Lithium-ion AA rechargables

I was with a friend at Alltel (cell phone store) and they had AA rechargabels. I can`t remember if they were Lithium for sure but I think they were. I`m I confused?

I haven't heard of them, but if you get a chance to look again, please do. If you can find out who makes / sells them also that would be great.

Brock

You're never going to see LiIon cells sold over the counter as consumer products as drop-in replacements for AA cells.
For one, the voltage is wrong (over twice 1.5 volts). Second, LiIon cells must have dedicated controller circuitry to prevent catastrophic exothermic reactions from overcharging and overDIScharging.

That was also my understanding on Li-Ion (3v per cell). What I am hoping for is a Li-Ion rechargeable 123. The voltage would be right, and my understanding is they can handle the high loading of Surefires. I know they would be quite pricey and the charger would not be cheap either. If you look at how much they have come down with the popularity in cell phones I would think it should be possible. Maybe if cameras start using them more they will become more common.

Brock

Sorry guy`s, my mistake, they were NiMH AA`s.

looked good at first ken, nimh are state-of-the-art in rechargeables from what i've been reading here. rega rding the "zones" review of quantum 2000 thats a dead ringer for sears tool light, 4aa + led battery tester. read that the quantum's "bulb" is not suitable for use with alkaline cells. does this apply to ledcorps 6volt led "dual replacement led" this setup has been working for me with energizer alkalines for a couple weeks. is there a question in this somewhere?

There are Li-Ion-rechargeables available on the market. They are manufactured by TADIRAN, an Israelian weapon manufacturer.

These cells became popular by R/C model airplane pilots because of their high current capabitlity and capacity at light weight.

They are a little bit difficult to charge, as they need a combined I/U charging you will need a special charger. Also you cant charge a battery pack but have to charge every cell on its own...

As far as I know they are made in two sizes: AA and 2/3 AA.

The 2/3 AA would be able to be fit into a surefire...

The AA have about 780 mAh capacity, the 2/3AA about 450.

Discharge currents can go up to 2.5C, which means about 2 Amps for the AA and 1.3 Amps for the 2/3AA.

If you want detailled information, I can get it for you. Just email, or reply.

Bye,

Phantomas,
Would certainly appreciate knowing goodsource for those Li-on 2/3s and AAs. Thanx!

Hi!

At the moment I just know two German companies, but I will try to find out more sources.
www.batt-mann.de (only german)
www.idnet.de/homepage/scholl/ (english also)

For the charging:

You have to control current to max. 250mA per cell, and voltage to 3,4V per cell.
Also you must not charge serial packs because then the voltage on one cell could be higher than on another. You will find detailled description on the above website.

If you have any questions, mail me or reply.

If you are looking for the "standard" rechargable Li-Ions, have a look at www.saft.alcatel.fr

Bye,

I bought 2 lithium-ion battery packs(of 2 cells ea.[Qualcomm-7.2V-1200maH] from a surplus outfit, and see a circuit board integral to the cells. I have my own homebuilt charger with infinitely variable current control-1ma.-200ma., but
only voltage choices of: 1.5,3,4.5,6,7.5,9,and 12V.
-Each individual cell is about 18.5mm x65mm long.
Has anybody out there had any experience charging these cells?

Yes, these are standard Li-Ion rechargeables like used in cellphones etc. They require also a current/voltage controlled circuit. At first you have to limit the current at, say, one fifth of the capacity. Then you have also to limit the voltage to exactly 4.1V per cell. You can also not charge the cells in seriel, but have to charge each one alone.

Two voltage regulators of 317 type would do an easy charger. I will draw a circuit and post it.

hope I could help...

Do you have any idea about that integral circuit board (with the chips on it)?
In other words, is that the voltage/current regulator?
(it straddles, and is already wired up to my cells).
p.s.-I tried those 2 links, one about micro-choppers and 2nd one would not come up).

Hi!

This circuit IS the I/U controller for the cells. Most cellphone Accupacks have them integrated, so you just have to apply a certain voltage to the outgoing pins to charge.. The above link is www.saft.alcatel.COM, sorry for that..

And tell me if you need a circuit for charging (its pretty easy to make)

Bye

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Phantomas2002:
Hi!

This circuit IS the I/U controller for the cells. Most cellphone Accupacks have them integrated, so you just have to apply a certain voltage to the outgoing pins to charge.. The above link is www.saft.alcatel.COM, sorry for that..

And tell me if you need a circuit for charging (its pretty easy to make)

Bye<HR></BLOCKQUOTE>

Thanx for that!
BTW-the voltmeter on my homebuilt shows a steady rise (over an 8 hr. period-using 85ma and using the 9V. setting on my dip switch).
p.s.-I have set the automatic cutoff circuitry at exactly 9V.
-any harm there? (voltage too high, or will the built-in circuit on the cells protect them)?

I dont know enough about the circuit in your accupack to tell you exactly, but if this is an appropriate charging electronics, you wont have to use a voltage cutoff point at 9V. Just apply the chargring voltage and watch the current, it should drop by time. The charging circuit should do the following: Limit the current to a specific value at the beginning of the charge, then limiting the voltage to 4.1V per cell later, letting the current drop when the cell gets full. You could give 9 or 10 V to the electronics in your cells and measure the voltage over one cell directly and have a look if your circuit does exactly this. Li cells are easily destroyed when given overvoltage...

Much fun!

Phantomas,
Thanks 4 your input.I calculated 14 hours x 85ma.(=1200maH batt. capacity) and found that because of the attached circuit, the voltage measured 7.6V. and the current dropped off to the cells (after approx.11hrs), to less than 20ma., proving that the circuit does indeed work, just as you said it would Thanks again.

Sounds like a working cell/charger unit. Now put it into a box and attach some white LEDS

Have fun!