3.0 V rcr123 internal voltage regulation question?

[Trailbasher]

Hi…I have been through a ton of great info and require some help.

I have the following batteries and charger which show the technical specs:
http://www.batteryjunction.com/rc390reliba.html
"Internal voltage regulators. Initial cell voltage of 3.6V switches to 3-3.2V within 12ms"

When charged the batteries are approx 4.2 V. I used them in a jetbeam III-M
for 10 minutes continuously (5 low, 5 high), with some measurable heat coming of the flashlight body. The measured voltage after was 4.06 and 4.1 V.

Not understanding the technical specs of the battery; does the voltage regulation cut down the voltage while in use only? Or at all?

Bottom line is "are these voltage readings normal?"

I will eventually go to the 18650 rechargeable set up and use the rcr123's in a single cell flashlight.

Thanks in advance for all comments.

Mike

 

[Marduke]

Yes, those voltage readings are normal. Those cells only buck the voltage while in use.

 

[Howecollc]

Yes, those voltage readings are normal. Those cells only buck the voltage while in use.

While on the subject of these batteries, I have a few questions maybe you can answer. After reading several opinions on CPF about these cells, I have a fairly low opinion of them. Are these voltage regulated Tenergy cells known to be unreliable over time? Do they really have low rate of discharge problems that prevent them from driving many moderate to high current draw lights? Are they known to have less than a 2c rate of discharge? What's your opinion of the Tenergy LiFePO4s compared to AWs? Thanks for any info you have.

 

[metlarules]

I use the Tenergy 3v cells in my Olight .They have been working fine for me.

 

[Trailbasher]

I use them in series in the jetbeam III-M and as single in the romisen rc-n3 q5.....mind you, only for a couple of months now.

Anybody used them long term?
What application?
Any trouble?

Thanks

 

[mdocod]

While on the subject of these batteries, I have a few questions maybe you can answer. After reading several opinions on CPF about these cells, I have a fairly low opinion of them. Are these voltage regulated Tenergy cells known to be unreliable over time? Do they really have low rate of discharge problems that prevent them from driving many moderate to high current draw lights? Are they known to have less than a 2c rate of discharge? What's your opinion of the Tenergy LiFePO4s compared to AWs? Thanks for any info you have.

Probably me you have heard bash them repeatedly. I haven't tested them for reliability or anything, but there are some conclusions that can be drawn, I don't need a battery in front of me to point these things out:

*The diode will consume some space, so the actual cell must be made smaller than that found in a regular RCR123 in order for the total-cell-size (with PCB and diode and raised end-cap etc) to be compliant with industry standard CR123 size.
*The diode will convert some of the energy to heat as it "bucks" the effective voltage down. Further cutting into available stored energy. The amount of heat it could make if run continuously under a 1C+ load could be significant. LiCo and heat don't get along real well.
*Most of the resellers of this product group misrepresent or fail to represent the actual cell specifications. Most importantly, the maximum discharge rate, which for most of these cells is actually ~500-1000mA. Higher discharge rates would undoubtedly not only be bad for the cell itself, but probably cause more rapid heating at the diode, which would be dangerous.
*These cells must be charged with a charger that charges to ~4.4-4.5V. If these were the only cell type you were ever going to own, then that might be okay, but as soon as more cells types are introduced, this charger becomes a disaster waiting to happen when the wrong cells are inserted, (by the owner who is simply not educated, or by someone else who thinks they are doing the right thing)... [yes, I have isolated numerous battery problems for CPF members that turned out to be user error involving one of these 4.4V chargers. had those same problems occurred with unprotected cells, several houses would be ashes today, and therefor, you will hear me and most other experienced members here continue to recommend only protected cells.]

I guess what it boils down to for me is:
These cells for most people are only going to be a stepping stone of wasted money on their way to 3.7V cells in flashlights designed to handle them. After that stepping stone is crossed, they are left with a charger that is likely to be a hazard in the curious hands of most individuals.

-Eric

 

[Turbo Guy]

Tenegy specs. may be totaly false however...

# 30201

RCR 123A 3.0V / 900 mAh

charges to 4.2V overvoltage protection at 4.3
max. discharge rate protection at 3A
regulated to 3.2 and drops to 3.0 under load.
Low voltage cut off 2.5 volts.

I have two of these on order and wil be testing them soon. I am sure others have already tested them but as I have the equipment and experience I test all of my cells / batteries myself.

 

[VidPro]

Not understanding the technical specs of the battery; does the voltage regulation cut down the voltage while in use only? Or at all?

Mike

why "trust" anything, check it, put a lightweight load on, and see for yourself with a DMM. something like a nice fat wirewound resister of at least 10ohms, or a loose high power white LED on a heat sinc you can check a claim out pretty quickly, and know for sure how the item you recieved is acting.
then plopping it into your $50-300 light afterwards can be done with you knowing what it is seeing.
same thing with a charger you will use for it, run a qucik few tests on the miliamps flowing at first, then neer the end of charge, what you learn will be more valuable then the time it takes to check it a few time when starting out with the new item.

 

[Turbo Guy]

True but my experience with R/C flyers is that the ones who ask such questions do not own a DMM, have no idea how to use one,have no idea of the load required , etc..

In the case of the Tenery specs. I listed 3amps. is a 9 watt load which is fairly high for many flashlights of the LED variety.

 

[Trailbasher]

Thanks for the idea....I will try this out if I use them in a new purchase.

 

[Howecollc]

mdocod,

Thanks for that information.

 

[mdocod]

The 3 amp limit on the PCB is way above the safe limit for the cell, which is common for modern RCR123s so that they will light up bulbs without the need for multi-"clicking."

Just because the installed PCB has a maximum limit of 3 amps does not mean that the cell can safely deliver that.