3.1- Volt Lithium AA cells... direct-drive LS w/ 2 cells?

[ab]

Hi everyone,

Today I saw a set of Energizer CRV3 lithium batteries at the photo counter. (big retail price but this is all in the name of science, right?)

Anyway, the CRV3 is a 3-volt lithium battery that looks just like two lithium AA's inside a clever plastic holder (sort of like a 223 and the 123's).

Well, or so I thought. After I took these guys apart it turns out that instead of running two AA lithiums in series they are actually running two AA-lookalikes in *parallel*.

Huh? so that means the AA-lookalikes are 3 Volts?

...go get meter, separate batteries, test batteries...

Yep, within each CRV3 lithium battery is two 3-volt AA-lookalikes and they are wired up in parallel. I just went and had a look and according to Energizer's website one of the CRV3 cells is rated for 3000 mAh. That means that each 3-volt AA lookalike inside should be ~1500 mAh.

Interesting - anyone want to do a single AA Luxeon or...?

A.

 

[B@rt]

Very interesting.

I wonder if they are usable as replacements for the 3.6V Tadirans... Are they better at delivering high currents? (I was too lazy too find the specs

)
TIA,

 

[ab]

Looks like they are quite good at high currents, being designed for photo use.

I put the CRV3 datasheet here:

http://www3.telus.net/public/a6a42533/crv3.pdf

It's interesting to see that they don't tell the truth with their datasheet! They claim that the CRV3 is made up of two CR14500 in series. In fact that's not the case at all.

The cells inside CRV3 (at least the two CRV3's that I cut open today) are most certainly connected in parallel and each produce ~3.1V alone.

best regards,

A.

 

[B@rt]

Looking at the specs, they say the max continuous discharge current is 1500 mA continuous, so that would be 750mA for a single cell...

That should be enough to power a LED nicely...

Maybe you're on to something here Abohnen.

Thanks for the info.

 

[ab]

...incognito namechange...

"abohnen" becomes => "ab". Much better, less typing!

Or maybe I'll rename myself "The CPF member formerly known as abohnen".

OK, OK, silliness aside. Bart, have you considered running a set of four 1/2AA nimh's instead? This would be 4.8V. You can get them in 450 mAh (possibly more but this is the best I've seen).

Pulling 350 or 400 mA might be a bit of a stretch, but if possible it would allow a two-AA LGI or maybe a really bright LSI for example. (Not for long of course!)

A.

 

[B@rt]

Hi ab,
I haven't tried those yet, I am mostley depending on other peoples reports, as I am not in a position where I can just buy stuff and try it...

At the moment I think all my funds are directed to obtaining a McLux, but once recovered

I hope to be able to try both...

btw, the name is easier to remember.

 

[Deleted member 684]

Heh, very soon you will see that the financial reports on TV saying that the economy has risen for the better. Probably because of extra spending by a large group of people...

 

[Willmore]

These cells are being used as a 2AA replacement in a lot of digital camera designs. The cameras can take 4 AA cells or 2 of these lithium cells. So, yes, they're paralleled to provide high current capacity and to somewhat look like 2 AA cells in series. I noticed this in a high end Olympus camera I was looking at in the store the other day. I thought the size of the cells was curiously like 2 side by side AAs and the little diagram on the battery door of the camera confirmed it. It showed how to insert either kind.

Devices need to be specifically designed to handle these, but the mods aren't too difficult--some mechanical and some electrical (need to tolerate a little higher voltage than 2AAs would provide).

As far as direct drive goes, I'd never recommend that with any kind of cells. Please put something in there to limit the current.

 

[Saaby]

I want to try one in my Arc LS with the 1 AA batt. holder :evil:

 

[ab]

Saaby, email sent...

 

[highlandsun]

Should be good in a 2AA minimag as well. I'm using aluminum foil and adhesive tape to run the contacts in parallel. A bit of a hassle when you need to reload the batteries, but it's an interesting experiment.

 

[tvodrd]

I just bought a twin pack of Energizer CRV3 with 2012 date.

These are connected in series

.

Larry

 

[ab]

Hi Larry,

Let's trade a pair. I will give up two of my 3.1V for two of your 1.6V. Sound like a plan?

best regards,

A.

 

[tvodrd]

Hi ab,

Like Saaby, I se some cool possibilities for a 3V Lith AA package

. The 2 cells I seperated look to be ringers for the L91 1.5V AA, except for having black shrink tubing covers. According to the Energizer website they have different chemistries:

CRV3: LiMnO2, 3000mAh to 2V (10mA), 1500mA max continuous discharge. The pack said Made in USA.

L91: LiFeS2, 2900mAh to 1V (200mA), 2A max continuous discharge. Cells say Made in USA.

My ancient Fluke 73 says 1.790V on the CRV3 cells, and 1.785V on fresh L91s. Hopefully, somebody here can get to the bottom of this mystery.

As to a trade, I'm afraid it might break my heart to have a couple while knowing there were no more to be had anywhere.

If you really want the other pack, it's yours. I was going to strip it for what I thought were a couple L91s.

Larry

 

[ab]

Hi Larry,

Just trying to be neighbourly. I personally don't need 3V lithium AA's - I was looking to score a couple of pairs of 1.8V lithium AAs from the CRV3s actually. Nevertheless It *was* neat to find the paralleled 3.+ V cells inside and brainstorm a use for them.

I will trade them to you for a pair of L91's if you like, or for your other CRV3 pack if you like. Basically I was after some lithiums AA's to start anyway!

let me know - a PM or email, etc. are fine.

Thanks,

Aaron

 

[ab]

Hi everyone,

Sounds like most everybody has the 2 x 1.8V versions of these. So I wonder what's going on here... turns out on close inspection that my pair of CRV3 cells was "made in Japan". Here is a graphic of the back of the package:

Maybe that's the magic ticket?

best regards,

A.

 

[Abe Furburger]

Hi Guys,

Well - I got a packet, (made in Japan).

And YES ! - they are two 3V cells in pll !!!.

I put one into my Reactor LS - along with one normal lithium AA (total 4.5V) - and it now has incredible brighness - SCARY even !!!

Paid $50 Australian (about $20 US) for the two in the pack, but that gives me 4 cells to use.

Best Regards,

Abe.

 

[Deleted member 684]

This type of cell sounds really perfect for driving a 5 watt.... 2 of em ought to underdrive it just by a bit....

 

[Tree]

I wonder if the 3v AA will damage an Infinity Ultra? Or make it brighter?

 

[Tree]

To answer my own question above. No it does not seem to make it brighter (tried it earlier today). A 1.5v lithium in the Ultra is brighter than the 3v.