In keeping with the *ahem* frugality I have already demonstrated in this thread, I have found a reasonably priced charging adapter for the Divesoft Trimix analyzer.
https://www.amazon.com/gp/product/B07HNL5D56/
Divesoft charges $40 for theirs, which just seems like highway robbery, to me. A buddy of mine did spend the big bucks for that one, so I looked at it to note the specs and measure the plug.
The Divesoft charger is 12V - 1.25A. The plug is a standard 5.5mm - 2.1mm, center positive plug.
This charger on Amazon is 12v - 2A. The attached plug is 5.5mm - 2.1mm, center positive. It comes with 2 extra plugs that the attached plug will plug into, but they are unneeded for use with the Divesoft analyzer.
I received the charger from Amazon today and verified that it works just fine with the analyzer.
$9.99 with Prime shipping. I like that much better than $40...
On a somewhat related note, I did not buy a charger sooner because the analyzer came fully charged and it allows you to power it with a 9V battery. At $40 for a charger, I figured I would just put a 9V in, as needed. I put one in immediately when I got the analyzer.
The way I expected the analyzer to work is that it would deplete the internal rechargeable battery first and then start using the 9V. That just makes sense, to me. The 9V should be a backup that is never used if you keep the unit charged. But, I did inquire with Mat at Divesoft and he told me that it works the other way around. It uses the 9V first.
My analyzer showed a full charge back when I got it at the beginning of December. Each time I used it, the charge (as displayed at bootup) would drop. Very recently, I powered it up and it came up showing fully charged. I had not charged it or replaced the 9V battery. All I can figure is that what it WAS showing me on bootup was the charge level of the 9V battery. Even though the display SAID "internal Li-Ion battery". Then, the 9V finally was dead and the unit switched to actually using the internal rechargeable battery. At which point, the display at bootup started showing that.
When the wall charger is plugged in, if you turn the unit on, the display says something like "internal battery charging". Other than that display at bootup, the analyzer gives no indication that it is charging, whether the analyzer is powered on or off. I cannot find anyway to view the battery status, other than watching the display for that 2 seconds or so during bootup.
I took the 9V battery out and threw it away. I will keep a spare 9V in the case, for just in case, but now that I have a wall charger, and considering how long the analyzer lasts from a full charge, I don't expect to ever actually use the 9V.