After years of lugging a charger with me both directions, I'm thinking I need a better option since it's a pain (particularly if I forget to pack the charger once).
Unfortunately, batteries and chargers are expensive. I can get my battery at $150 and the charger through the LBS at about half that.
If they were closer together, I'd go for the battery. The weight doesn't bother me and I like the idea of having enough juice for some really long rides. However, I'm wondering what others would recommend?