Test/Review of PowerGenix AA NiZn 2500mWh (Green)

PowerGenix AA NiZn 2500mWh (Green)



Official specifications:

  • Typical capacity: 1500mAh
  • Minimum capacity: 1350mAh
  • Nominal voltage: 1.65V
  • Minimum discharge voltage: 1.1V at 1C or above, 1.3V below 1C.
  • Ambient charge temperature: 0°C - 40°C
  • Ambient discharge temperature: 0°C - 50°C
  • Ambient storage temperature: less than 30 days: -20°C - 50°C, less than 90 days: -20°C - 40°C, less than 1 year: -20°C - 30°C
  • Internal impedance: <20mOhm (1000Hz)
  • Weight: About 25.0g
  • Size: 14.5(D) x 50.5(H) mm max.



Maximum temperature raise at different discharge currents: 1A:+3,0°C, 2A:+5,9°C, 3A:+8,7°C, 5A:+14,8°C

This is a chemistry that was sold as a replacement for NiMH and better suited to replace alkaline, due to the higher voltage. In practical usage the cells has a rather low lifetime, probably because they are over discharged when used as replacement for alkaline or NiMH cells.
The official capacity is not specified in mAh, but instead energy is specified in Wh, probably to hide the fact that they has less capacity than NiMH batteries.











The two cells I have tested are not very well matched and the capacity is not very high. The voltage is much higher than NiMH and alkaline, it is even higher than lithium cells.













The charging uses the same algorithm as LiIon and Pb batteries, but with another voltage, i.e. they require a special charger.



Conclusion

The cells might be useful for some special applications, but as replacement for alkaline or NiMH they are not very good. The higher voltage might damage equipment and the cells will be damaged when discharged to much.
The different in capacity between the two cell I have tested is not very good.
I do not believe the cells are useable as replacent for alkaline or NiMH.



Notes and links

How is the test done and how to read the charts
Compare to other AA/AAA batteries: Alkaline/NiMH/Lithium

Good Day HKJ,

VERY interesting & thorough review.

I was wondering about this battery technology, & You have now provided the testing, analysis & information.

Thank You Very Much,

Best Regards,

George

Thanks for all the work you do, HJK. I had hopes for the NiZn chemistry, but it’s not looking good.

Been deciding about purchasing some of these to replace nimh but after met with your test result…. nope!

Many thanks for the test!

I wonder if they suffer the same kind of problems li ion has when overly discharged for too long then attempted to recharge, if these will develop internal copper shunts on the charging medium and get very hot while charging resulting in catastrophic failure. (or does the chemistry prevent that?)

Either way…excellent review as always!

Thanks

Do you have a way of knowing the age of your cells? Im pretty sure these havent been produced in at least 2 years, so Im surprised they held any charge at all (unless they had been recharged periodically). :smiley:

Lots of complaints of these cells becoming damaged the first time they become deeply discharged. They also exhibit a short cycle life when properly cared for. I have 8 of these and use the slower version of their packaged charger, which was said to extend the cell life over the quick charger. I wasnt at all impressed with these, so mine have only been cycled a few times. I pull them out from my cell storage area twice a year to top them off. Powergenix states that the cells will self discharge and must be recharged periodically so they dont become damaged. You can dig around online, but I think these were produced as a proof-of-concept to fund a much larger project within the company or one of its parent/subsidiaries.

I have 8 cells, over 2 years old and still going. As stated put them in the ‘wrong’ device and it fries. (Done that…. :frowning: )
But, put them in the right application and they do great. Some of the old 4-AA Canon cameras handle them fine and the flash cycles better. They will NOT last as long as Eneloops though and there is a higher probability of over discharge.
They really spruce up the single AA toothbrushes :slight_smile: , as well as AA powered nose trimmers. :wink: I won’t even use those devices with AA anymore, not even lithium primaries.

I did a bit of research before I bothered to buy them so maybe I’ve been lucky at giving them appropriate care. Since the ‘average guy’ abuses WHATEVER rechargeable cell they own, a cell like this with special requirements hasn’t got a chance.

Thanks HKJ!!

Very interesting, thank you very much.

around 2Wh on 1A and a nice high voltage isnt to shabby. I thought they would be worse.
Could come in handy sometimes:

Hobbyking is currently selling NiZn.
Someone has suggested a test of those, in the request thread for batteries:

I wonder if the problem with NiZn dying is due to over-discharge, over-charge, or both?

Could they be modified by adding a protection circuit, if so?

I bought the PowerGenix charger and eight AA cells, quite a few years ago (the original PowerGenix, not from HobbyKing)
I’m now down to four viable cells, the others died fairly quickly.

One of those four is noticeably overheating when all four are charged together, typical pattern.

The charger has “0911” pressed into the case below the label, and the label says “PG-ART-003-03”
and will handle “1 to 4 AA or 1 to 2 AAA” — four slots for AA, and the middle two slots also have contacts for AAA, so that’s a physical limit at least.

I don’t know if HobbyKing’s selling the same thing or a copy.