I don't want to keep the battery in my hot garage. At the moment it's charging in my office, right next to me. I wanted to get a Class D fire extinguisher, but they are ridiculously expensive for what you get.

In any case, if you know where I could get a fire proof container to store it in, that would be great, thanks.

It's 12 x 3.5 x 3.5 inches.