Batteries for RC modelling
There are some new battery technologies on the market for quite some time.
I found some good information data on the site from Duralite that is really worth to study:
LI-ION on Wikipedia
Please note that for storing your LiPo batteries during wintertime you should charge them at only about 3,8V or 60% of their capacity!
Some European distributors for A123 LiFe batteries/battery packs:
There are also now some manufacturers for Life batteries who make special receiver packs with different capacities:
This packs are available in Europe by certain distributors like Lindinger.at, ...