does baseband version affect battery life?

[anaxagoras]

Since it's the modem firmware and the 3g modem can use a lot of juice I'm assuming it has the potential to?

I"m currently on a 3gs old bootrom with baseband 04.26.08 and 4.0.1 with a custom ipsw i downloaded from a forum.

My battery life is the suck. Would it be worthwhile to consider upgrading my baseband? I do unlock but I don't rely on it, I only used it once when i went over seas last year and got a prepaid sim. Since ultrasnow will work with baseband 05.13.04 I don't see the harm in upgrading it?

As far as the process I'm using windows, i'm assuming I'd have to upgrade to 4.0.1 vanilla (no jb), downgrade to 3.0, jailbreak, then upgrade to 4.1 custom rom / jailbroken?

[dhamien]

Having a lower baseband shouldn't affect battery life. That being said, updating to 05.13.04 won't hurt you either. If you decide to update, you can make a custom firmware with pwnagetool and just include the baseband upgrade. That way you won't have to restore back and forth.