Lithium Batteries

Anyone tried out those lightweight Lithium ion batteries yet. They have Chinese ones on eBay for £80. Was wondering if the kilo or more weight saving is worth the dosh. I read they aren't so good in very cold conditions .. anyone used one in the winter ?

Suppose you have to ask yourself are you buying it just for the weight saving.
If you are do you think its going to make any difference to the way you ride.
Would you really notice it?

Yes fair comment ... If you need a new battery anyway then there's a better case for spending a few extra ££s. The thing is it's quite a big weight saving and the weight is quite high up. Some people are nuts enough to spend hundreds on titanium footegs/screws etc just to save about 10 grams.

Weight diffenerce would probably be most noticeable when you're trying to climb out from under the bike