Rick,
I had always believed the same thing until about a year ago, when someone pointed out some literature from Dewalt (I use their 18V batteries). At least in the case of Dewalt, they state that it is better to leave the battery on the charger in maintenance mode as opposed to removing them from the charger. They actually state that a battery will loose up to 20% of its charge in the first 24 hours off the charger, 7-10% the following day and about 1% every day after that. I was able to find that document in the FAQ's of the support section on their website. Might be worth it to make a quick trip to the manufacturers website to see what they recommend. Dewalt also offers an explanation on why power tools are different from the old cordless phones that without a doubt developed a memory if you continually charged it. http://support.dewalt.com/cgi-bin/de...i=&p_topview=1