JK BMS Web Gateway – WiFi monitoring for LiFePO4 batteries with JK BMS
A web dashboard and REST API running on an ESP32 in your own network: cell voltages, current, SOC, temperatures and alarms on any device at home – no cloud, no fees and no Bluetooth range of a few metres. Online access from anywhere is optional and off by default.
About the JK BMS Web Gateway project
JK BMS Web Gateway is a private project by LTSolutions from Slovakia that opens up JK BMS (Jikong) controllers for LiFePO4 solar batteries without the vendor's Bluetooth phone app or PC tool. A small ESP32 gateway reads the battery over RS485, listens to the inverter's CAN traffic and exposes everything as a JSON REST API and a web dashboard in your WiFi network.
Sound familiar?
Your inverter does not “see” the JK BMS – a different protocol, Victron, Deye or Growatt with no battery communication. The data lives only in a phone app over Bluetooth with a range of a few metres. And parallel batteries are hard to monitor. That is exactly why the gateway exists.
What you get
- Voltage, current, power, SOC, SOH, charged and discharged amp-hours and the cycle count.
- Individual cell voltages, their spread and the balancer state – you spot a weak cell before it becomes a problem.
- Cell and MOSFET temperatures, BMS alarms and protections, charge and discharge MOSFET state.
- A 24-hour history kept on the device itself and a clear report.
- Several batteries on one RS485 bus, each on its own tab.
- Viewing from a phone, tablet, PC or TV – a browser is all it takes.
- Support for JK BMS 100 A, 150 A, 200 A and 250 A, inverter and standard editions alike.
Why this gateway
- An open REST API for free – feed the battery data into your own app, chart or automation. API & docs
- A ready-made Home Assistant integration with a prepared dashboard. Home Assistant guide
- Developed and supported in Slovakia – no Chinese manual. Reviews
- Flash the firmware from your browser in minutes, no tools to install. Hardware & setup
- Our own board is coming to replace hand-wired modules. Custom board
BMS manufacturer: jkbms.com / jk-bms.com. This project is not affiliated with the manufacturer.
DEYE inverters & LiFePO4 batteries
Alongside the gateway we sell DEYE inverters and LiFePO4 batteries with JK BMS controllers directly in Slovakia – a complete solar setup, not just the software.
- Warehouse in Poprad – collect in person or get it delivered anywhere in Slovakia.
- We sell standalone LiFePO4 batteries with JK BMS as well as standalone DEYE inverters.
- We design a complete system to your needs, including monitoring and setting up battery-to-inverter communication.
- For DEYE inverters we have our own DEYE Web Gateway with the same dashboard and REST API (REST API documentation).
Sales information is at www.obchodzeu.sk or write to us via the contact form.
Gallery
Screenshots of the gateway's web dashboard (battery overview, cells, protection settings) and 3D renders of the upcoming board. We keep adding to the gallery; click an image to enlarge it.
A dedicated JK BMS Updater board is coming
We are building our own JK BMS Updater board that runs the gateway firmware without hand-wiring separate modules. The current revision:
- a compact double-sided 32 × 85 mm board for a DIN-rail enclosure,
- 7 to 60 V supply straight from the battery or a PSU, with reverse-polarity protection,
- screw terminals for both the RS485 and the CAN bus,
- a blue WiFi status LED,
- a socketed ESP32 DevKit – classic ESP32 or ESP32-S3 with more memory.
The goal is a reliable board that makes installation and maintenance easier for customers.
Unlike most off-the-shelf BMS solutions, our gateway exposes an open REST API — hook your battery data into Home Assistant, your own app, or automations, without a closed system holding you back.
Home Assistant integration
The free Home Assistant integration shows all gateway data right inside your Home Assistant: cell voltages, power, temperatures, SOC and alarms in real time, with a ready-made dashboard and colour-coded LiFePO4 cell states. It runs purely in your local network, no cloud. Installation takes a few minutes with the guide. The new JK-BMS Overview dashboard looks like the gateway itself and charts the history of power, voltage and current. DEYE inverters get their own integration with an energy-flow overview.
Free Home Assistant integration — install takes a couple of minutes.
Want to see JK BMS and DEYE in Home Assistant away from your home WiFi too? Over a VPN on your own router: Remote access guide
Contact form
Need advice on choosing a battery or inverter, or on wiring the gateway? Write to us – we usually reply within one business day.
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