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Notes: Smart Battery Hacking 2014-08-27

I’m trying to read out information from three different laptop batteries by taking advantage of the smart battery system interface.

The batteries are:

So far, I haven’t had any success in reading out data from any of the batteries, but I have figured out the pinout of the connectors:

MacBook Pro Battery ConnectorIMG_6028

From left to right, inside the wide guide slots on either side:

  • P-
  • Temperature
  • Data (SMBus)
  • Clock (SMBus)
  • Unused
  • P+

 Acer Battery Connector

IMG_6026

From left to right, inside the wide guide slots on either side:

  • P-
  • P-
  • Data (SMBus)
  • Clock (SMBus)
  • Temperature
  • Battery Activate / Enable
  • P+
  • P+

The MacBook Pro battery packs make power available all the time, while the acer batteries require a short or low resistance connection between the P- (system ground) and the Battery Activate pin in order to “wake” the battery so it will present voltage, or receive charging current. Furthermore, the Acer packs only wake up briefly if the overall pack voltage is below ~9v or so.

I’m currently using an arduino and using this post as a starting point on how to (try) to talk to a smart battery.