I am using a Renewal PS1 currently. Someone discarded some rechargeable alkaline AAs which were still good. They do a good job, also work for NiCd and NiMH. Not fast charging and is mostly "dumb", which seems to work with older NiMH which are still usable, but many fast/smart chargers refuse to charge. I still find it useful.
Rechargeable alkalines popped up in the 1990's but have mostly faded away. Their limited charge life and declining capacity over it were major downsides. They could leak, although seemed less egregious than regular alkalines. NiMH basically took over.
Some older AA NiMH which don't want to charge on two other chargers, are being charged by the Renewal. It is slower, no big deal. For that alone it is worth holding on to. I don't expect to get
too many more cells though.
The six rechargeable AA alkalines I recovered have been used in an outdoor temperature sensor, in pairs. Their capacity is going down, still usable after over a month but not much longer. This sensor seems hard on alkalines, holding up a few days or week maximum.