Keeping you battery free from dust and dirt is always better for your battery and device. Somtimes cleaning the battery contacts will also improve battery peformance as your battery may not be getting the proper connection necessary to charge, recharge, and report battery information to the laptop.
More Info:
Remove the battery, and AC power. If you have access to the battery contacts inside of the battery compartment (in some laptops it’s very accessible, others its almost impossible) try cleaning the connection terminals with rubbing alcohol and a Q-tip. Then re-install the battery after the contacts dry.