Over the years, I have seen people, try all kinds of tricks to get more power out of their plain old batteries. My grandmother used to keep them in the freezer all the time. Most of us just throw them away or buy rechargeable.
If you have a lot of plain batteries around that, you want to keep using a new charger called the ReZap Battery Engineer claims to be able to recharge normal batteries. The device claims to allow you to recharge normal batteries up to ten times.
The charger will work with AAAA, AAA, AA, C, D, and 9V as well as lantern batteries. It can charge four different size batteries at the same time. The Battery Engineer will launch in the US in May for $59.95.