Configure your JK-BMS over Bluetooth, right in the browser
Connect to your JK-BMS from the browser, adjust the settings with presets and checks, and write them back. Every value is read back from the BMS to confirm it.
Works in Chrome and Edge on Windows, macOS, ChromeOS and Android. Firefox, Safari and iPhone have no Bluetooth in the browser: use a .jkcfg file there.
No Bluetooth? Work with a .jkcfg file
Export the settings in the JK BMS app, open the file here, edit it and import the result back. Handy in Firefox, Safari or on an iPhone, for backups and for preparing a second pack.
How it works
- 1
Connect
Close the JK app, press Connect BMS and pick your BMS. The editor reads every setting and checks which ones your model has.
- 2
Edit
Change values or apply a preset for LiFePO4, NMC or LTO. Each setting is explained and checked against the settings it depends on.
- 3
Write and verify
The editor writes one setting at a time in an order the firmware accepts and reads the BMS back after every step.
Direct and verified
No export and import: settings go straight to the BMS in a safe order, and anything the firmware refuses is named, not silently lost.
Chemistry-aware
Recommended ranges for LiFePO4, NMC and LTO with sources and best practices for every parameter.
Private
Everything runs in your browser. Settings read from the BMS and files you open are never uploaded, and there is no account. Usage is counted with Google Analytics, which sets cookies only with your consent.
What is JK Preset Studio?
JK Preset Studio is a free browser tool for JK-BMS settings. It connects to the BMS over Bluetooth straight from Chrome or Edge, explains every setting in plain language and writes your changes back, one at a time and verified. It works with JK boards that use the JK02 protocol and firmware 19, such as the JK-PB inverter series (JK-PB2A16S20P) and B2A boards (JK-B2A8S20P).
Use it to set up a new battery bank, copy a proven configuration to packs connected in parallel, review the settings of a used battery or keep a backup before a firmware update. Presets for LiFePO4, NMC/Li-ion and LTO cells and checks between dependent values such as OVP, OVPR and RCV catch mistakes before they reach the battery.
Writing over Bluetooth avoids the usual import errors: the editor picks a write order the firmware accepts, reads the BMS back after every step and tells you which settings your model does not have. If your browser has no Web Bluetooth, the same editor opens and saves .jkcfg files from the JK app and changes only the bytes you edit.
What you can edit
- Cell protection: OVP, OVPR, UVP, UVPR and power-off voltage
- Charging: RCV and RFV voltages, absorption and float time, SOC-100% and SOC-0% voltages
- Current protection: max charge and discharge current, OCP delays, short circuit delay and precharge
- Temperature: charge and discharge OTP and UTP, MOSFET over-temperature and heating
- Balancer: start voltage, trigger voltage and max balance current
- Battery, communication and device: cell count, capacity, smart sleep, device address, CAN and RS485 protocol, device name and passwords
Frequently asked questions
Can I change JK BMS settings without the JK app?
Yes. In Chrome or Edge on a computer or an Android phone, press Connect BMS on the home page and pick your BMS. The editor reads the settings over Bluetooth, and Write to BMS sends your changes back and checks each one. Close the JK app first: the BMS accepts only one Bluetooth connection at a time.
Which browsers and phones work?
Chrome and Edge on Windows, macOS, ChromeOS and Android support Web Bluetooth. Firefox, Safari and every browser on iPhone and iPad do not. There you can still edit a .jkcfg file exported from the JK app and import it back.
Is writing over Bluetooth safe?
The editor writes only what you changed, in an order the firmware accepts, and reads the BMS back after every step. If the firmware refuses a value, writing stops and the editor shows which setting failed and what the BMS holds now. Settings your model does not have are skipped. Download a backup first and double-check every value: wrong settings can damage cells.
Which JK BMS models are supported?
JK BMS boards that speak the JK02 Bluetooth protocol with firmware 19, for example the JK-PB inverter series (JK-PB2A16S20P) and B2A boards such as JK-B2A8S20P. Not every model has every setting: right after connecting the editor checks your BMS and marks the missing ones.
What is a .jkcfg file?
It is the configuration file the JK BMS app creates when you export the settings of a JK BMS. It is 600 bytes long and contains two data frames: one with all protection and charging settings and one with device information such as the model, firmware version and communication protocols. The same two frames are what the editor reads over Bluetooth.
How do I export and import JK-BMS settings?
In the JK BMS app connect to the battery, open the settings and use the export function to save a .jkcfg file. After editing it here, download the new file and use the import function in the same app to write it to the BMS. Export and import are available on firmware 19.05 and newer.
Is my data uploaded anywhere?
No. Settings read over Bluetooth and files you open stay in your browser, and there is no account. The site uses Google Analytics for usage statistics. Without your consent it only receives cookieless anonymous pings; with your consent it also uses analytics cookies to count returning visits. Setting values, file contents and serial numbers are never sent.
What are good JK-BMS settings for LiFePO4?
A common starting point for a 16S LiFePO4 pack is OVP 3.60–3.65 V, OVPR 3.40–3.45 V, UVP 2.6–2.8 V, RCV 3.45–3.55 V, RFV 3.35–3.40 V, balancing from 3.40 V with a 0.005–0.01 V trigger and charging blocked below 0–5 °C. Always check your cell datasheet; the parameter reference lists sources for every value.