The batteries for the Stinger missile should still be fine. They use a unique type of one-shot battery technology known as a "thermal battery."
It uses a powdered eutectic lithium alloy that is formed into thin slices and stacked in a round can, with cells separated by pyrotechnic powder. All of it has a hole running down the center to allow activation by a squib charge. The battery is inert until used -- when the squib charge fires, the pyro melts the lithium alloy, allowing ion flow between the anode (lithium blend) and the cathode of the cells. It only provides power as long as the cells stay hot...for the Stinger missile, only long enough to track and hit an aircraft.
The batteries have a storage life (in some cases) of over 20 years.
I used to design these things, sat next to the guy who did the Stinger missile. I did the batteries used in the Javelin anti-tank weapon. Hope our guys knock out a few Taliban tanks with something I helped out with.
Dunno if the Stinger rocket propellants are still any good, but I'm sure the batteries will power up. Our military knows this and I'm sure they are taking appropriate countermeasures.
K