IPhone :: Battery Meter On 3GS Is Low After Booting Up But Then Adjusts?

Just wondering if anyone else notices that when they first turn on (power up) their 3GS the battery meter reads really low, like below 20% sometimes, but then after 5 seconds or so will correct and read what it actually is, i.e. 50%.I thought this may be due to jailbreaking but after restoring it still happens. It will even occur first thing in the morning after I have just fully charged my phone but the discrepancy between the initial read and the actual read seems to grow throughout the day. For instance this morning the difference was only 6% where as right now it is 22% (shows 28% then goes to 50%).

I am going to run the phone until it dies today and then try fully charging it to see if that solves it. Any other suggestions/recommendations are welcome.