Introduced in 1993, the Rayovac corporation marketed and sold a rechargeable battery system dubbed "Renewal". It was unique because it used a rechargeable alkaline battery which is very similar to a regular "disposable" battery and it promised to fill the gaps that the nature of "normal" rechargeable batteries left. They had a several year shelf life compared to at best a few months, fully charged they offered the same 1.5 volt power as normal alkaline compared to the 1.2 volts of Ni-Cd or Ni-MH batteries and of course were much environmentally friendly because they were basically alkaline batteries that could be recharged, no heavy metals or toxic materials requiring special disposal.
However, you had to buy a special "smart" charging unit AND fairly expensive special batteries that only lasted 20-50 charging cycles as the capacity dropped rapidly with each charge. Add in that those special batteries were notorious for leaking which often ruined both the chargers and the devices they were used in. Needless to say, the entire system was not well received met with discontinuation around 2000(?).
Still many thousands of chargers and batteries were sold in the USA. I happened to be one of those that bought both the chargers and the batteries and used them for a very long time.
Finally, however, I just retired my very last Renewal battery a few days ago. This left me with not one, but 4 Renewal branded chargers that were now utterly useless due to the lack of rechargeable Alkalines and the fact the early model chargers I owned could not be used to charge regular Ni-CD or NiMH batteries! (Yes, I do know they are still KINDA available under different names, but they suck, just like back then)
What to do? What to do...
**To get to the good stuff where the magic happens and avoid all this long winded nerdy cruft, skip ahead to step 2!