New Surefire on the way

[computernut]

I just ordered a Surefire A2 Yellow/Green. I'm hoping it gets along well with my E2L. I'll have to let them fight it out for a position on my belt.

I was torn what sub-forum to post this in... LED or Incan... went with Incan because it's the main beam

I'll have to say it's this forum that gave me all the info I needed to make the decision. lovecpf

Thanks!

 

[Patriot]

Sure can't go wrong with either of those!

 

[Outdoors Fanatic]

You're going to love that sweet incan beam...

 

[FAAbUlights]

You are going to love the color temperature of th A2's main beam. I wouldnt be surprised if you decide you like it better outdoors over your E2L.

 

[mwaldron]

The A2 is an awesome light, I'm not carrying mine as much as I was but I still think they're great lights. Do yourself a favor and pick up a Strion kit from FM for it, it's a nice bump in output power.

Y-G is the only color I want and don't have, it's an interesting sub beam color that seems to work great in darkness.

 

[Zeruel]

For some reason, I was misled into thinking NEW Surefires on the way. How naive of me...

 

[computernut]

Thanks guys. I think I'll keep it stock for now but I'll have to check out the Strion adapter if I'm not happy with the brightness.

 

[computernut]

Just brought home my new A2 from the post office.

Things I've noticed so far:
- Yellow/Green LEDs are very dim, hardly can see them in daylight. In the dark they aren't too bad, definitely easy on the eyes.
- The diameter of the body is a bit bigger than my E2L, fits my hand very nicely.
- The incan throws some heat almost instantly, you can feel it on your skin when a few inches away.
- It's nice you can lock on the LED by twisting then give it little taps of incan if you want a brief burst of more light.
- A2 won't fit into the V20 holster with the lanyard loop on, have to figure out how to remove it.
- Beam is yellow compared to the E2L's Cree LED but it's just the right colour temperature I think.

Very impressed with it so far and I've just shone it around the basement a bit.

Update: Popped lanyard loop off, this picture helped:
http://candlepowerforums.com/vb/showthread.php?p=1438244#post1438244
Best tool I could find that had a narrow tip but still strong enough was the small flat screwdriver on my swiss army knife's corkscrew. Pushed it straight into the groove between the plastic halves, angled it a bit and off popped the bottom of the ring. Scratched up the plastic ring on a couple of failed attempts with other tools but no damage to the flashlight.

 

[dchao]

Hi computernut,

I have also just received my A2 Y/G a week ago. I bought mine to use with IMR16340's from AW. I would not have got it without the rechargeable option, and now there is one. Since LiMN can be used in series, whereas there could be problem with Li-Ion ones. LiMN's are also slimmer and do fit perfectly in the A2.

I like the Y/G beam and the color, but it's slightly too dim. So I got three NICHIA warm-white LED's to replace the Y/G ones, and moded these current-limiting resistors to deal with increase in voltage (from 6V to 8V). Now I can safely and more efficiently drive the LED's from either primaries and rechargeable.

Willie Hunt's LVR seem to work even better with 3.7V rechargeable cells. Here are the reasons:

The rechargeable RCR123's loss their voltage very quickly, they start out from 4.2V and quickly drop to 3.2V at the end of their life cycle. I remember, my 3.7V D26 bulb can only stay bright for the first 10 min from a fully charged Li-Ion battery. In comparison, lithium primaries already have a flatter runtime graph, and do not benefit from the LVR as much.

Also, when the LVR stops working for the primaries, the batteries still have quite a bit of life in them. IMO, this is quite a waste. This doesn't happen with the rechargeables. Because the high voltage, they will keep the voltage regulator going until the very last bit of the juice is drained from cells - 100% efficiency.

 

[SUREFIRED]

For some reason, I was misled into thinking NEW Surefires on the way. How naive of me...

Lol same here

 

[Illum]

The rechargeable RCR123's loss their voltage very quickly, they start out from 4.2V and quickly drop to 3.2V at the end of their life cycle. I remember, my 3.7V D26 bulb can only stay bright for the first 10 min of a fully charged Li-Ion battery. In comparison, lithium primaries already have a flatter runtime graph, and do not benefit from the LVR as much.

Also, when the LVR stops working for the primaries, the batteries still have quite a bit of life in them. IMO, this is quite a waste. This doesn't happen with the rechargeables. Because the high voltage, they will keep the voltage regulator going until the very last bit of the juice is drained from cells - 100% efficiency.

:thinking:

Conventional LiCoO2 rechargeable li-ions such as the RCR123A or 16340 will sag a bit under load...but IIRC only occurs when the current draw runs beyond the designed limit.

IMRRCR123A or IMR13640 LiMnO2 Li-ion only has about 550mah of juice...

Running them in the A2 sounds like a way to make short runtimes and possibly over discharged batteries...:thinking: especially noting that a li-ion is essentially dead at 3.2V. But as the cells decrease their voltage, the closer they reach the designed input voltage of 6V...so unless the cells shutdown the LVR will continue its work thinking the cells are full and ultimately destroy those cells in a couple cycles if you deep cycle them like this.

I hope LuxLuthor can chime in on this...hes the battery expert around here

hmm...while the LVR is a little discriminating on the CR123As it does not necessarily mean it left a ton of energy in the cells. Remember that its design intention is to be as conservative as possible under the assumption that new batteries isn't always readily available. Its a wee better than the conventional discharge termination of surefire's direct drive lights...but not by a considerable draw and its quite picky about cells. I'm not sure about these new "titanium innovation" cells but back then the A2 absolutely will not fire with the orange bodied titaniums

 

[Kestrel]

I hope LuxLuthor can chime in on this...hes the battery expert around here

I thought Mdocod was our Lithium Ion battery expert, SilverFox was our Lithium Primary expert, and LuxLuthor our incan bulb expert??
(Either way, CPF wouldn't be the same without those wonderfully helpful folks.)

Edit: And Size15 our resident SureFire expert, DM51 our thread police officer (bless him), Empath our guardian angel, and Greta the ultimate arbitrator.

 

[Illum]

I thought Mdocod was our Lithium Ion battery expert, SilverFox was our Lithium Primary expert, and LuxLuthor our incan bulb expert??
(Either way, CPF wouldn't be the same without those wonderfully helpful folks.)

Edit: And Size15 our resident SureFire expert, DM51 our thread police officer (bless him), Empath our guardian angel, and Greta the ultimate arbitrator.

well...Mdocod and Luxluthor are both...
Mdocod knows a great deal about li-ions in relation to effective utilization in lights. LuxLuthor seems to know alot about the inner functions of li-ions often in relation to lamps and is the only one I know around here with a battery welder...

good question though, now I'm confused:shrug:

 

[computernut]

Thanks for the tips guys. I might be looking for rechargeable solutions after the first few sets of batteries

 

[Illum]

I've always like the A2...but they can rack up on cells if you use it too frequently. Some years ago there was this rumor that the surefire A2's LED rings are already over driven on 2xcr123A and that 2xRCR123A might push them over the edge and burn them out.

If the LED ring becomes an open circuit then more power will be delivered to the xenon lamp beyond its design current/voltage and may burn it out prematurely. If you take your LED ring out then proceed to operate the xenon you'll see this two stage xenon effect analogous to a medium mode and a high mode.

Now of course of the 4 A2s I've owned I never once dared to try RCR123As [protected ones won't fit anyway] so I could neither believe nor deny the rumor above. Using just one A2, however gave me an abundance of near spent CR123As to work out in single celled lights...which became a hassle overtime.

Hoping for a more cheaper approach for that pure white 3300K "regulated xenon" white I've adapted to using a G2, 1x17670, and a Lumen factory EO-4 lamp. The HO-4 was out of stock or else I'd consider that. The EO-4 had near the same output as an A2 when compared to it, but the runtime only lasted about 15-20 minutes before it starts to yellow...oh well, back on the charger it goes and its all better:naughty:

 

[dchao]

Even the IMR16340 is rated at 550mAH, but it's voltage is 23% higher than 123 primaries (3.0V vs 3.7V). Given that the LVR is very efficient at converting excess voltage/energy into runtime by using PWM. We can expect the IMR16340 has a longer runtime than a primary 123 cell rated at the same 550mAH.

In fact that is true. My 2 x IMR16340 lasted 28 min before the LVR drops the brightness. BigWaffles's A2 runtime, using Surefire 123 batteries, lasted 45 min, before the light starts to drop. (Notes: SF 123 cells are rated at 1500mAH)

I was quite happy with the 28 min runtime using IMR16340's. I could use them at home, and switch to Lithium 123's when I go on a long camping trip.

Also acording to SilverFox's battery shootouts:

123 Battery Shoot Out

Li-Ion Battery Shootout (Scroll down to RCR123 section)

Li-Ion should sag more under load and ending voltage also drop more in percentage term.

And according to AW, IMR16340 is protected with lowest discharge voltage of 2.5V. I don't see how LVR can kill these Li-Ion batteries. In fact, when I took the IMR16340's out of A2 at the end of the runtime test, they were measured at 3.0V. Looked like either the protection had kicked in or the LVR had given up first.

 

[Illum]

And according to AW, IMR16340 is protected with lowest discharge voltage of 2.5V. I don't see how LVR can kill these Li-Ion batteries. In fact, when I took the IMR16340's out of A2 at the end of the runtime test, they were measured at 3.0V. Looked like either the protection had kicked in or the LVR had given up first.

2.5V?
gee...different chemistry

 

[Bullzeyebill]

I don't have it anymore, but my A2 ran just fine with RCR123's and bounce with lightmeter showed no difference in output compared to CR123's. Runtime was shorter, but cells never went below 3.0 volts (resting), when light dropped out of regulation. I had red LEDs, which were brighter with RCR123's, but possibly the 100 ohm resistors used with the red LEDs helped avert problems over driving them.

Bill

 

[dchao]

My replacement resistors are also 100 Ohm's.

It gives good compromise between 3.7V rechargeables and 3.0V primaries.

Let's look at the difference in current through the LED between rechargeable and primary:

<Rechargeable Battery>

max current through the 10 ohm tailcap:

I (max_rechargeable) = 4.1V + 4.1V - (Vf) / (10 + 100/3) Ohm

For my warm-white NICHIA LED, the Vf (@30mA) is 3.6V

I(max_rechargeable) = 8.2V - 3.6V / 43 Ohm = 107mA

<Primary Battery>

The Vf (@ 20mA) is 3.4V

I (max_primary) = 3.0V + 3.0V - 3.4V / 43 Ohm = 60mA


Therefore current through individual LED for rechargeable is 36mA and for primary is 20mA.

The LED's are over driven a little with rechargeable cells and within recommended range with primary cells.

With my WW LED's (rated 9200mcd @ 20mA), the outputs, I estimate is about 1-2 lumens.

 

[Illum]

be sure to factor in the resistor in the tailcap with your calculations
There's this wee 10 ohm resistor in the tailcap and you can't see it unless you break it apart. When the regulator sees voltage/current from the batteries through the resistor, it assumes the LED mode. Once you press harder leaf springs short out the resistor and the xenon comes on.

I'm not sure if the LEDs are direct drive...if so, then factor in the extra 10 ohmer.

Just out of curiosity, what was the stock resistor values? I have trouble reading SMT codes:shakehead