When it comes to Alkaline batteries, I buy at least $200 worth per year, most of which come from Sam's Club. I know how long they last in my various devices, of which flameless candles amount to a good percentage. (What can I say? I decorate my home for all seasons and enjoy the ambiance year around.)
I only buy high-quality flameless candles rated for 300-500 hours of use. But over time, I have gone from 2-3 months for Member's Mark AA and 1-2 months for AAA — to under 30 days for the latest set of AAA batteries from Member's Mark.
Use of these batteries in my Christmas decorations confirms that I'm not going crazy with respect to the diminished performance of alkaline batteries over the past year or two. After Thanksgiving, I replaced all my batteries and found that in every case my battery-operated string lights or flameless candles became inoperable or extremely dim within just 2 weeks.
This issue has caught my attention pretty much since the pandemic started but it continues to become progressively worse to the point where I question whether Sam's Club, maker of the Member's Mark brand, switched suppliers. Increasingly, I buy the brand name also sold by Sam's Club but I wrongly assumed that the house brand would last through the Christmas season without issue. Wrong. I find that the Energizer Max last about as long as Member's Mark used to — but not as long as alkaline batteries offered by Sam's Club did before the pandemic.
Like everything else, quality has gone down. If I am to keep my various battery-operated items going in the coming year at the current performance level, I would easily spend double of what I did a year or two ago.
I don't know if the supplier did in fact change but I have noticed as a "power buyer" of alkaline batteries that the deterioration in performance runs across multiple brands. It's a shame one can't get what one pays for anymore. It's too bad more manufacturing does not occur in the United States where quality control and price might better correlate.