I checked this out and it seems fine on my system. [See screenshot attached]
For some reason, I reckon the APK is being set to read-only while I import the images on your systems. Try right-clicking the Battery Mod folder and unchecking read-only (apply to sub-directories as well) and see how you go.
EDIT: If you look at files 15 and 28 in the screenshot, you will see they've been updated. Also, check my directory is the same as well.
For sure yours works as your screenshot proves that. I checked my readonly and made sure its off, tried it again, still the stock files like 15, 28, 43, etc are still not being updated.
Also just went to Command Prompt as Admin then manually called your BAT file and it ran fine as Admin thinking maybe its permissions, but it still created an APK without the original stock ones updated like 15, 28, 43, etc.
What I cant get is why when you actually manually run the 7zip command manually from the command line using the -u it still doesnt update it, acts like the command ran fine, but inside it didnt update the file at all.
Now its going to bug me to find out why on my system it dont work when on yours it does. Time to do more digging, try another system if i can and maybe then try to find out why this fails to update the stock images that exist.
Dixit
---------- Post added at 08:34 PM ---------- Previous post was at 08:17 PM ----------
Alright well I think I narrowed it down some more. I used a different Framework-res.apk and SystemUI.apk and it worked fine, one from a different rom (actually from a GB rom). Original one I kept trying was from an ICS based Rom.
So then tried a different ICS's ROM set of Framework-res.apk and SystemUI.apk. Still failed on the same 15, 28, 43, etc stock files not being over written.
So then tried a 3rd different ICS ROM using its Framework-res.apk and SystemUI.apk and what you know, it flipping WORKED! So not sure what these other two have done in the SystemUI.apk but clearly the 7zip cmd line using -u cant seem to overwrite the existing stock images and leaves them in place but just adds all the other new ones.
Dixit