JK BMS (RS485 Modbus)

Register map(s) for this device, each at the trust rung it earned. Addresses are 0-based as on the wire; word order and scaling are only confirmed at the hardware-verified rung.

interop-verified

Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.

point	address (0-based)	type	scale	unit
cell_vol_0	4352	U16	0.001	uΩ
cell_vol_1	4353	U16	0.001
cell_vol_2	4354	U16	0.001
cell_vol_3	4355	U16	0.001
cell_vol_4	4356	U16	0.001	uΩ
cell_vol_5	4357	U16	0.001
cell_vol_6	4358	U16	0.001
cell_vol_7	4359	U16	0.001
cell_vol_8	4360	U16	0.001	H
cell_vol_9	4361	U16	0.001
cell_vol_10	4362	U16	0.001
cell_vol_11	4363	U16	0.001
cell_vol_12	4364	U16	0.001	S
cell_vol_13	4365	U16	0.001
cell_vol_14	4366	U16	0.001
cell_vol_15	4367	U16	0.001
cell_vol_16	4368	U16	0.001
cell_vol_17	4369	U16	0.001
cell_vol_18	4370	U16	0.001
cell_vol_19	4371	U16	0.001
cell_vol_20	4372	U16	0.001
cell_vol_21	4373	U16	0.001
cell_vol_22	4374	U16	0.001
cell_vol_23	4375	U16	0.001
cell_vol_24	4376	U16	0.001	H
cell_vol_25	4377	U16	0.001
cell_vol_26	4378	U16	0.001
cell_vol_27	4379	U16	0.001
cell_vol_28	4380	U16	0.001
cell_vol_29	4381	U16	0.001
cell_vol_30	4382	U16	0.001
cell_vol_31	4383	U16	0.001
cell_vol_ave	4386	U16	0.001
cell_vol_dif_max	4387	U16	0.001
temp_mos	4421	I16	0.1
bat_vol	4424	U32BE	0.001
bat_watt	4426	U32BE	0.001
bat_current	4428	U32BE	0.001
temp_bat_1	4430	I16	0.1
temp_bat_2	4431	I16	0.1
temp_bat_3	4476	I16	0.1
temp_bat_4	4477	I16	0.1
temp_bat_5	4478	I16	0.1
alarm_flags	4608	U32BE	1	mV
balan_current	4610	I16	0.001	mV
soc_cap_remain	4612	U32BE	0.001	mV
soc_full_charge_cap	4614	U32BE	0.001	mV
soc_cycle_count	4616	U32BE	1	mV
soc_cycle_cap	4618	U32BE	0.001	mV
soh	4620	U16	1	mV
run_time	4622	U32BE	1	mV

bench facts as documented (unverified)

model register	0x1400
firmware register	0x1418

generated by gemini:gemini-3.5-flash · harvested from https://github.com/syssi/esphome-jk-bms/raw/main/docs/pb2a16s20p/BMS%20RS485%20Modbus%20V1.1.pdf (JK/Jikong); manual-faithful — the document's claims, panel risk: ELEVATED — panel is not confident; proved interop-verified on 2026-06-10 · recorded 2026-06-10

The trust ladder

Each rung states what it proved and what it did not. Gray until proven; green is earned by hardware only.

generated — A prompt produced it. Unproven — anyone can regenerate this.
structure-verified — Decode path is structurally sound (addresses, widths, finite values). Does NOT prove word order or scaling.
interop-verified — Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.
simulator-verified — Decoded correctly against a protocol emulator seeded with known-true values — catches word-order/scaling errors vs the emulator, not the physical device.
hardware-verified x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.

Have a device that isn't here? Upload its register map — generation is free, and the connector earns its rung by being proven, not claimed.

Need it proven on your own device? Hardware verification — if it doesn't verify, you don't pay.

Building a platform? License the verified library — machine-readable maps, firmware matrix, API access.