DIYBMS v4 Missing Components

[cozwei (Sebastian Böttger)]

@stuart
The PCA9538PW/Q900,118 seems to be a combination of both, offering the following features:

• Operating power supply voltage range of 2.3 V to 5.5 V (3.0 V to 5.5 V
  for PCA9538PW/Q900)
• 5 V tolerant I/Os