Which Pila(s) to run SNII guilt free?

I have a PM out to trade my SNII but don't honestly think I have a shot.

I might be able to order up Pilas and a Charger if I ask really nice.

Which batteries to get the proper voltage and current???

The trade has been shot down in flames.

Size wise if three stacks of three will fit in a bored out 3D, then Pila 150S cells look like the right size. But if I read something else correctly, they charge to a nominal 3.7V

The SNII uses 3x123 at 3V nominal for 9V. I already tried and it won't even flicker with 6V. (WHOOPS! - I didn't try hard enough - it will light on 6V just not very bright.)

So two 150S at 3.7V each is 7.4V which may not be all that much less than the 123s under load.

I think I have a plan if someone would just confirm it....

Two Pilas will charge to 8.4v!

7.4 could be too much depending on the bin of the led, and smoke it as the pilas can produce a lot of current b/c they are li-ion.

You'll more than likely need a current regulator. Either 1 pila and a boost, or 2 and a buck.

That's just Effing great. There isn't even an easy way to have a rechargable SNII.

If it means anything, it's an original SNII that I got from Wayne through an Ebay auction as long as two years ago. It still has the 123s it came with (down to 8.49V unloaded out of the light - and 5.4x flash amps). The amp reading when I first hit them in the light is about 850ma but starts dropping off pretty quick.

Even though 123s can be had fairly cheap online, I can't afford to order any. I rarely USE any light that doesn't have NimH or Alk.

The SNII wouldn't be at all bad to use if there was a rechargable solution. Otherwise somebody make an offer!

don't do it, you will kill the 5watt emitter!

voltage is not only factor. even thought voltage of 2x li-ion is lower than 3x CR123. li-ions will kill emitter due to very low internal resistance. VS primary lithium's current is limited by internal resistance

:sigh: I shall try to get permission to order some 123s from Battery Station, as the SNII is pretty nice with good batts!

just because a light is direct drive doesnot mean it's not regulated.

in SNII's case two items are regulation current delived. one is CR123 internal resistance. Other is Luxeon's VF, which determinds amount of voltage/current allowed forward.

Original SNII's used high VF luxeons, but will not survive use of 2x 18650's 25+ amps discharge rate per cell.

another example of a very well regulated direct drive light is barbolight U-09. which uses 3x NMH C cells known for a flat discharge curve, mated with 3x Kbin luxeons to closely match VIN. this results in long running even beam for most of battery cycle. very simular to a light with voltage regulated board.

Last question then. Is resistor that is needed able to be in the tail? Because the heatsink is very well attached to the M*g body...

Otherwise I will see if I can pull the trigger on some 123s.

If you can isolate the battery spring from the tail cap. Like put a resistor between the battery spring and tail cap. Problem is, on very freshly charged Li-Ion, 4.2 volts each (8.4v total), then on settled 3.6 (7.2total.) That's a big difference. So either you have resistance that protects it from 8.4, then it dims down a lot when it settles, or you have the resistance set for 7.2 volts, and only put in the cells when they measure 3.6 volts, or risk frying the luxeon..

See my thread where you posted for an idea of how to put in a step-down circuit. The CC taskled circuit may be too big for a C mag though.

IsaacHayes said:

See my thread where you posted for an idea of how to put in a step-down circuit. The CC taskled circuit may be too big for a C mag though.

Click to expand...

The TaskLED CC will fit in a C Mag easy with a HotLips or O-Sink, it's smaller than a nFlex. You may run into a problem with the heat sink used in Bluk's SN's from what I recall it extends a little deeper into the tube and it's not hollow on the back side like they are.

Later
Kelly

SN2 was really made to depend on 123's internal resistance. There have been some SN2 like lights with regulation electronics. That's the way to do it if you want to use rechargeables. But you lose the SN2's simplicity.

What did you want to trade your SN2 for? Hmm.

How about any of the "3.0V" RC123? Big a current again?

A LUXIII running on 1.5V cells would certainly be nicer. If the same 2C size it would be VERY nice. Otherwise I just gotta get some 123s online!

I've only been exposed to two "3V" li-ion cells. they both had very low mah capacity and were low performers

Just to throw out there, though I'm sure you wouldn't want to do it... You could sell your real SNII for a decent chunk and buy a SNII clone with a regulator so that you could run two 18650s. Then you can have cheap/free runtime and ultrabright goodness together...

But you lose your real SNII.

Yeah, maybe I could.

I just got read the riot act about my attitude lately. And I'm not even sure WHY I'm ready to go postal. I don't really need all this just now. So I'm just gonna forget about it.

It would be a b*tch to get it all together anyway.

Only trade I could see is for another 2C, this one with a 3W and some fancy convertor/regulator thingy. Otherwise scwew it!