AA rechargeable batteries

[Michael Schuch]

I have a Canon camera, S5is that uses AA batteries. I tried the typical NiMH rechargeable cells but I may get 6 pictures before having to replace them, NiMH voltages run about 1.2 - 1.25 volts in my experience. This camera really prefers no less than 1.5 volts so typical alkaline aren't that great either. I discovered Nickel Zinc batteries a few years ago. They're usually 1.8 volts straight off the charger and 1.6 volts after a few hours. They maintain 1.6 volts until they need to be recharged. It's a shame this chemistry doesn't get more attention, nickel and zinc are readily available and don't have thermal overtemp issues. The self discharge isn't bad but not as good as the low self discharge NiMH batteries I don't think. A complaint I've seen is that they're 'only' good for about 500 charge/discharge cycles. I can live with 500 cycles, still cheaper than disposable alkaline. Quality control during manufacture may be an issue as well, I've had a couple NiZn cells drop to about .87 volts which others in the same device are 1.6 volts.

I just saw on Amazon that rechargeable AA Lithium Ion batteries are now available. Might have to try some of those out. I haven't really researched them yet, wonder what the self discharge rate is.

I have never heard of Nickel Zinc batteries before. I had to Google them. It sounds like they should be cheaper than NiMH, with a higher nominal voltage but lower power density and generally less recharge cycles? May I ask how much you are paying for Nickle Zinc batteries? How long have you had them? How many times have you recharged them?

I just got a dozen Amazon basic NiMH for my set of speedlights (flashes). They are still on their first cycle but lasting a very long time.

I started with Enloop NiMH and the first couple of sets were very good. Then I got a couple sets that charged only a few times before they started loosing their power very quickly. I don't know if they were genuine or knock-offs but they were priced like genuine Enloops. I figured I would try something else so I went with the Amazon basic AA NiMH batteries. I would give Nickle Zinc a try if their recharging characteristics are good and they have a decent life? My speedlights are happy with the voltage from NiMH so I don't need higher voltage batteries if their other characteristics are less than NiMH.

[Curt Harms]

Camera flashes are one of the main uses of small NiZn batteries. They have a reputation for being better for high discharge devices. I use some in a cordless barber's clipper and they seem to last pretty well. My only negative is that a few have about 50% voltage drop after little use, one will read .87 volts while its neighbors are all at 1.6 volts. Recharge them and they seem OK. The most I've charged them is a couple dozen times so can't say with certainty how many times they can be recharged before the charge life becomes too short. I've read they should handle 500 charge cycles but I figure if they last 100 charge cycles I'm money well ahead. The only sources I'm aware of are Ebay & Amazon. A company named PowerGenix did the R&D to make small NiZn cells viable and got some patents. I don't think they're still making small cells, I think they've moved on to transportation, big UPSs and other more industrial uses.