I don't quite understand your current situation, do you own a working DSDT patch and just don't get it "translated" into a SSDT, or do you have to come up with everything yourself? If something exists already, any concrete sources of information?
Errors with _BIF (Battery Information) and _BST (Battery Status) are common, if there are fields used which are larger than a byte (8 bit). Only because all three laptops share this "common" issue, it doesn't mean you will be able to apply the same patch on all of them, at least I have a hard time of believing that.