These PowerGenix NiZn Batteries are a new type of rechargeable battery. Whilst the chemistry behind them isn’t new, until recently they had a very limited recharging life. They work at 1.65 Volts unlike the NiCad and NiMH rechargeables which produce 1.2 Volts, and alkalines which produce 1.5 Volts. They have quite a few advantages over existing batteries; they can be recharged up to 1,000 times, they’re much less toxic and much easier to recycle. There’s even a suggestion in Wikipedia that they could replace lead-acid batteries in cars. Their best feature however is their high discharge rate which means they’re very well suited to high current draw devices like digital cameras and specifically camera flash guns.
As for how much of an improvement they can offer, the flash photography blog Strobist detailed some recycle times for the high-end Nikon SB-900 flash gun. With the NiZn batteries installed it was recycling full power flashes in 1.5 seconds compared to the 4 seconds it normally takes. Pretty cool, but I expect we’ll be seeing a bit more of this as a result:
[Photo via Planet Neil]
There are a couple of gotchas to be wary of though. First, your existing chargers probably can’t charge them so you’ll need a NiZn charger. That’s probably only a temporary thing as other companies will add the higher charging voltage to their machines. The other is they have a lower mAmp hour rating (1,500 mAh) than the usual NiMH batteries (2,200 to 2,500mAh) but due to to the differences in voltages you’re comparing apples with oranges. A more useful comparison is via mWh in which the NiZn are comparable to 2,200mAh NiMH batteries, but will provide faster recycling rates. PowerGenix make 4 and 8 packs of the batteries along with a quick and normal charger with individual charging channels, all available from Amazon. AAA versions are coming soon.
PowerGenix has developed a high-energy density, high-cycle life and low-cost nickel-zinc (NiZn) battery ideal for applications that demand high discharge rate capabilities. The technology offers compelling performance advantages, most notably a 30% weight and size reduction coupled with higher power and superior low temperature discharge behavior.