I must be missing something. Hopefully someone will clue me in. Does everything really need to be that containerized?

At home, the original container (potentially including useful data re lot no., etc.).

In the vehicle or bags, I just use Ziplocs. They adequately contain the batteries as well as any possible leakage for my purposes). If fixing their location is important, wouldn't rubber bands do the job. This approach uses general container while minimizing bulk and weight. I haven't needed to provide extra protection. Also my kit is packed tight enough that things don't move very much.

Let me know what I'm overlooking,

John