Apple Macbook SERVICE BATTERY status and where is it stored
&quot;Service Battery&quot; isn't stored in a file somewhere.  It's a value that, for a lack of a better term, is &quot;calculated&quot;.  The SMC reads certain values, measures the current charge and depending on the results, you get a &quot;status.&quot;
This is why you can have a faulty battery one minute, change it out with a good and it in a few moments, it will give you an updated status of &quot;Charging&quot; or &quot;Charged.&quot; (Granted, it takes more than a &quot;minute&quot; to swap a battery, but you get the idea).
You can obtain this information with the system_profiler command:
% system_profiler SPPowerDataType | grep -i &quot;charge information&quot; -A 10