LifePower4 V2 communication protocol - Batteries

RE: LifePower4 V2 communication protocol

tlane17 — Sat, 03 May 2025 00:19:41 +0000

I send the following series of HEX characters to the battery:

40 03 00 00 00 27 0A C1

And I get the following response:

40 03 4E 15 00 FE 4C 0D 1F 0D 21 0D 20 0D 21 0D 20 0D 20 0D 20 0D 20 0D 20 0D 20 0D 1F 0D 20 0D 20 0D 21 0D 1F 0D 21 00 15 00 14 00 14 00 5A 00 32 00 64 00 5B 00 02 00 00 00 00 00 00 00 00 00 01 15 75 2A 00 14 14 14 14 00 00 00 10 03 E8 00 00 BC D5

As I stated, I have decoded the pack voltage, current, and cell voltages. I would like to know what each of the fields are, I'm especially interested in where to find the cycle count.

For example, offset 0, a single byte (40) is the pack number.

offset 3 & 4, two bytes (15 00) is the pack voltage: 53.76 volts (you have to divide by 100)

offset 5 & 6, two bytes (FE 4C) is the pack current, negative indicating discharge, -4.36 Amps.

etc.

I need to know the offset and meaning for the remaining fields in the reply message.

Thanks.

RE: LifePower4 V2 communication protocol

EG4 Eric — Fri, 02 May 2025 21:25:04 +0000

Hello @tlane17, exactly what you need help with? I’ll do my best to assist you!

LifePower4 V2 communication protocol

tlane17 — Fri, 02 May 2025 18:52:12 +0000

I have a DIY monitoring box that I've used with LifePower4 V1 batteries for a couple of years. I recently purchased two new V2 batteries, and want to monitor them as well. So far, I have been able to communicate to the V2 batteries and get a response from them, but I need to know what each field is in the response. I've been able to decipher the pack voltage, current, cell voltages, etc, but not all of the fields. I am especially interested in the cycle count field. I'm using RS485 to communicate to the batteries. Thanks.