I purchased these about 20 years ago. They provide 1.5V like normal alkalines. They're supposed to need a special charger (expensive), which I did without.
I suspect they are not as robust as nicads and NIMH. I think they require gentle handling when charging. A lower charge rate. A particular peak voltage, and no higher. Etc.
I charged them with my all-purpose charger. I did not do any comparison tests, but I believe their performance dropped as I used them a few times. I must have tossed them out when they no longer appeared to hold a charge.
I have not seen rechargeable alkalines on the market for years. Many customers might have been disappointed with them.
I am happy using Ni-MH rechargeable batteries for about 20 years and I was disappointed with Ni-Cads before that. I have never used rechargeable alkaline batteries because they were very poor.
You still see them around (alkalines) but I've only run
into far-East "off-brand" looking ones and they have
consistently disappointed, and leaked soon (even on
their own co-branded charger).
When I was just a lad, we were able to recharge
plain old carbon-zinc batteries a few times before
they spooged. This was before alkalines became
a thing.