> The best battery that money can buy, for two of pretty much the most important applications (can't elaborate further, sorry) was only made from ~2012 until ~2

> The best battery that money can buy, for two of pretty much the most important applications (can't elaborate further, sorry) was only made from ~2012 until ~2014. A lot of really expensive things that need that battery are now running off of old stock, which will of course eventually run out. Don't lithium ion batteries degrade over time? If that's the case, then how is this 3-5 year old stock still the best available?