Notes about RCR123 3.0V rechargeables

[LightBright]

I was wondering why my Tenergy "900 ma" rechargeable Li-Ions were only lasting about 30 minutes in my Fenix P1D CE on the Medium setting.

I use a variable DC supply to charge my Li-ion batteries, and I typically set it to 4.20 Volts and set some current limit. This works fine for bare Li-Ion cells.

I took apart one of the Tenergy batteries to see if maybe the voltage that at the cell itself was less than 4.20V.

Sure enough - the voltage at the cell is 0.26 Volts lower than the charging voltage.

I reset the charge voltage to 4.50 Volts, and NOW I'm getting 1hr and 10 - 20 minutes out of these batteries! It's not really running the milliamp hours that they claim, but much better than before.

 

[TJZ]

LightBright, I have the Tenergy 900mAh with the
Tenergy Charger: 4.4V 360mAh.
I'm getting 1hr 12 min on my Fenix P1D CE on medium.
Sounds like you nailed the problem and are running at 100%.
Do you have a runtime on high with these batteries?
I'm getting only 20 minutes...not very good at all.

 

[abvidledUK]

I use a variable DC supply to charge my Li-ion batteries, and I typically set it to 4.20 Volts and set some current limit. This works fine for bare Li-Ion cells.

I took apart one of the Tenergy batteries to see if maybe the voltage that at the cell itself was less than 4.20V.

That's two very dangerous things to do....

 

[AndyTiedye]

Using the Tenergy "900 mah" batteries and the 4.4V charger that comes with them,
I only get a little over 30 minutes of runtime on my XR19C,
compared to over an hour with AWs or Powerizers (even Powerizer 3.0V).

Powerizer's charger charges to 4.5V, hmmm, but I'd hate to make the batteries

 

[Schnotts]

I have the exact same batteries and charger and if I leave the batteries along for a while, they die (about 3 or 4 days of being left along). Whats up with that? This normal? If I remember right, the voltage goes to 0 V after a few days whether I use the light or not.

 

[coppertrail]

Using the Tenergy "900 mah" batteries and the 4.4V charger that comes with them,
I only get a little over 30 minutes of runtime on my XR19C,
compared to over an hour with AWs or Powerizers (even Powerizer 3.0V).

Powerizer's charger charges to 4.5V, hmmm, but I'd hate to make the batteries

This is good to know, I just started using my Powerizer 3V RCR123As in my P1D CE. Do you think the Tenergy 900 mAh cells really live up to their rated capacity?

 

[LightBright]

abvidledUK - When I recharge the cells, I keep their mah rating in mind, and limit the charge current accordingly. There are a few Li-Ion chemistries that are topped off at 4.1V, but I'm not using those. I use the cells carefully, I'm not trying to pull 20 amps out of them to see what happens. Also I've designed my own temperature and current/voltage protection circuits for the flashlights I make. I know there are IC's available to do this for me but I'm in the flashlight arena to be expand my electronics knowledge and be creative. I didn't open the Tenergy cell with a hammer and a pair of pliers. I looked at it's construction, took it apart carefully, and it was setup as I expected.

Schnotts - where are you leaving the batteries? In the charger? In a flashlight?

TZ - no I haven't tried a time test on HIGH yet, I'll have to set up a Fan and keep a close eye on it.

coppertrail - No, I definitely do not think that the Tenergy batteries are living up to their claim. I'm getting about 1.25 hrs on the Medium setting with my P1D CE. I tested the input current and voltage, it's pulling 1.54 watts out of the battery. With a time of about 1.25 hrs, that works out to around 600mah, much less than they claim. I saw that chevrofreak was getting 1.5 hrs out of the AW 3.0V batteries, a bit better.

I also checked the voltage/current on HIGH - and this is with a fresh RCR123 3.0 battery - The P1D CE is pulling 4.2 watts out of the cell. There's a voltage regulator circuit inside the Tenergy battery, and it's using about a watt out of the 4.2 total watts just to regulate the voltage to ~ 3 volts, which wastes power and causes the temp of the cell to rise quickly. With that kind of load it's not too surprising they don't last long. The mah rating takes a dive for sure in that situation.

Seems that I should try the Powerizers or the AW 3.0V batteries. It would be great if Silverfox or somebody could do some RCR123 3.0V comparisons

 

[coppertrail]

The Powerizer 3V RCR123A cells claim 600 mAh. I can say this: I've been using them in my P1D CE, and I've not noticed any problems differentiating among the different modes, it runs the same as it does with primaries. Can't say how long the run time is on medium mode, I've not run it long enough.

 

[AndyTiedye]

Do you think the Tenergy 900 mAh cells really live up to their rated capacity?

I think the Tenergy 900 mah's live up to about half of their rated capacity.