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Shadar Al'Niende
02-04-2010, 07:44 AM
I was looking at power solutions when i stumbled across these little bad boys (http://www.engadget.com/2009/11/09/powergenix-nizn-rechargeable-aa-batteries-finally-some-cells-w/)...

That link is just a review of them but gives you a good feel for why i'm excited. They became popular just last year and have the potential to be a better Power Solution that even NiMh. I could not find a typical AA mAh rating, but it does give the ratings on some sites as follows...


Energy/weight 100 W·h/kg
Energy/size 280 W·h/L
Power/weight > 900 W/kg
Energy/consumer-price 2-3Wh/US$
Cycle durability 400-1000[1]
Nominal cell voltage 1.6 V

I'm no Electrical Engineer, but this seems like good stuff to me. Thoughts?

acerocket
02-04-2010, 10:22 AM
I don't know. It took me a while to find out what the advertised mah rating on them was to do some thinking. I found a few places were they claim these are 800 mah rated. They like to compare what they call the mwh rating. Which is just mah x voltage. I found three articles where they say these have a higher mwh rating.

"To detail more precisely the performance differences between batteries, the mAh rating—which is the product of current and time—must be enhanced to include voltage. As the product of current, time and voltage, the mWh rating delivers this much-needed measurement improvement.
Returning to the example of NiCd and NiZn cells that are each rated at 800 mAh, the mWh rating reveals the substantial performance difference between the two batteries. With an open circuit voltage of 1.2, the mWh rating of the NiCd cell would be 960 mWh (800mAh x 1.2v). Comparatively, the NiZn cell would have a much higher rating of 1280 mWh (800mAh x 1.6v).
Yes, only by employing the mWh rating does it become evident that there is a significant capacity difference between NiCd and NiZn—a difference that is masked by the limitations of the mAh rating."

So at 800 maH x 1.6V that gives a 1280 mwh versus an 800 mah nihm at 1.2V (mwh = 960). But what about a nimh at 2600 mah (Tenergy rechargeable nimh AA)? that gives a mwh of 3120. Thats a lot more than the powergenix has. It sounds great, but they are most likely using commercial cheap nimh to compare to so they look better. I'd rather stick with the nimh high mah cells unless I really needed the voltage - in which case I would go li-ion.

Count Malik
02-04-2010, 04:12 PM
:cool:cool! good find!

Rhyen Skytracker
02-04-2010, 04:19 PM
Plus it said they take 2 1/2 hours to charge. NiMH can fully charge in 45 min to 1 hour easily.

Novastar
02-06-2010, 01:07 AM
Without hardly blinking, I have to say... yeah... I'm not surprised that it's mostly a marketing + "get the word out" thing.

Also--I trust Ace's experience... and my OWN (since I've been working with Li-Ion since I began with sabers/wiring/batteries back in '05/'06 during the BOP I days)...

...if you want extra voltage
...better energy density
...lightest weight cells (Lithium is the lightest metal on the periodic table)
...a decent amount of amps to draw @ any given moment
..."flat" discharge curve
...built-in safety features with the little PCB

...Li-Ions all the way. :)

BUT!!! Ni-Mh has some SERIOUS awesome power draw though... and Li-Ion technology CANNOT (currently??) compare to it.

What I mean by "power draw" is... with Ni-Mh... you could EASILY draw 10A... probably 20A if need be. With Li-Ions... uh... that's currently impossible.

Oh, unless you disable the PCB and enjoy smoke & fire. Then... sure! Draw 20A from Li-Ions!! :) Seriously: don't.

yell0w_lantern
02-06-2010, 06:59 AM
I have a set but I haven't used my sabers much to really give you an opinion on how they compare. Plus I don't use Lithiums.

I like them because Nickel and Zinc are probably the least toxic battery components around.

Novastar
02-08-2010, 04:51 AM
I have a set but I haven't used my sabers much to really give you an opinion on how they compare. Plus I don't use Lithiums.

I like them because Nickel and Zinc are probably the least toxic battery components around.How did you deduce this if you have never even used Lithium ION cells?

http://en.wikipedia.org/wiki/Lithium-ion_battery

By the way, here is a bit on Lithium Iron Phosphate cells (LiFePO4).

http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

And as a matter of note... Lithium ION cells--don't really even have the metal "Lithium" in there. Because it's in ionic form. You can see this in the above link--it just says it in a more scientific way.

This is also another reason why I've encouraged Tim to change the listings of his cells to read: "Lithium Ion" instead of just Lithium. Lithium primary cells... unfortunately ARE using the metallic compound or whatever of Lithium.

Finally--although it can be found in the above links--Lithium Ion is a 70's (!) technology... and LiFePO4 is a 90's technology. :) This doesn't mean that Lithium Ion tech is "old school" and out-dated though... it only means that Li-Ion has seen 30 years of (successful) development. And that LiFePO4 still has places to go.

Whether or not LiFePO4 ends up being the "best in show" over Li-Ion remains to be seen. What I think is cool is... new techs and solutions are always changing/improving.