Rcr123 question

Hey fellas I am new to rechargble batteries and I have some 3v rcr123 batteries for my new d-mini. I was wondering if it is detrimental to charge the batteries at the end of the day before I hit the sack type thing? They are not fully drained mayby have 10 minutes of runtime on them? Also how can I tell if my charger is dual channel? I have been using one cell charging them both and then using the other cell the next day. I think this is probably bad for them but I am not sure so I figured I would ask you fellas as I don't want to damage my new cells. but I do like having them both fully charged lol. I am planing to buy more cells in a week from aw so I can keep two with me and have two here charging. If ya'll can convince me to buy a better charger then I will probably do so If this one is not going to charge these cells right. It is a ultralast brand with two cells, It say's smart charger with auto shut-off and led battery indicater any ideas on how to verify if this will charge one at a time? or know to only charge the dead batterie and not overcharge the full one lol I am a newb to these rechargeble batteries thanks :candle:

Hi Mudd, I don´t know if you meant 3.6V RCR´s or if they are 3V Rcr´s, there are both. But, in any case the Li-Ion rechargeable chemistry loves to be charged frequently and there is no memory effect whatsoever. their shelf life is also lousy. that being the case, it makes perfect sense to recharge them once daily. Your batteries will run out of life because of calendar days rather than recharging cycles.

There was a link to a NASA paper about li-ion life on this site, but I can't find it at the moment.

In a nutshell, li-ions have the longest overall storage performance life when stored at 40% charge. So leaving them overnight slightly discharged should not negatively effect them.

Doesn't really matter in real life, I think. Li-ions start to lose capacity the instant they roll off the assembly line, used or not. The general consensus is that they're kaput after five years no matter what.

Hi Mudd Magnet,

We've been talking about charging mismatched cells together; consensus seems to be that there isn't a problem with this so long as you are using the correct charger for the cells and neither cell is damaged from abuse or over-discharge.

You can tell if you charger is dual channel by these two means: if charging takes twice as long with two cells rather than one, it is a single channel. Or you can unplug the charger and use an ohm meter to check continuity between the + terminals, if there is continuity, it is a single channel charger.

Cell life can be influenced by many things including what was mentioned above, also the termination voltage of your charger is critical. Some chargers will stop at 4.1v; this will give a little less capacity but you will get more charge cycles. Some chargers terminate at 4.3v which will give better performance short term but cause the battery to wear out sooner; you don't want to go over 4.3v for safety reasons.

Here's a thread for info to get you started: http://candlepowerforums.com/vb/showthread.php?t=148421

Li-ions are generally rated for 300- 500 charge cycles with less than about 20% performance loss. The claims "rechargeable over 1000 times" is mostly marketing hype.

Thanks for the help fellas I think I will along pretty good with this rechageble stuff untill something comes up lol

I have another question though Should I let them sit for awhile after running them in the light before charging and when They come off the charger? As I understand the 3.7v cells come off at 4.2+v then settle down. I know the 3v won't hurt my light fresh off the charger but Is it a good Idea to get into the habbit of letting them settle so it is in my mind when I get the 3.7v cells? if so how long is good to let them settle? Thanks for all the help fellas so far I am having good luck and I am really enjoying not having to buy new cells for the light all the time these things will definatly save me some mony too

I thought shelf life (self discharge) was pretty good, much better than nimh's

just go ahead and use them after charge and charge them after use it'll be OK.

abvidledUK, I think the shelf life deal is the other way around but I might be wrong.

LED61 said:

just go ahead and use them after charge and charge them after use it'll be OK.

abvidledUK, I think the shelf life deal is the other way around but I might be wrong.

Click to expand...

I've qualified what I said, I meant shelf life due to self discharge being better than nimh's, not shelf life to death of battery.

No - I don't think Li-Ions are kaput after 5 years. The reason is from my own experience. At least 3 years ago I tore apart an old laptop battery to get the cells out of it. This was before I even knew about CPF. I set them aside thinking sometime I'd find a use for them even though I had no idea what an 18650 was or could be used in. A couple months ago I picked up a Wolf-Eyes M90 and then another LED light and both can use the 18650 (after a bulb swap in the M90). So I charged them up - they took a full charge and totally kick butt in both lights. They are probably close to 10 years old. I WAS surprised they still worked this good - might be the exception rather than the rule but these act like new cells. I've bought new RCR2 and RCR123's that were bad after only a short while and a couple charges so go figure...

Hello Matrixshaman,

Keep in mind that the definition of "kaput" is that the battery is at less than 80% of its initial capacity.

I have some Panasonic 17500 cells that are quite old. Although they still work, the are "kaput." Initially they had 1000 mAh of capacity, and now they are down to 700 mAh.

The reason for the 80% cut off is that at that point there appears to be a change in the stability of the chemistry. When cells drop below 80% of their initial capacity, it becomes more dangerous to charge them because there can be some minor plating that takes place during charging and that can develop into soft or hard shorts during the charge.

At best, the capacity of the cells is down and they should be replaced because you are getting less runtime. At worst, the cells rapidly vent with flame during charging.

Tom

Tom, why is a freezer placement but not below -20F and at 40% charge recommended for long term storage and better shelf life of Li ions ?

Hello Alberto,

Li-Ion chemistry seems to be a little unstable at full charge, and at full discharge. Half full, or 40%, is a compromise trying to stay away from the extremes.

Cooler temperatures slow down the chemical reaction. Li-Ion cells oxidize on the inside, so the cooler temperatures also slow down the oxidation. Most people that I know, store their Li-Ion cells at 40 - 50% in a zip loc bag in the refrigerator for long term storage. When getting ready to use the cells, they leave them in the zip loc bag until the cell warms up to room temperature, then they put them on the charger.

Tom

Regarding shelf life (as charge retention) the spec on my 18650 cell states >85% at 30 days after charge. That's not all so bad.

-Markcm

Ok fellas here is another question, What would make a cell stop working? The one cell is working fine but the other would not light up my light they both came off the charger at the same time and both had around 10 minutes on them when I put them to charge the green light came on saying they were done and the one wouldnt work yet the other does lol any ideas I am probably going to exchange them tommorow but I would like to know why it is doing this thanks