I don't know how long this has been going on, but I only took notice a few days ago. When charging/sync my phone, the battery icon seems grossly incorrect. Take a look at the screenshot I've attached to this post.
The numerical battery in the corner displays 62% battery, but by the display I'd say that's about 80% or so. It's not a huge problem, but it's annoying.
I thought maybe the battery was just out of sync, so I did whole cycle and recalibrated it but nothing.
My best hunch is that there's something wrong with the BatteryBG_*.png files, but I could very well be wrong.
It's not your battery.png or whatever it is; the number is probably the true life at the moment, since it charges to 90% rather quickly, but the 90-100% takes a while causing the discrepancy, which the picture doesn't display accurately/truly, or that's my theory...
Someone feel free to correct me if that isn't right.
Hmmm. So I was toying around with my sister's iPod Touch. Beforehand everything seemed to be in order.
Then I installed a custom battery I've been working on. That wasn't adding up properly either, so I disabled it in Winterboard.
This is where things get a bit interesting. As Winterboard went through it's respring procedure, the default battery was shown on the lock screen, with a correct status approximation (numerical battery said 47 and the battery was filled a little less than half way). But suddenly the "progress bar" jumped up and is out of sync now as well.
So I'm wondering if maybe my custom battery corrupted something somehow. I didn't do anything out of the ordinary; just made the appropriate png files and loaded them into the proper directory. I've themed the rest of the interface without any problems, or is there some kind of extra step involved that I didn't know about?
Of course, that all may be a coincidence. But considering the only variable between it working and not was my custom battery that's the only lead I have at the moment.
I really hope somebody else can shine some light on this issue.