cr123a battery/charger question

[iTorch]

OK, so I am looking at getting a 120p, this requires a 123 cell, now I am wanting a charger but have run into a wall of questions, so am seeking answers, have not found after reading the welcome mat stuff...

1) maH what does this mean, does a higher number indicate a better batt, i.e 700 mah vs 1000 mah whats better and what does it mean?

2) 3.0 v vs 3.7 v whats better/what do i need?

I have found two cahargers in the shops over here, one is an ultrafire, has a swithch to swap between 3.0v or 3.6v and comes with 3.0 v 1000mah batts (two), the other is a no name brand that is 3.7v and comes with two 3.7 v 700 mah batts.
Is there any diff/what do i need for my 120P?

Also technical talk does not mean anything as I am not an EE.

Cheers

 

[mdocod]

have you bought the 120P already? can you throw me a link to what the heck it is (never heard of it though I'm sure it's something really obvious to someone else). In all great honesty, a 1xAA powered light is a lot more practical than a 1xCR123 light if you are gun-ho on going rechargeable. Li-Ion rechargeables in this format are pretty lousy performers.


[edit] never-mind I just looked it up.... the NovaTac I assume...
retracting the statement that was here.

 

[iTorch]

Sorry, a NovaTac 120P.

 

[mdocod]

ok... trying to formulate an answer here:

If you are really set on this light and running it on rechargeable, get a pair of AW brand protected 3.7V RCR123s. They are "rated" 750mAH, in actual use ALL RCR123s are more like 500-600mAH. Expect about 1/2 or less the runtime of a CR123 primary out of a rechargeable Li-Ion cell. The reason I recommend AWs brand is purely safety related. They are constructed with harder shrink wrap, use higher quality PCBs with a more protective design for the PCB than other cheaper brands, and they are one of the only RCR123 with full electronic PCB protection and an advanced PTC (pop-style vent/connection severing device). What this means to you is safer more reliable operation. Remember there is a reason they don't sell Li-Ion cells at the corner store. Buying and Using Li-Ion cells is a few steps above your typical consumer rechargeable cells in terms of the level of involvement the user ought to have as far as understanding the limitations of the cells and acting on those understandings.


think of "mAH" ratings as the size of the water tank, and voltage as the amount of pressure the water is under. try not to concern yourself too much with ratings of anything in this world. Your "100W per channel" stereo is actually only about 5W per channel. In the case of RCR123s, if it's rated 1000mAH it's a really blatant lie, 750mAH is what AW calls his, which is theoretically close to possible under a very light load. Still a bit exaggerated, but not as bad.

 

[iTorch]

So does that mean that the higher the mAH the longer the battery will theoretically run for before needing to be recharged/replaced and the higher the v mean that the light will be able to be used at max for a longer time, or it will be able to power a LED at max lumens for longer, before dropping down to a lower level?

 

[mdocod]

the 120P has a buck/boost style circuit, what this means is that it will regulate power to the LED regardless of the voltage of the cell (within reason).. On some flashlights, a higher initial voltage would mean brighter, on others it doesn't change anything at all. Higher mAH will generally mean that you get longer runtime before a recharge, but like I already said, you aren't going to get a RCR123 cell with anything higher than about 600mAH, sure it can SAY 1000mAH on the label, but it's an over-stated marketing driven lie. See a CR123 is going to deliver about 2.6V and about 1500mAH into the load of the 120P, while the RCR123 will deliver about 3.7V and about 550mAH. In the end the light will still use about the same amount of WATTAGE to run the LED, from the CR123 it will draw more current to get the same wattage, while from the RCR123 it will take advantage of the higher voltage and draw less current. In any case, a regular primary CR123 has about double the watt-hours capacity as a RCR123.

 

[mdocod]

sorry double post (rarely happens to me, got the best of me this time)

 

[iTorch]

that helps, my plan was to use the recharges to get the hang of the torch, free lumens to learn how to use, once I have got it sussed, say six months, them switch to primaries for normal EDC use, with recgarges in case I run out of juice between shopping...

 

[mdocod]

just use the rechargeable ALL the time, with the primaries in storage as backup for emergencies, like when the power goes out.