Can ARC-LSH use 3.7v Li-ion

This topic is discussed before and note general advice is no. But really want to know whether a 3.7v Li-ion will just cause ARC-LSH to lose regulation or it will damage the circuit or over drive the 1w led. I really want to insert my MP RCR-123A to my ARC.

Lots of people are doing it, and very few have had problems that I've heard about. A freshly charged Li-ion will overdrive the Luxeon as the board will go into DD till the voltage drops a bit. Seems like most stock LSH models came with a "K" bin vf though, so it's probably not as risky as some people say it is. PG said it would void the warranty, but that's a moot point now, and he was probably erring on the side of caution anyway.

That's not an endorsment though, so proceed at your own risk.

Peter

There are 3.0v R123's out there as well.

There is a thread that has all of the bin codes for almost each and every light here in the ARC forum. You can try to find it and locate what bin is in your light and go from there.
I used to have it saved, but after the overhaul it doesn't work anymore.
HTH

mut

I've stuck bare R123 li-ion's in most every flavor of Arc LS. including rare first runs with under 100 serial numbers.

all with no damage, your mileage may veri..

Tried my ARC-LSH with a MP Li-ion (about 90% charged) and it ran for 1hr 52min from slightly overdrive output initially to constant output and then triggered the cut off protection circuit of the Li-ion. The sudden turn-off of the ARC-LSH with protected Li-ion without any flickering or dimming is a drawback.

(1) Would this apply to all LSH model or case by case.

(2) Would there have other brands protected Li-ion suit to LSH which could allow flickering or dimming before turn-off.

The LSH was not designed for R123 cells since they were not available at the time. Using rechargeable 123 cells is not recommended for the LS series because it could damage the LED.

1) All rev2 models (LS2, LSL, LSH) would drop off rapidly. Rev1 units would drop off more gradually. This is because the rev2 was better regulated.
2) All over discharge protected cells should produce a similiar rapid drop off, unprotected cells would run for longer but the cell would likely be damaged by over discharge.

Pretty much any LiIon Cell with a safety cutoff (low voltage), will shut off the output of the LSH LED with little warning. Those without protection could be overdischarged, damaging the cell.

As the cell approaches ideal depletion, the voltage begans to drop at an accelerated rate for a given current consumption.

A light designed for r123 cells (like the Arc4), will either began to back off the output in advance of the cutoff (thereby extending the time to cutoff), or provide a lower regulated level that allows the cell voltage to temporarily rise above the cutoff (assuming the cutoff doesn't require a recharge reset).

Peter

Edmond said:

Tried my ARC-LSH with a MP Li-ion (about 90% charged) and it ran for 1hr 52min from slightly overdrive output initially to constant output and then triggered the cut off protection circuit of the Li-ion. The sudden turn-off of the ARC-LSH with protected Li-ion without any flickering or dimming is a drawback.

(1) Would this apply to all LSH model or case by case.

(2) Would there have other brands protected Li-ion suit to LSH which could allow flickering or dimming before turn-off.

Click to expand...

Are there protected MP Li-ion cells?

Mine are not protected.

when using bare li-ion cells of any type.
you've got to yank cell imediately at first sign of dimming.

overdischarging will result in damage to cell, not light. at $4 per cell. not a big deal.

real danger is from using R123 with a low VF luxeon. If a real Hbin is used 1.75+ amps, a recipt for short life. probably taking out the 1618 chip too.

since most early luxeons were mostly in Kbin range. I've never hurt a stock LS using R123. your mileage may veri.

has anyone hurt a stock ARC LS of any flavor by using a single li-ion cell?