As of my last knowledge update in September 2021, nickel-zinc (NiZn) rechargeable batteries typically have a nominal voltage rating of 1.6 to 1.7 volts per cell. This voltage range is somewhat lower than other common rechargeable battery chemistries like nickel-metal hydride (NiMH) or lithium-ion (Li-ion) batteries, which usually have a nominal voltage of around 1.2 volts and 3.6 to 3.7 volts per cell, respectively.
Please note that battery technologies can evolve, and there may have been developments or changes in NiZn battery specifications since my last update. I recommend checking with the manufacturer or reliable sources for the most up-to-date information on NiZn battery voltage ratings.