Pre-order €49.00 until 9 Nov, then €59 · ships on 10 November 2026
Pre-order · ships on 10 November 2026

Your SOK rack batteries, on your phone, even off-grid

SOK batteries often live in a shed, a cabin or a utility room far from where you are. MoniWatt for SOK brings their numbers to you over Wi-Fi.

Pre-order now — €49 See what it shows →
  • Colour screen + Wi-Fi dashboard
  • Home Assistant · JSON · Jeedom
  • Free Cloud, no subscription
MoniWatt for SOK box with screen showing battery charge, voltage and current
< 0.5 Wpowered by USB-C
0settings written to your battery
€0for the Cloud, forever
10 Novpre-orders ship

SOK 48 V server-rack batteries are a popular choice for cabins, workshops and off-grid homes, partly because they are rugged and partly because several models keep their cells warm in cold weather. What they do not do is tell you, from the kitchen, how full they are, whether the heater is on, or whether one pack is working harder than the others.

MoniWatt for SOK connects to the RS485 communication port of your batteries and reads their BMS. It shows the essentials on its own screen, the full detail on a local web page, and everything in Home Assistant. It works without internet, which matters at a cabin, and it never writes anything to the batteries.

What you get

01

Charge you can rely on

State of charge and remaining amp-hours from the battery itself, not guessed from voltage.

02

Cold-weather insight

Cell temperature and, on models with built-in heating, whether the heater is working.

03

Pack balance

See if every pack in the rack shares the load, and every cell inside each pack.

04

Works without internet

Local dashboard on your cabin Wi-Fi, no cloud needed, no subscription.

05

Alerts when it matters

Low charge, low temperature, protection tripped: an e-mail alert when your installation has internet.

06

Home Assistant ready

MQTT discovery and a JSON API for anything you run at home or at camp.

A day at the cabin, in one chart

Short winter days are when it matters most. The chart shows how much the panels gave back in the few hours of sun, how much the fridge, pump and lights took overnight, and where the charge settled at dawn. Over a week you see if the system keeps up or slowly drains.

The optional remote dashboard lets you check the cabin from home when it has an internet link, with up to three years of history.

Your data, your way

The box answers GET /api.json on your network and publishes the same values over MQTT. Home Assistant, Jeedom, Node-RED or your own script read them directly, with no cloud round-trip.

Home Assistant guide →

GET http://moniwatt.local/api.json?key=YOUR_KEY

{
  "rack": {"soc": 58, "power": -380},
  "batteries": [
    {"addr": 1, "soc": 59, "temp": 6.5, "heater": true, "delta_mv": 11},
    {"addr": 2, "soc": 57, "temp": 6.1, "heater": true, "delta_mv": 9}
  ]
}

Up and running in three steps

  1. PlugThe supplied cable goes into the RS485 / CAN port of your SOK battery; USB-C into any phone charger.
  2. ConnectJoin the box’s Wi-Fi from your phone, pick your home network and set a password. No app to install.
  3. WatchOpen the dashboard in any browser, add it to Home Assistant, and set your alerts.

Full installation guide →

Made for SOK

ModelsSOK 48 V server-rack batteries
ConnectionRS485 / CAN port, RJ45 cable included
Your existing wiringUntouched: the box reads, it never writes
NetworkYour home Wi-Fi (2.4 GHz); works without internet
IntegrationsHome Assistant (MQTT auto-discovery), JSON API, Jeedom, Node-RED, Domoticz, openHAB
CloudFree and optional: live dashboard, 3 years of history, CSV
PowerUSB-C, under 0.5 W

Another SOK model? Tell us when you order: your box is prepared and tested for it.

RJ45 communication socket and USB-C power on the MoniWatt for SOK

Small, tough enough, low power

The box takes power from any USB charger (under one watt, so it barely touches an off-grid budget) and connects to the battery with an RJ45 cable., colour screen, Wi-Fi.

It is built on the design of Pylon-Monitor, already watching Pylontech batteries in many European homes, with an RS485 / CAN board and firmware for SOK.

Designed and assembled in France

Each box is prepared and tested in France before it ships, by the team that makes Pylon-Monitor for Pylontech owners.

Questions before buying? Write to [email protected]: a person answers.

MoniWatt for SOK

€49.00

Pre-order price until 9 November 2026 · €59 afterwards

VAT not applicable (art. 293 B CGI) · shipping calculated at checkout

  • MoniWatt for SOK with colour screen and RS485 / CAN interface
  • RJ45 communication cable
  • USB-C cable
  • Free Cloud Access, no subscription
Pre-order now

Ships on 10 November 2026 · free cancellation until dispatch

Questions people ask first

Which SOK batteries are supported?

We target SOK 48 V server-rack batteries with RS485 communication ports. Tell us your model when you order and we test it before shipping.

Does it work with no internet?

Yes. Screen, local dashboard, MQTT and JSON API all work on a local network with no internet. E-mail alerts and the remote dashboard need an internet connection.

How much power does it use?

Under one watt from a USB charger, about the same as a phone charger left plugged in.

Can I read 12 V SOK batteries?

This edition targets the 48 V rack models with RS485. The small 12 V batteries mostly use Bluetooth only and are not covered.

All questions →

Know your SOK batteries from the house

Order MoniWatt for SOK today. Prepared and tested for your rack, dispatched on 10 November 2026.

Pre-order for €49Pre-order price · €59 from 10 Nov · ships on 10 November 2026 · free cancellation until dispatch