gotta love 50 cal ammo cans...
there are a few field McGuyver'd approach for long term storage...
1. Ziploc packs of 24 cells, get a small bucket, lower the packs in.
Now fill the bucket with sand. :twothumbs
Verdict: tried it, on a summer day outdoors the bucket gets hotter than ambient even when covered
3. Vacuum wrap cell packs use oversize bags, if theres a venting [peaceful, which by design may occur; or violent, which theres nothing you can do] you'll know immediately and, if peaceful...you've managed to isolate the gases
Verdict: tried this until the vacuum preserver retired...not one vent proved this was a optimum approach given the cost factor.
I once had it stored on a not-so-even shelf painstakingly mounted half way the height of a single pane window...if theres an incident all I need to do is shove it hard from the front and the whole assembly will go through the window...
two accidents, two new windows not once there was a vent during storage.
~200 cells later I scrapped the homemade shelf and stored them the same way as normal people does. Its on the shelf in boxes.
sometimes paranoia makes us do really stupid things. Somethings may be plausible at the time be very idiotic in retrospect