Unit/4-Relay
1* 50cm RVVSP
1 * User Manual


Additional information


SPM-Main Input

100-240V~ 50/60Hz 50mA Max


802.11 b/g/n 2.4GHz

Micro SD card storage range


SPM-4Relay Input

100-240V~ 50/60Hz 20A/Gang 80A/Total Max

SPM-4Relay Output

100-240V~ 50/60Hz 20A/Gang 80A/Total Max



Shell material


Customer Reviews

Based on 6 reviews
Hardy Krüger

I don't know what you guys did but from the last 2 weeks the units have been working as advertised.
some features still missing like sharing but they are minor compared to the non-connection flaws experienced in first 6 months this year.
Thank you for updating the firmware or software. It's now a viable option to install as a smart DB controller.

Alberto Velez Co7398

an industrial equipment with lan connection... excellent quality and it works perfectly.

luca ferrucci

hello, to be honest I am satisfied with the build quality, but the software part is not satisfacence, in addition to being not very detailed the energy consumption part in the app, it is not supported by the ewelink dashboard, this is serious, your most expensive product has the most approximate software, it is not possible for example to see the total consumption of all 4 channels but you need to see each one separately, also the app displays the mail controller and the relay but with duplicate information, I don't know what sense all this makes .
Mine is a criticism only to explain to you what are the things that I think should be implemented immediately, otherwise it makes no sense to buy this product instead of having 4 pow 3 that have the same function, at least if there is a fault on the device it does not stop everything the plant

Hardy Krüger
No features as per other Sonoff items.

No auto power on settings.
No sharing settings
No scene settings.

Simply put this product was released prior to being finished. I expected it to have same functionality as other Sonoff products which I love.

Apart from being a bulky addition to the DB it's functionality does not deliver enough benefits to substantiate purchase and installation costs.

Good but has substantial gap

Yes, it is a nice design and appears very good. The very big gap is that, IS NOT POSSIBLE TO MEASURE THE TOTAL ENERGY. It could be even better if the MAIN PART should allow metering of the total supply and support the current for up to 100A.The main part should replace the utility single phase meter.

luca ferrucci

unfortunately this beautiful device is not supported by the ewelink web dashboard, in the app it is seen as a double device, for no reason, it is not even possible to see the total energy absorption of the 4 channels but only individually

SONOFF Smart Stackable Power Meter