I use 128 GB cards by SanDisk. Work great and less worry about running out of space.

I have a K S2 and have used several different brands of batteries and chargers. An old battery no matter who makes it will over time will not hold the same charge. It incrementally holds less and less charge. This is the nature of lithium batteries the expected life is usually 500 charge cycles. I always turn off my camera when not in use to preserve the battery but even off it will lose its charge over time. I would suspect the charger if the new batteries are not charging to full. Off all the non-Pentax batteries and chargers I have found that the Kastar brand is good value and their dual bay chargers with meters are nice and can use micro or USB C cords.

HI
I highly recommend the 3 vols by Ansel Adams. The Camera, The Negative and The Print

Its a PHD in photography

The K2 lets you set a range that it can auto-set. I have mine set 100 to 6400 and -.7 ev. Like slide film, a little underexposure gives deep colors and can be corrected if too much.
Everything from 100 to 3200 is good and 6400 is very usable.

Herb

Hi
I would have both given a CLA by a good camera tech. This will remove old and stiff lubes and have new modern lubes used. I had this done to my Pentax ME Super and Superprogram. It's with the time and cost.

Herb

Pentax K S2 and the New KF

HI
I have had good results with Kastar chargers and batteries. I like the lay-flat two-port charger and the batteries seem well-made and last without swelling. I have them for my Pentax Q, K S2, KF. Also have them for my Panasonic Zs70K.

As always some innovative ideas. This is the link to the manual to see what it has to offer.
www.reveni-labs.com/incident-meter-user-manual

HI
Being a long-time Pentax user I would be interested. I have 2 ME supers and a Super Program on the film side of my collection.

I am in Denver Colorado

Herb

I use a Platyball head. Rock-solid and does not drift.