"New" Ni-Zn AA battery type!

[manuka]

Their tempting Nickel-Zinc electrochem. technology has been around for ~75 years (see www.ul.ie/~childsp/CinA/Issue46/fam_chem.html), but if my recent discovery of a pair inside a new solar white LED string is any guide,it seems AA sized "Drumm Battery" Ni-Zn rechargeables may be on the way.

Non toxic Ni-Zn have well known high power output at higher voltages, & AA versions seem well suited for the likes of fast recovery camera flash charging. See =>www.engadget.com/2008/12/16/powergenix-reveals-potent-nizn-rechargeable-aa-batteries/

Although Ni-Zn energy storage levels look nothing special, their high cell E.M.F. (>1.6V) has great appeal for projects demanding 3V+ supplies. Normal NiCd/NiMH has just 1.2V, meaning 3 AAs (~3.6V) are needed for direct PICAXE work. Ni-Zn cells could do this with just 2 AAs (~3.2V), giving weight/bulk/packaging benefits.

Of course "EMF boost" circuits abound, with el cheapo single NiCd AA solar garden lamps typical, but you can't beat having a superior E.M.F. on tap to start with. Stan

 

[BeanieBots]

Very interesting Manuka.
I've always had these marked as a "dead" technology for the simple reason that it's an old technology that has never been exploited. That usually means that there is a "gotcha" somewhere.

There are many claims about the 30% higher voltage but POWER densisty appears to be LOWER than NiMh. Many claims about them being cheaper than Pb and NiMh until you actually try to get one!

No commercially available chragers (that I can find) and no information about charging and/or consequences of over charge/discharge. Curiously, the only independantly written information I could find on charger was that they like to be charged in 2.5Hrs which doesn't bode too well for solar apps.

The only thing that "figures" about finding these cells in a "cheap" solar unit is that a Chinese company has rcently bought out a failed battery manufacturer that used to make them. Maybe they are just "using up" the stock?

Could well be a technology to keep an eye on, but IMHO they have "missed the boat". The advantage that 1.6v/cell offers has already been worked around by most portable equipment when it comes to replacing 1.5v dry cells.

None the less, an interesting find. Thanks for sharing.

 

[Dippy]

Good find Stan.

I quick search shows some significant and fairly recent advances on an old technology.
I'm sure someone will post a great pile of links, but its worth keeping an eye out for.

However, I can't get overexcited about 600mAh AA batteries... so I'll wait a bit.

 

[manuka]

BB & Dippy: Good points! If marvellous battery/super-cap. advances during the last decade are anything to go by,then we're likely to see all manner of new offerings (& lemons) catering for the netbook/electric-hybrid vehicle/solar PV era ahead. Here's some recent e-bike feedback-

I'll speak up for NiZn battery chemistry from my experience. Over the last 4 years I have owned and tested 5 electric scooters ~ once a week over a hilly 15 mile commute. The first 4 used lead acid batts and all failed in a few months either in the cold or from premature ageing due to the high depth of discharge I was putting them through. I got my final scooter, an Oxygen with NiZn Evercel batts, over 2 years ago. I have noticed no 'memory effect', no drop off and no obvious sign of significant self-discharge (as with NiMH). Power does suffer in the cold somewhat but not to the extent of lead acid batts

Mmm-I see that PICAXE friendly firm Rapid (Essex-UK) is selling a Ni-Zn AA 4 pack for £1.95, but bills them as primary cells! AFAIK Ni-Zn are inherently 2° cells, although internal design is needed to stop shorting dendrite "whiskers" when recharging. At this modest price it may be worth grabbing a pack for trials => http://www.rapidonline.com/Electrical-Power/Batteries/Nickel-Zinc/Digi-1-Nickel-zinc-batteries/66864 Anyone in Blighty got a couple of quid spare -still?

 

[Dippy]

You've been going too heavy on the Google-water Stan.
I can tell, you're telling us about dendrites.

Go and have a cuppa tea, take a deep breath and wait until 5Ah AA come out.

Hopefully the 100 quid HFC will be out by then and we can quit the idea of battery powered cars saving the planet

Primary? Don't blame the messenger.... or is GP Wrong?
http://www.gpbatteries.co.uk/products/primary/digi_1.html


Edit:
I've just noticed in the GP brochure that those comparative tests were from 2003.
If they are SO GOOD, why aren't the shops full of them?

 

[BeanieBots]

Hmm.. It does quite clearly state "NON Rechargeable".
Also, not available for a few more weeks.

And don't you just hate it when they make claims about capacity but don't actually state what the capacity is

 

[manuka]

Dippy: Google not guilty! I've an electro.chem. background, & have been sprouting dendrites since the 1960s.