First, please update you profile to indicate the model number, not the device nickname. there are several Bolds and they are somewhat different. We need that to help you.
There are probably apps running in the background. Maybe this will help; http://www.blackberryfaq.com/index.p...m_Battery_Life
Also, if you let the battery get below 20% on a consistent/regular basis, it can damage it. That could also be part of the problem. If that is the case, or the device and battery are old, you might try a replacement OEM battery from a reputable source, not a cheap knock off.