questions on battery specs

hi, i am still new to this whole this so i want to do some research before i start buying stuff.

ok so first off, if a torch says that it accepts 2xcr123a, 2x16340, or 1x17670, which one out of the three would be better? or are they all the same. When i say better i mean most bang for your buck vs best performance out of your torch.

Second Ive seen, lets say cr123a batteries, rate them selves at 3.0v @ 650 mah, and 3.7v @ 1000mah, and a bunch more ranging in between. My question is, does more volts mean more power? or more life? or is more mah more power? or just more life.

Welcome to CPF, itsmejaytee.

I think this would be better dealt with one thing at a time, so I've edited some slightly contentious references from the last part of your post. I'll move the thread into the batteries section, and when you have received answers to your questions, perhaps then would be the time to return to the question of which light might best suit you.

Hi there, welcome to CPF ! :welcome:

itsmejaytee said:

hi, i am still new to this whole this so i want to do some research before i start buying stuff.

ok so first off, if a torch says that it accepts 2xcr123a, 2x16340, or 1x17670, which one out of the three would be better? or are they all the same. When i say better i mean most bang for your buck vs best performance out of your torch.

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How the torch will react to the various power options will vary from torch to torch just depending on what electronics are used to regulate the LED. BTW you'll only find these types of broad sweeping power options on regulated LED flashlights.

A general rule of thumb is that lights listed as compatible with "2xcr123a, 2x16340, or 1x17670," will have the following characteristics:
1. On 2xCR123 (2 3V primary cells), the light will behave pretty normally, have good long regulated runtime with some dimming thereafter, sometimes followed by a miniscule amount of available light for several hours after the cells are almost completely depleted.
2. On 2x16340, (they are talking about a pair of 3.7V rechargeable "RCR123" cells), the light will have near perfect regulated output but with reduced runtime compared to CR123s. The regulation circuit will allow the higher voltage and simply buck the higher voltage down to the needs of the LED for the chosen output level.
3. On 1x17670, (this is a single 3.7V cell with approximately the length of a pair of CR123s, but rechargeable) The input voltage is very close to the Vf of the LED in this configuration, in this case, the regulator has little to no voltage above the LEDs voltage needs to regulate, so the regulator is *essentially* bypassed and the flashlight operates in direct-drive mode. The output dims as the battery drains. The advantage of this can be that a continuously dimming direct drive setup is the most efficient. The light will slowly get dimmer and dimmer through the run as the voltage of the cell drops, but it will run for a very long time.

Second Ive seen, lets say cr123a batteries, rate them selves at 3.0v @ 650 mah, and 3.7v @ 1000mah, and a bunch more ranging in between. My question is, does more volts mean more power? or more life? or is more mah more power? or just more life.

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Try to think of voltage as pressure, and mAH (mili amp hours) as the size of the tank that the pressure is stored in. More mAH translates to longer running time, while more voltage means more work can be done in less time.

In order to compare batteries with different voltages and capacities, just multiply the voltage and the capacity to figure out watt-hours. watt-hours are the sum of what that amount of stored capacity can do with that much voltage behind it. A 1.2V 2250mAH NIMH cell has 2700 mili-watt-hours. A 3.6V 750mAH li-ion cell also has 2700mWH.

Eric

Thnx dude, that answered my question. So out of the three i think ill go with the rechargeable 16340 then. So going back to my second question lol, where did it go? i still want to know someone's opinion on torches made in china like the
[link removed by moderator]
and
[link removed by moderator]

itsmejaytee said:

So going back to my second question lol, where did it go?

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I edited it out, is where it went.

It was expressed in an unfortunate manner, which was likely to attract adverse comment. You have now rephrased the question in a more reasonable way, so it may stand; however the 2 links may not, and I have removed them as they do not belong here.

If you take a bit of time to look around the other sections of the forum, you will find discussion on a wide variety of lights, almost all of which are better than the 2 examples you gave.

one more thing I wanted to say about those voltage and mAH ratings on cells. Keep in mind that many cells are overrated in the capacity department, some more than others, RCR123s are pretty much all overrated, the highest tested capacity I have seen of a RCR123 size cell is ~600mAH, even if they say 880mAH or 1000mAH on the label...

DM51 said:

I edited it out, is where it went.

It was expressed in an unfortunate manner, which was likely to attract adverse comment. You have now rephrased the question in a more reasonable way, so it may stand; however the 2 links may not, and I have removed them as they do not belong here.

If you take a bit of time to look around the other sections of the forum, you will find discussion on a wide variety of lights, almost all of which are better than the 2 examples you gave.

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ohh okay i didnt realize that it was inapporpriate, and i apologize if i was being disrespectful, it was not my intention at all. Well can you tell me why it was inappropriate? and why the links are not allowed?

mdocod said:

one more thing I wanted to say about those voltage and mAH ratings on cells. Keep in mind that many cells are overrated in the capacity department, some more than others, RCR123s are pretty much all overrated, the highest tested capacity I have seen of a RCR123 size cell is ~600mAH, even if they say 880mAH or 1000mAH on the label...

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wow really? so how do i know for sure what to believe? ive seen advertisements saying 3.0v/3.6v/3.7v all with a different price. and i thought 3.7v @ 1000mah was the best it can get? it was more expensive then the rest of them too... bummer. i hope i dont cross boundaries again here... but are the batteries made in china good? reliable and what not? like i bought a package with a charger + car adapter + 4 cr123a 3.7v 1000mah batteries for like $25 shipped which is a killer price, but im just afraid of the quality.

the 3.7V AW brand cells rated at 750mAH are of good quality and will fit most any light that will support them. They are china made, but are from a reputable source (CPF member AW ) There are others on the market that outperform them slightly, but are slightly longer and may not fit all applications. Their real capacity is around 550mAH, which is pretty close to average.

since you already bought those, I suggest just giving em a whirl. Keep in mind that Li-Ion is most likely to have problems during charging, so if a cheap cell decides to explode, it would be while charging 99 out of 100 times. So to minimize risk, just put your charger in a flame-proof container if possible. (I never do personally, but should)