>>500103Battery is never really a good reason to bring film instead of digital.
My DSLR (D3100) gets about 300-500 shots per battery with minimal screen use, being about 3 full days of shooting while travelling. If you want that much on film, you have to bring about 12-20 rolls of film. More professional level DSLRs are supposed to get 600-900+ shots per battery.
If you want more than that, you can bring a spare battery which will get you the equivalent of another 12-20+ rolls of film. I did 20 days in Nepal with 3 batteries and no re-charging.
If you are really going to be out for a very long time, then bring a small solar charging setup, one spare battery set, and then you'll only be limited by SD storage.
Further, almost all film cameras actually require a battery to function for things like autofocus/autoexposure etc; some will not function at all without battery. IMO the only reason to go film is when using a disposable camera where you are content to trade getting only 24 shit quality photos with the peace of mind knowing that you aren't going to break a more expensive setup.
