It hasn't been a really good year battery-wise. Battery defects made the news with overheating and spontaneous combustion
. Today, Matsushita Electric Industrial Co. said
it will begin mass producing a new and improved lithium-ion battery, one that presumably will not melt your PowerBook. Good news for consumers, even at the slightly higher prices anticipated for the more advanced technology. This DFW article
does not reveal exactly how the new batteries will be changed in order to minimize the risk of spontaneous combustion, but "not bursting into flames" would be a good start.