The eos on that 1802 was 2018. They stopped selling batteries for it a year before it stopped being supported. They claimed in that bulletin it was because of the shipping restrictions on batteries (which I believe!) too, so that might have had something to do with the series of decisions that led to soldered in batteries.
I didn’t even think of shipping restrictions making it prohibitively expensive to ship replacement batteries. That’s a good one.
Since you’re the op, how do you handle soldered in batteries? As you might expect from my replies, I just unsolder em (with a bench supply tacked in to keep power going to the circuit) and put in a replacement. Usually I don’t even put in battery holders, just another soldered in cell of the same type.