How to fix a broken metal frame?

Well, it would appear difficult.

However, I have three times now snapped the battery-holding corner of the frame off. On all three occasions a carefully placed piece of masking tape has held it back on. Alternatively, use some tape to hold the battery in.

It sound a bit dodgy but it works and there's no need to pay a penny!

You could try a little super glue or jb weld to join the frame back together. I'm a little surprised this is making your battery loose, as it is primarily held in by the plastic casing...

I have repaired this metal frame successfully, but it is hard work, and I had to carefully weigh Time v Cost. Cost won, so I bought a new one from this very site. HOWEVER, when there were no time or cost constraints, and simply to DO it, I attempted the repair...

J B Weld.....ummmm NO (I cleaned the metal with MEK, let it flash to air, waited the 5 minutes for the JB to be mixed. 24 hours later, I had made a mold (impression), but I did not repair this satisfactorily.

SuperGlue (3 kinds, all aircraft/model formulations) none worked.

The only thing that actually put the metal frame back together firmly enough to support my battery (hanging) test was welding.

I used a flea market aluminum "welding" rod with the "flux" they included with the kit...

cleaned it with a stainless wire brush (theirs') and heated the weighted and positioned ends so I could

"scrub" the aluminum rod onto the break.

One big glob later. and a lot of luck,

I filed and ground (Dremel) the glob down to merely huge, and it was used in a rebuild and remains "good-to-go"

Depending on where the break is exactly... I have successfully applied aluminum foil tape (found in auto parts stores for patching mufflers!) to carefully mend cracks in case frames as well as LCD frames. Use the famous iFixit spunger to burnish it in place. That stuff if strong! Molds into any position and basically becomes hard as solder.

Just be careful not to cross any electrical connections, it IS somewhat conductive.