Every cell
- Each cell voltage
- Lowest, highest and average
- Cell gap (delta)
The cell that drifts is the one that will limit your whole pack: you see it first.
Home / What JBD Monitor reads from your BMS
What JBD Monitor reads from your BMS
The data a JBD smart BMS shares, without keeping a phone next to the battery.
- Every few secondson the screen and at home
- 3 yearsof history in the free Cloud
- 0settings written to your battery
Plug & playPlug in, join your Wi-Fi, done: about a minute. No app, no tools, pre-configured for your JBD.See the 3 steps →
JBD MONITOR
78%
V52.94
A+27.4
Δ CELL9 mV
TEMP24 °C
192.168.1.57 · moniwatt.local
Live values
Everything your JBD board measures, without Bluetooth
Read from the RS485 port, refreshed every few seconds, explained in plain words.
Balancing
- Balancer on or off
- Balancing current, where the board reports it
- Cells being balanced
Know whether the balancer actually works, and when.
Pack
- Voltage
- Current
- Power
- State of charge
What the pack is doing right now, charging or discharging, and how fast.
Temperatures
- Cell probes
- Power MOSFET or board
A garage in winter or a hot loft in summer: you see it before the BMS limits the current.
Switches and protections
- Charge and discharge switches
- Protections raised by the BMS
- Alarms, explained in plain words
Understand why the battery stopped charging, without opening the app next to it.
Capacity and ageing
- Remaining and full capacity
- Cycle count
- State of health, where the BMS reports it
Follow how the pack ages, month after month.
The exact list depends on your model and its firmware. Tell us your model when you order: your box is prepared and tested for it.
Try it
Your cells, as the box shows them
Pick a situation: this is what JBD Monitor shows you about each cell of your JBD pack. Values simulated.
Lowest
Highest
Gap
Temperature
Worked out for you
Not just numbers: answers
The dashboard turns the raw values into the things you actually want to know.
Why the balancer runs, or not
In one sentence: balancing from one cell to another, waiting for the start voltage, or resting under the trigger.
The cell that drifts
The one that runs ahead at full charge and falls behind when the pack is low: usually the weakest cell.
The gap, day after day
The cell gap at the top of each charge, with its trend: stable, shrinking or growing.
Time to full or empty
At the current pace, when the pack will be full, or reach its cut-off.
Home Assistant automations
Your appliances run on the sun, by themselves
JBD Monitor tells Home Assistant when the battery fills up and when it runs low. Four simple rules, and the washing machine, the water heater and the car use your sun instead of the grid. Watch a day:
10:00
Your solar production
Your consumption
Automations
- Washing machine on the sun
- The car follows the sun
- Hot water for free
- Gentle evening heating
Logbook
- Solar production
- House and heating
- Washing machine
- Water heater
- Electric car
- Battery level
- From the grid
- Sold to the grid for little
Solar used at home0 %
Bought from the grid0
Self-sufficiency0 %
Saved on this day0vs. the same day without automation
Over a year0if 150 days look like this one
Simulation of a sunny day for a house with 5 kWp of panels, a 10 kWh battery, a car that needs 10 kWh and a water heater. The energy delivered to each appliance is the same in both scenarios; only the timing changes. Your figures depend on your system, your tariff and the weather.
Alerts
An e-mail when something needs you
Set them once in your free Cloud account, box by box. No app to keep open.
- The box goes quietNo reading for 6 hours: power cut, Wi-Fi down, unplugged cable.
- Charge below your thresholdBefore the reserve is gone, not after.
- Temperature too highA hot loft or a blocked fan, caught early.
- Alarm raisedA protection or alarm from the BMS, with its meaning.
- Cell gap too wideSet your own limit in millivolts.
JBD Monitor · just now
Battery at 18 %, below your 20 % alert
Your battery dropped below the threshold you set. It is discharging at 1.2 kW: about 1 h 40 min left at this pace.
Open the dashboard
History
Three years of curves, free
The screen shows the present. The free Cloud keeps everything else.
- Day by day, hour by hour14 days of energy at a glance, then any day in detail.
- Up to 3 yearsCompare winter and summer, this year and last.
- CSV exportEverything stored, ready for your spreadsheet.
Where to see it
Six ways to look at the same data
The screen on the boxReadable at a glance when you walk past.
The local dashboardhttp://moniwatt.local on any phone or computer at home, without internet.
The free CloudFrom anywhere in the world, with history and alerts.
Home AssistantEvery sensor created automatically, no YAML
JSON API and MQTTFor your own scripts, Grafana or anything that reads JSON.
Jeedom · Node-RED · DomoticzStep-by-step guides for each one.
What JBD Monitor will never do
- Change a setting, a limit or a switch of your battery
- Send your data anywhere unless you switch the Cloud on
- Get in the way: unplug it and everything is as before
- Ask for a subscription
JBD BMS app, Wi-Fi dongle or JBD Monitor?
What each option really gives you, in short.
| Bluetooth app | Wi-Fi dongle and maker’s cloud | JBD Monitor | |
|---|---|---|---|
| Readable from anywhere in the world | — | ✓ | ✓ |
| Keeps working without internet | ✓ | — | ✓ |
| Home Assistant sensors without ESP32 or YAML | — | — | ✓ |
| A screen next to the equipment | — | — | ✓ |
| Never changes a setting | — | — | ✓ |
In detail
JBD Monitor, value by value
Pack
- State of charge, remaining and full capacity
- Voltage, current and power, charging or discharging
- Cycle count
Cells
- Each cell voltage, with min, max and spread
- Which cells the board is balancing, on boards that report it
Protection
- Charge and discharge MOSFET on or off
- Cell and pack over-voltage and under-voltage, over-current, short-circuit and temperature protections, as reported by the BMS
Temperatures
Each NTC probe connected to the board.
One brand, many boards
JBD makes small SP boards for 4S to 24S packs and larger inverter BMS such as the UP16S series. Some have an RS485 port built in, others need JBD’s RS485 module on their communication connector. Tell us the exact reference printed on your board and your cell count when you order: we test that version before shipping.
Displays
| Where | What |
|---|---|
| Screen | Charge, voltage, current, power, status |
http://moniwatt.local | Live cells, protections, temperatures, daily chart |
| Home Assistant | Auto-created device over MQTT |
| JSON API | All values for your scripts |
| Cloud dashboard (optional, free) | History, CSV, alerts |
Keep reading
Give your JBD BMS a permanent dashboard
Order JBD Monitor, shipped on 10 November 2026 and tested on a JBD smart BMS before it leaves.
Plug & play: working in about a minute
Pre-order for €49Pre-order price · €59 from 10 Nov · ships on 10 November 2026 · free cancellation until dispatch