I've got a problem with my E525 where the battery isn't always fully charging. The issue is tempremental so is hard to diagnose but essentially when plugged in the laptop will usually charge to 100% without issue. However there have been cases where it has reached a point and given up charging. Hovering over the windows battery icon will say something along the lines of 'Plugged in, not charging'. The point at which it stops charging can be anywhere between 1 and 99% however is usually around 60-80%, however I have seen it as low as 55%.
The only way to get it to charge futher is to shut down the laptop, remove the battery and then reinsert the battery. This usually fixes the problem for a few days. The time/frequency of the issue is random too, sometimes it can happen several times a week and other times can go months with out fault.