HP-50G Excessive Battery Drain / Fix?

[jebem]

It was interesting to know what are the manufacturing year of the affected machines.
Perhaps this can be related to a specific production batch?
Can you post your serial numbers for comparison?

So, I took some additional readings from my two 50G machines.

This time I've used my vintage lab precision analog current meter by SIEMENS Multizet Model M819-9.1B-015 just for fun!
(For power on state readings I used the 100mA range (2.5Ohm internal resistance)

Machine 1 - New old stock, original firmware:
HP-50G s/n: CNA 90302447 (year 2009)
Version HP50-C Revision #2.08 HP 2006
Power off state: 32uA
Power on, idling, clear screen: 14.8mA

Machine 2 - well used, updated firmware one year ago after buying it:
HP-50G s/n: CNA 02109127 (year 2010)
Version HP50-C Revision #2.15 HP 2009
Power off state: 27uA
Power on, idling, clear screen: 12.8mA

These readings didn't change when:
- Having a 1GB SD card inserted or not;
- Having the battery backup installed or not;