I don't think the capacity should be much of an issue. I do not plan on riding in the dark more than an hour or two at a time. I will carry some spares just in case.

Hot weather? Don't really know what that is, haven't had much in MN this year.

They may have not been the batteries I would buy outright, but then they were thrown in with the charger so what the heck, kind of like getting them free.

EDIT: What about the 1000 recharges? Is that about what you can expect from rechargeables?