Sweet find on 3.v rcr123 that charge at 4.2v?

[rpaloalto]

I just wanted to share these sweet little rcr123 cells I found.
They are rechargeable cr123 3V cells by soshine. One of the better brands found on DX.
http://www.dealextreme.com/details.dx/sku.13810

Here's the kicker, they charge at 4.2volts.
So like many of us who have more 4.2V chargers the we know what to do with. We don't have to find or buy that one special 3V charger.


They are standard 4.2V cells, using a set of diodes to drop the voltage to 3.3V under load.
They come off the charger at 4.2V, but ass soon as you put a load on them it drops to 3.3v

NOTE that all the info on DX is messed up. The info for Sku. 13810 is actually found under Sku. 723. And Sku 723 has the wrong picture, should be picture of 13810. Also most of the reviews are by people who have no idea what they have.

Here is some info from a DX member.

The diodes are installed under the positive end of the battery in a side by side configuration, with the negative ends of each diode opposite from the other to allow two-way current flow (necessary to allow charging). There are two types of diodes: one is a S2M, the other a SS12. The reason for using two types is to allow more voltage to be dropped under discharge than during charge. Using my DMM's diode test function, I get 556mV drop in the discharge direction, and 197mV drop in the charge direction. These voltage drops will change somewhat at higher or lower current than whatever my DMM uses to test diodes.

not my pics

 

[Greenmechanic]

Thanks for the head-up on these.
My only concern is if the diodes fail (short), you could over V your laser.
IMHO, most products that "short-cut" a original design do not perform as well as the original type will.
Only time, and usage will tell, although.:yh:

 

[rpaloalto]

I'll keep my eye on these for problems down the line. I'm using them mostly for my o-like modules. Her 150mW modules usually have no problem with 3.7V anyway.

I like it, just because I have so many lasers and flashlights that use the 4.2v chargers.

 

[styropyro]

These are pretty cool and I wouldn't mind using them on a really expensive greenie, but I never have problems hitting my green modules with fully charged 4.2 Li Ion cells.

 

[LarryDFW]

rpaloalto;

The SS14 diode in the picture above is a Schottky diode with the lower forward voltage.

It is rated for 1 amp current.

LarryDFW