The lithium battery controversy is filled with lies. I've fully researched them when I got mine.

Don't need a differnt charger cause the cold doesn't affect them. But if you do want to maintain it for whatever reason a standard charger on the lowest setting is ok. They say they loose sothing like 1 percent threw the winter.

Mine is a ballistic, they come with a block of foam that u cut to make a big ole foam shim for it to go in stock location.
I paid 136$ on ebay for 270cca 8cell.

The bad
They go under 30% (I think) they're cooked.
They do not tolerate any b.s. from your charging system,my friend and I blew one up when his gs500 put 15v-20v to it for 10min.
No lithium battery manufacturers actually honor thier warranty as far as I found.

The good
Weight - there isn't any
Power - tons
Fit everywhere- mines under my control arm
And I ran mine down far enough that the headlight didn't work, jumped it with my car and no issues whatso ever.