Fixing a cheap battery cheaply.

Hi folks,
I have a cheap battery pack which has a busted connection on one of the serial packs. The positive fat connector has broken off of the little metal plate which I assume are welded onto the cells. Is it reasonable to solder this connection back on? Or does it really need something more robust? I'm not planning on building my own packs so buying welders and such like to do it pro-style isn't happening.

It might help us help you figure out what's safe if you attach some good clear pictures of the problem area directly to your post, using the attachments tab just below where you type your post.