When I was a kid I recharged them all the time. Not just alkaline batteries but also regular non-alkaline non-rechargeable batteries. I’m talking hundreds of batteries each recharged tens of times. Eventually they stop taking a charge and you throw them away. Seems like if you let them get too hot, they are ruined and will not take a charge anymore.
Here’s a little secret for ya...
They were selling battery chargers for D cell through AA cell batteries WAY WAY BEFORE THEY INVENTED RECHARGEABLE BATTERIES.
Think about that.
I had one from radio shack. It had a slot for the little 9 volt batteries too. When have you ever heard of a rechargeable 9volt battery?
The 9 volt batteries are common today, both regular NIMH, and LSD.
I have two 9 volt alkaline rechargeable batteries. The actual voltage is something less than 9 volts. Alkaline batteries are approximately 1.25 volts per cell and alkaline batteries are approximately 1.5 volts per cell. Most chargers for rechargeable batteries are constant current chargers. Properly designed they will charge a variety of cell voltages.
Zinc-carbon batteries are rechargeable but alkalines are tricky because of the risks described in this thread.
We did too. I think my dad got his charger at a hardware store.