My old iPhone 3GS has no battery installed inside it and I have a bunch of photos on it. I powered it on with the wall outlet just fine but when I plug it into my iMac it doesn’t turn on. I don’t want to get a new battery for it if there are other ways to back it up. Also it takes me to a “connect to iTunes” screen when I plug it in.
That's not a successful boot - it's the recovery mode screen.
Your data is gone. There's no need to try to salvage anything using iTunes at this point.
~Lyssa
It takes about 1 minute to boot and it takes me to a screen with “iOS 6” on it. It then takes me to a connect to iTunes screen when I unlock it. So I don’t think it’s in recovery.
I watched a video on YouTube of someone taking out a battery of a working 3GS and it takes them here too. https://m.youtube.com/watch?v=hAZjm3R6IyQ
That second screen looks a lot like the the "recovery mode" screen - though it would be an older version of course
https://support.apple.com/en-us/HT201263
Does the phone boot successfully when plugged in to the wall?
~Lyssa
Is it showing you the recovery mode screen? If so, your data is gone anyway so there's no need to make the effort to back it up.
~Lyssa
Yes. It takes about a minute and it takes me to this screen.
Backup without Battery?
