It allows a technician to directly access a battery's EEPROM to read the fuel gauge, clear error flags (PF Flags), and restore a controller to a working condition by manipulating its "SMBus" communication protocol.
There are free tools available, such as BE2Works or NLBA1 , but they often have significant limitations. Most free software cannot "unseal" modern, locked battery controllers without desoldering components. Some users mention BE2Works, but it typically starts at a licensing fee of $350 and is generally considered a dedicated alternative rather than a free replacement. ubrt-2300 universal battery repair tools
Even if the cells are good, a locked BMS will refuse to accept a charge. It allows a technician to directly access a