Hi Delta1067!
It's often not realized, by the asker of a question, what an enormous can of worms is involved with even beginning to properly understand the answer.
I could simply say
mdocod said:
"no, those cells you linked to will not work in your charger, and they could explode if you try to charge them in your charger!"
but that would result in a:
Delta1067 said:
In my experience, such an answer does not relieve me of further explanation so I'll continue...
I'll do a quick summery of some issues you are facing here:
3.0V rechargeable RCR123 come in 2 general "flavors."
1. In one case, it's a 3.7V (or "3.6V," same thing) lithium cobalt cell with a diode installed to buck the effective output voltage by about 0.7V, which gets them a little closer to the 3V operating range, which is usually close enough to make them compatible with a number of devices out there that normally use CR123 cells. Some of these cells are protected, some are not, they use a variety of diodes or voltage regulating devices that have different behaviors that may require different charging techniques to be safe. Most of these cells require a charging voltage terminate around 4.4-4.5V to be charged properly. The LiCo cell hiding "behind" the diode is actually being terminated at 4.20V give or take, but there is probably enough variation form brand to brand in the way that these are made, that no one charger should be assumed to be compatible with the rest of them.
2. In the other case, it's a lithium iron phosphate chemistry cell, which is naturally about a ~3.2V cell. They require a charge termination ~3.6-3.8V depending on the charge method used.
Based on a quick search here... there are reports that suggest that ultralast has released 3V rechargeable RCR123s in BOTH varieties and the only way you would know what you have would be to do some various inspection/testing...
Bottom line is this.... if your ultralast cells are the voltage-bucked LiCo type, then your charger would cause any normal 3.7V cell to reach very unsafe charge levels on a regular basis, which could lead to an explosion. Using LiFePO4 cells in that type of charger might not cause a major explosion, but could cause the cells to "pop" open, and if that didn't happen, they would certainly not last long with so much overcharge.. If your cells are the LiFePO4 type, then your charger would be useless in topping off 3.7V cells (it wouldn't only reach about 40% charge or less),.... but if your ultralasts are LiFePO4 cells, then you could just get more cells just like it, as the charging algorithm isn't as critically important in this case (they are tolerant to abuse but have low capacity). There are a number of LiFePO4 chemistry cells on the market that are cheaper than the ultralast's and would probably perform better.
Either way, it's best that you match your cells to a charger that is specified for use with those cells, or at least tested compatible by a reputable source.
Then there is the issue of compatibility. The cells you are currently using, are designed to semi-simulate the behavior of CR123 primary cells, but 3.7V cells are much different and not all devices are compatible with them. It would be ideal to look at your situation as a whole, and come to a solution that involves the proper charger with the proper cells for a particular device, and in some cases, I seriously suggest just selling the device in favor of one that can support 3.7V cells, especially 18650 size cells.
Eric
Sometimes there's a gem in the rough over there at DX!
