关于BrenTronics BT-70791CK电池SMBus v1.1通信的地址与波特率问询

First off—you can’t communicate with an SMBus device without knowing its address and baud rate; those are fundamental requirements for any I2C/SMBus transaction. The good news is that SMBus 1.1 and smart batteries follow standard conventions that almost certainly apply here. Let’s break this down:

Standard SMBus 1.1 Baud Rate #

SMBus 1.1 defines a default standard baud rate of 100kHz—this is the mandatory rate all compliant devices must support. There are optional lower (10kHz) and higher rates (though 400kHz "fast mode" was formalized in SMBus 2.0), but start with 100kHz first. It’s 99% likely this is what the BT-70791CK uses.

Standard Smart Battery SMBus Address #

For smart batteries adhering to the Smart Battery System (SBS) specification (which most SMBus-connected batteries do), the default 7-bit address is 0x0B. When translated to an 8-bit transaction address (used in most hardware drivers):

• Write address: 0x16 (calculated as 0x0B << 1 | 0)
• Read address: 0x17 (calculated as 0x0B << 1 | 1)

If this doesn’t work, you can perform an SMBus address scan: iterate through all valid 7-bit addresses (0x03 to 0x7F, skipping reserved broadcast addresses like 0x00, 0x01, 0x02) and check for an acknowledgment (ACK) response when sending a write command. Most microcontroller frameworks or SMBus tools have built-in scan functions for this.

Why the Datasheet Doesn’t List These #

It’s common for manufacturers to omit standard SMBus/SBS parameters from datasheets, assuming developers are familiar with the underlying specifications. Since the vendor confirmed this is the only available documentation, leaning on these standards is your best bet.

Quick Testing Steps #

• Set your SMBus controller to 100kHz.
• Use the 7-bit address 0x0B (or 8-bit write address 0x16) to send a basic SMBus command, like reading the battery voltage (SBS command 0x08).
• If you get a valid response, you’re good to go. If not, run an address scan to find the correct address.

内容的提问来源于stack exchange，提问作者Günkut Ağabeyoğlu