obsolescence, batteries

In reply to one of my earlier posts, SDF colleague (is that a good description for somebody on the same system?) solderpunk recently wrote about battery standards and gadget obsolescence. I share those views.

But what about the advances in power density of consumer batteries, what did we gain with the Li-type batteries?

I have made a quick survey of rechargeable batteries at home: Li-ion in various phones (smart and feature), and NiMH AA and AAA batteries. (I cannot say what's in my Android tablets, because those are not easily removed from the device). I have weighted them and calculated the energy density based on what's written on them — of course this may be under optimum conditions, but assuming all manufactures exaggerate more or less the same way, it should still be somewhat comparable:

• Li-ion: 0.2, 0.2, 0.05 Wh/g (the last a very small and older item)
• NiMH: 0.06, 0.1, 0.1 Wh/g

So we could say we gained about a factor of two in weight for the same energy density — but does it really matter a lot, whether you carry 25 or 50 g of batteries for a total of let's say 200 g (typical smartphone)?

But we lost on

• safety: never heard about burnt NiMH batteries, but there are entire chapters about transport safety measures for Li batteries in IATA documents
• availability/replacement: just keep some alkaline AA and AAA, and you can replace your rechargeable ones in an emergency
• environmental protection, as solderpunk nicely pointed out: the more different batteries you need, the more waste you generate

And did I already mention obsolescence..?

.:.