Nononono... not for willies or horizontal nudy prod. I'm talking for Lithium Ion batteries (or cells, for the purists).
When you go to buy a normal alkaline or whatever 1.5 volt or 9 volt battery at the garage, you're normally doing that because the ones in your TV remote or smoke alarm have gone flat. As a matter of course, you take the dead ones out and bin them, then get the new ones, unwrap them, and bung them into whatever it was that wasn't working. And that's it. The more prepared amongst us may have a spare pack of four in the kitchen drawer, in the bubble pack or a cardboard box.
It is vanishingly rare to hear of anyone carrying a couple of AAA or AA or even PP3 batteries around as spares. People just don't do it. Unless they're gigging musicians. They carry lots of spares. Usually in the blister pack they bought from the garage, or in bulk packs bought off the internet.
So, the fact is, most folks have little or no experience of carrying small tubes packed full of energy. They do NOT know just how energetic these things can be (yes, even alkaline ones).
Now, we all know (or should know) that the bulk of thermal runaway events with lithium ion cells happen because said cell was dropped into a pocket or back full of coins and keys. There is a short circuit, the battery/cell overheats (often amazingly quickly) and there you have it - a pocket bomb, burned leg, side, hand - wherever happens to be in the firing line.
The simple cure? A battery condom or plastic secure carrying case.
Because folks are, as I have described right at the top of this piece, not used to carrying batteries safely, they should NEVER be supplied WITHOUT the protective case or condom. Ever. And there should be a notice on each individual cell, obscuring and insulating the terminals, informing the purchaser that every cell should be in its case or condom when it is not in use or being charged. And another bloody great big card/leaflet/notice separately confirming and reinforcing that.
Who does this scheme benefit?
The vendor, for one - because he has fulfilled his obligation of safety and warning. If all that's in place and so twonk drops a bare cell into his pants pocket, he can't say he wasn't warned. So no law suit.
The inexperienced user, for two. - because it may just stop them needing skin grafts, if they act on what they've been told - after all, they don't know they needs condoms or cases.
The rest of us, for three - because it'll help stop these bloody silly going postal events, which, in turn, will take the heat off those of us who have to educate folks...
Trust me, vendors - stick you logo on a condom that costs coppers, call it advertising (which you can do - it's not on telly) and NEVER EVER SELL A BATTERY WITHOUT A FUCKING CONDOM!