SureFire batteries = can be used in SF LED after SF incan?

Guys,



This is a repost of a question from another board. I pondered putting it under the batteries section, but I put it here as it seems to deal more with surefire LED flashlights than it does the actual batteries:



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Surefire 123 batteries and LED lamps



I now have quite a collection of "spent" surefire CR123 batteries from daily usage of my surefire Z2, with it's standard 65 lumen, zenon lamp.

(If your not familiar w/ the operation of this surefire lamp, one may not understand that there is an enormous waste by tossing batteries that still have alot more power to offer. Appearently, from what I concluded, the zenon lamp needs full voltage to ignite and opperate. Low battery = no light. This is very often the case, but I've also had the light get dim on occation, until it dark, but most offen it just stops working all together, until I change the cells, of couse.)

I need a bit of feedback from sure fire "LED" owners re: there usage.

Does the LED flashlight just quit working, from low batteries, or does it grow dimmer and dimmer till it's dead.

I hate tolling out these things if I can help it.
If the LED flashlights will "work" with the low voltage of the cells I pull out of my Z2, then I'll pick one up as a back up.

I also remember hearing about a "lantern" that accepted 123's, that utilized an LED array to squeeze out every last bit of juice from these things.
Any links? Your truely,
too cheap.

(he later adds):

...Keep in mind I'm looking into using the surefire line of led's. It's just my preference for torches.

I'd be actually more interested in using these in a head mounted LED arraingement. kinda like a minners helmet type thing.
I've seen nothing but crapy ones that use regular batteries.
I'm thinking that, with more homework, I may be able to come up with something I can adapt to use the 123's.
Over.

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This question was outside of my knowledge base, so I thought I'd bring it over here to see if someone can help the man.

Hope I didn't violate any crosspost regs. :sweat:

Thanks!

There is not a simple answer to your question.

One important consideration - all batteries experience voltage sag under load. As you draw more current, the voltage drops. All batteries also have a voltage curve vs state-of-charge that is fairly uniform for any given cell chemistry.

Nearly all incandescent lamps are "unregulated" - you simply apply voltage to them directly from the batteries and the filament burns brightly until the voltage sags and the filament doesn't get as hot, starts to dim, then (perversely) starts to consume more current when dim than when burning brightly.

Most LED lights have some sort of regulation. A simple resistor will choke the current for a given voltage to something the LED can handle. A regulator circuit takes a variable-voltage supply (like a discharging battery), corrects the output to a voltage the LED wants, and usually regulates the current to the LED.

There are other factors to consider - battery voltage always sags under load, and LEDs are typically lower-power than incandescent light bulbs.

So... you have batteries whose voltage has been beaten down by hungry incandescent filaments and they don't have enough voltage to make them glow... so you toss them into a LED light which manages to revive them? No. The LED isn't demanding the kind of power that the filament is (less voltage sag), and if it has a regulator circuit, it's not so sensitive to voltage anyway (your low open-circuit voltage at end of life. Net result, you can extract the last bit of energy from the cells that's of no use to an unregulated incandescent lamp.

Now, not all LEDs are created equal. Much of the behavior depends on what requirements the regulator has. If your friend on the other forum needs to know what Surefire light will "finish the job" on his not-quite-dead 123As, I think the E1L would be a good choice - it's the lowest-power LED in SF's lineup, so it should be able to work off cells too dim to light up a 6V filament.

Perhaps somone else can offer a better explaination...

If you have batteries that aren't completely dead (meaning they still manage to light an incan lamp, albeit dimly) you can put them into a LED light and have a chance that it will produce some light with those batts, maybe even run in regulation for a certain amount of time.
BUT this will depend on the regulation (if any) of the LED lights AND the desired current draw of this light (high powered bright LED or dim long-running?) AND also of the state of your "empty" battery.
Either way ... no harm done to the LED light, LEDs don't suffer if they are run under their spec, quite the contrary. So you can leave a LED light on until the last photon has escaped.

:cauton: One word of caution though
If you mix those batteries before putting them in a LED light you might end up using two cells (in case of a two-cell LED light) with different capacity left, and this could actually cause one of the cells (the more depleted one) to be reverse charged which could lead to fatal failure --> explosion.
Never mix batteries of different capacity ... meaning you got two "empty" cells frm your incan ... you put both of them in a LED light, and you're good to go ... but you would not want to throw them in a drawer with all the other "empty" cells and choose two of the lot to power your LED light.
Elegant solution is a one-cell LED light ... can't go wrong here.

Don't expect a great performance of said LED light though ... empty batteries are ... well ... empty.

bernie

I'm not sure how long the "dead" batteries will run the LED module, but with some "dead" batteries I've managed to run a 2nd gen KL3 module on a C2 Centurian with suprisingly good results. The batteries wouldn't give any life to the p60 lamp, but gave about 60-70% of the potential power to the KL3.

I know this beause I ordered a KL3 module and surefire brand batteries at the same time from two different vendors. The KL3 came first, but I couldn't test it because my C2 was as dead as a doorknob with the P60 lamp, not able to give even a dim light. I tried putting on the KL3 anyway and it came to life! :rock:

You should be able to run a LED module on some used batteries, just don't expect full power.

You could go to Target and buy an Inova X5. It will drain the last bit of energy from those batteries and I find that its flood-type beam is very useful around the house.

Greetings Sleestak,

I have a E2D and when I change out it's batteries I run them in my G2 with a Bugoutgear 3 watt LED. I know its not a SF LED but it's host is. Anyway I usually get about 30-45min of runtime in regulation with the spent batteries IMHO. I put these used batteries in an SC1 carrier for use in the G2 and I mark them so I don't mix the used pairs.

I have 2 9Ps. One a stock incan, and one with a KL3 (latest variant). The KL3 gets the incans leftovers. This usually squeezes about another hour of regulated burntime out of my batteries.

Enjoy

I called SF tech support SF uses 2.9 volts as thresholds for incans, anything below 2.9 v measured on a good quality multimeter you are in mid to low LED's

After my G2 can't run anymore, I switch the batteries over to the L2 or U2. I can still get the maximum light output, but only for a short time.

If the batteries you are using are near the end of their life and you want to squeeze the last bit of juice I would have said you want an unregulated led - as the voltage sags more current is demanded so voltage sags more - so output drops off very quickly, you see very little life from your ex-incan cells. Unregulated sees you run the led direct with no losses of power in any circuitry.

The OP wanted to know what SF light to use... IIRC the L1 on low mode is unregulated..? Uses 1 cell to heed bernhard's warning, a regulated high mode to get the last useful power out of the cell and unregulated low to drain the sucker dry.

Of course, if I'm wrong I'll just blame it on the fact that it's 3am here and for some reason I'm still up... :sleepy:

I routinely save my discharged CR123's from my incans and use them in my E1e with KL1 head and McGizmo two-stage tailcap. They last quite a while.

Are there any leakage issues with sucking 123s dry?

Chris201W said:

Are there any leakage issues with sucking 123s dry?

Click to expand...

So far so good with the SF 123s I have been using. All put through either Incandescents or LEDs, with no problems whatsoever.

King of CR123 battery drainers is still original ARC LS first run. which uses a version of dat2zip's MM series board. first run's contain two ciruits in parallel and will support 1.2V nmh.

Amazing how ARC LS first runs still is one of world's most versatile lights. will support 1x AA, 2x AA, CR123 and R123.

MM series boards are voltage regulated so VF of luxeon will determind current used. semi regulation will not be as flat as current regulated boards, but will have the advantage of draining cells almost completely dead.

I dont know about anyone else, but I have found that when the light just stops working the batteries are no good at all. If it gradually dims they are okay. Many times I will be using one of my Surefire incans. It will be working fine. Turn it off and stash it. Go to use it minutes later and it is dead! WTF? First time this happened to me, with an E1, I thought the bulb had burned out. Changed the battery on a whim and it was fine. Tested battery on a volt meter and it was flat. This only happens to me with Surefire batteries, never with Duracells. Duracells seem to last longer too. Problem is the cost of the dang things!

cbxer55 said:

I dont know about anyone else, but I have found that when the light just stops working the batteries are no good at all. If it gradually dims they are okay. Many times I will be using one of my Surefire incans. It will be working fine. Turn it off and stash it. Go to use it minutes later and it is dead! WTF? First time this happened to me, with an E1, I thought the bulb had burned out. Changed the battery on a whim and it was fine. Tested battery on a volt meter and it was flat. This only happens to me with Surefire batteries, never with Duracells. Duracells seem to last longer too. Problem is the cost of the dang things!

CBXer55
Oklahoma City

Click to expand...

Yeah, I've had this a lot. But in multi cell lights, it's usually only one cell that has died completely, the other still has a bit of life to give. Though it's not a huge amount left, it's enough to run an led for a while.