Garage door opener:battery for when electricity goes out

[Black]

Depends on what it costs. Also keep in mind the battery will need replacing, maybe as soon as two years.
Sears site currently down "for enhancements."

[AAA]

Those small batteries might need replacing, but not the larger more auto-like batteries. They should last years.

[davester]

Even if you get one of those battery gizmos, it still sounds like the guy screwed up the installation by installing the wrong springs. If you could open the door manually before, it should open manually now. The battery backup should be an add-on convenience, not a replacement for a correct installation. As someone else mentioned, you'll probably burn out your garage door opener early if the door is not properly counterbalanced.

[RAMd®d]

I know it can be done manually, and I have in the past, but the new spring does not allow for the leeway of the old type spring originally on my door. It is hard for me to manually open now.

It certainly sounds like the spring needs some additional adjustment. Has the door itself been tuned up as well?