Archive for the light Category

Flashlight O rings and Grease

Posted in light, lubrication, technology with tags , , , on November 30, 2010 by marksun

O rings are used in most state of the art, high tech flashlights – the kind with the aircraft aluminum precision machined bodies.

The purpose of the o-rings are to form a tight, smooth fit for parts of the light that must move smoothly past each other, and to form a waterproof seal.  To have a reliable and smoothly functioning light,  keep the threads and o-rings clean and free of lint, dirt and moisture, and use the small amounts of grease on o-rings and threads.

Virtually all o-rings used in lights are made of synthetic rubber.  O rings for lights are seldom made of natural rubber (cost and durability) or silicone (cost and/or not the right mechanical properties).

  1. Virtually any silicone based grease or lubricant with or without PTFEs (or teflon) are safe on flashlight o-rings.
  2. Petroleum and mineral based greases are deemed to be less suitable because some synthetic and natural rubber o-rings are attacked by some petroleum based products.  carry risk in this application.  Manufacturers mainly recommend silicone based lubricants.
  3. WD-40 is petroleum based, is too light for this application, and may dry out the o-ring.

I use a couple of greases that I have in my collection of lubes:

  • Lube Gel – silicone grease with PTFE from Radio Shack (oem from a SYNCO).  This tube should last me about 40 years.
  • “Green Slime”,  a silicone PTFE grease used for RC car shock absorbers left over from my RC days.

In the short term, just about any grease will seem to work just fine.  The reason to consider what you use is that greases  tend to stick around for the long haul.  You don’t want the grease to melt down the o-ring to a gummy mess, since the time you discover it will be the time you will need your light the most.

Reference:  “Comprehensive Grease and Lube Thread” on the Candlepower Forum (CPF).


Rechargeable Li-Ion Battery Notes

Posted in house tech, light, note to self, technology on August 8, 2010 by marksun

This is a look at the AW ICR 123 750 mah lithium ion (LI) rechargeable cells that I use every day in a 4sevens Quark 123, a state of the art, single-cell LED flashlight.   I have two AW ICR 123 cells whichI use alternately to power this light.

The AW ICR 123 battery has built in integrated circuit (IC) over-discharge (OD) protection Does it work? Yes. I have used these cells to the point where the OD protection kicked in  somewhere between 2.5 to 2.8 V under load. A meter shows that after a few minutes, the cell gradually recovers to a resting voltage of 3V. There is a concensus on CPF that this is the correct behavior for an OD circuit.  At the same time most consider running down an li-ion cell this low to be damaging to the cell’s longevity.  Some of the more hard core CPF’ers would even throw out a cell that has gone this far.  What I’ll do is to do whtat most people do; continue to use the cell, rely on the built in protection of the AW, and replace the cell if it’s longevity drops unacceptably.  Otherwise the conventional wisdom of CPF is that the AW is about the best cell for longevity.  It would follow that this could be because of its OD protection aka PCB (for printed circuit board).   I think the AW is a good overall value for a rechargeable cell for lights.   Costs  more, protection works as designed.   ($9 from 4Sevens, $7 from Lighthound)

Another cell that is lower in cost than the AW and with protection circuitry is  is the TrueFire Gray RCR123. This cell reputedly does not have the same QA as the AW but it is cheaper and on average has a somewhat larger mAH capacity than the AW.  As far as cell life is concerned I haven’t read much about this particular TF.  This cell is longer than the AW – there is discrepancy in its dimensions. May be a better value for the Quark’s  ($5.21 from Deal Extreme)

I use TF’s 18650’s in two other lights (Quark + 18650 tube and a Fenix TA21).  Those are proving to be really good cells, great capacity.  Problem is they are MUCH bigger than the  single 123 lights.

The AW 123 capacity is a bit lower than ideal … I get a weeks use without an OD, but  I have a few times now forgotten to charge and get the blink out as the protection circuit kicks in.  The question is how much damage is done to the cell – i.e. affecting the overall cell life.  I am in the middle of this now, we will see.  My impression is that the 123 capacity has been affected, but my records are not good enough to check this out.

CPF Thread: AW RCR123 750mAH Actual Capacity

Name   Size       V     AvgV mAh PCB amps

CR123  16340 4.2  3.7      750        5

Anti-explosion Vent/PTC Module
protection PCB with high current threshold of 5A +/- .5A
button top for better contact
steel bottom plate for wear protection

There is good information at CPF about cell capacity (in mAh) and run times under load (in minutes) in this tread.

Information  here shows that AWRCR123 750mAh cells have the best run-times over the long haul, but fall in the middle in cell capacity in the discharge curve tests under loads of 250, 500, 750, and 1000 mAh. From a practical standpoint the AW cells really have a capacity of around 550 mAh and not 750mAh.   The grey TrustFire cells are a bit larger – longer by 1.5 mm or 3mm with two cells.  This may account for their better mAh testing – possibly slightly larger cell size.

Appendix from CPF

Size Information and other info
Batterystation: 34.4*16.7
DX11670 (white TF):35.9*16.7

DX8683 (grey TF):35.8*16.6 … the grey trustfire, AKA
Trustfire Protected 16340 / 880 mAH 3.7v   36.2mm 16.3 mm (possibly some variation in size) $5.21 (8263 is the SKU #) from deal extreme (undervoltage cutoff ~2.75v)

AW:34.3*16.6  ( $6.99 at lighthound, $9 at 4sevens)

Other CPF anecdotal information
DX 11669 White Trustfire 880mAh — not good, lose capapcity – higher voltage under load but lower capacity
DX 8683 Grey TF) … longer than normal and don’t fit some lights – otherwise good value protected cells, expect some quality control issues (some cells die early)
DX Ultrafire R123 880 — also gray, overall poor performance
Solarforce 880 mAh — OK
AW 750 — best
KD have been found to not hold up well

DX == “Deal Extreme”
KD == kaidomain

Lithium-ion batteries are everywhere now. If you use a cell-phone,  laptop or ipod, you use lithium-ion batteries.   If you have used these things a while or are a heavy user of these devices,  you have noticed that this years batteries are better than last year’s  batteries, but still leave something to be desired, namely capacity and durability.  Capacity determines  how long the device can be used before recharging (ideally “forever”).  Durability determines how long the battery lasts before you have to buy a new one (ideally, also forever).   Here in the real world batteries have limits on capacity and durability.

LI also has limitations that raise safety concerns for the average person for certain uses, like flashlights.

The main problem with LI in general is that if the cell is drained (discharged) past a certain point, it can become chemically unstable, short out internally, and burn itself up, or worse yet, explode. The second main problem occurs when recharging the cell: if recharged past a certain point (overcharged), it can become chemically unstable, short out internally, burn itself up, or explode. As long as one stays away from these danger zones however, the technology is perfectly safe.  Before getting too worked up, LI is used everywhere from BlueTooth devies;  you put the device with it’s LI battery in your ear;  cell phone (the LI battery device is next to your head), and laptop computers (in your lap).  But rest assured, the manufacturers have these Li-Ion devices well under control so you don’t often hear of a problem known in the industry as (ahem) ignition.

This is not true of the hobby applications however  like radio controlled cars, airplanes, helicopters, or flashlights.  Here size and weight restrictions, and the hobbiest’s notorious tolerance for danger, drive a market for applications that are not fully protected, and this is true of flashlights.

Lights in particular are driven by design compromises in a fickle market.  There is a market that wants to use primary cells and not rechargeable ones.   Primary single use cells, unlike the li-ion cells, can be discharged to zero like any other cell without danger.  Much of the world prefers this ease of use.  Hobbyists, OTH, like rechargeable cells because they are cheaper to run over the long run, because they are the state of the art, because they are “greener”, as well as more demanding technically, and therefore more interesting.

Battery and Light Links

Posted in light, technology with tags on May 3, 2010 by marksun

This is is the best site I know of  about the current rechargeable battery chemistries and charging information.

For AW Li Ions cells that I use, this is a pretty good link

I have lights from 4 Sevens : including two “Quarks”  which are a series of modular LED lights featuring interchangeable parts to support different battery types in different combinations  (CR123, 18650, AA, 2xAA, etc) to power the same LED “head”.  They feature different switch types as well, the so-called tactical switch, and standard “clicky”.

DSD Charger for Lithium Ion 18650 and 123a

Posted in light, technology on March 27, 2010 by marksun

This is a note to self type of article related to my hobby of  collecting and playing wit expensive state of the art LED flashlights.  Lights use batteries so eventually those of my kind get delicate lithium ion rechargeable batteries, which in turn require chargers. I have  the infamous DSD charger for charging 18650’s and 123’s liIon batteries for lights. It gets a lot of hits for bad quality control from the Candlepower website hobby community,  which are fully justified.   The first unit I got never worked.  The replacement unit worked for a while, then the power supply brick crapped out.  Since this happens to virtually everyone who owns this unit, it is  common knowledge  that a Nokia compatible charger (which I have in my junk box)  is a reliable substitute.  This thing is cheap; $15 full price;  you get what you pay for.  Once you locate your Nokia charger  and luck out with a unit that actually works you’re good to go.  It’s based on the CS213 chip, which is amazingly difficult to find information about.  You get the feeling that it was a chinese knock-off that made the rounds in the early days of Li-ion embedded batteries.  It does however work.

From CPF  the “DSD board basically just implements the application circuit shown in the CS213 datasheet. Based on that, the charging behavior one should expect from the DSD is constant current charging until the cells reach 4.30V +/-0.04V. The charger then shuts off (no constant voltage phase with the DSD), with a nominal 150ms detection delay upon reaching the overcharge voltage limit. If you leave the cells in the charger, when the cells drop below 4.10V +0.06V/-0.04V, the charger starts to charge again. Once the overcharge voltage limit is reached again, the charger shuts off. And the cycle continues. The charge current level is determined by the power supply that you plug into the DSD.”

At some point, I am likely to  replace this relic with an expensive  “hobby” charger ( I already have two good RC chargers) that can charge anything.  Until then, this will do.

CPF article:

This link for the data sheet worked as of March 2010:

LD10, 18560 4sevens tube

Posted in light on March 26, 2010 by marksun

4 sevens order came in today (1st class mail) 6 days delivery from Sat order.

LD10 –  XRE Q5  120, 9, 47, 94  lumen light
18560  4sevens battery tube
123A lithium rechargeable battery spare

Fenix LD10 – My first impressions are good – a nice feeling, compact, but not too compact AA light.   With a GP2200 AA nimh  and the same led as the ta20, it has  a beam comprable to the Fenix TA20 VI setting. This light is larger than the P1D, my first Fenix, but small enough for EDC.  It’s about 2cm longer than the Quark 123.  The LD10 has crenelation on both the front end and tail end – a  subtle weaponizing design which gives it a small but significant macho edge over the Quarks.  Overall the Fenix lights feel a bit more refined than the Quarks – little things, smoothness of the anodizing, the faceted tube sections.  This would be a good light for an open ocean voyager, or as an EDC.

The LD10 has  two twist selectable modes, high/strobe, and  4 lower, to flash/sos.   Overall the two modes make the light usable in everyday life … walking at night, extended reading which requires for me between 18 and 50 lumens .   The flashing modes are interesting, tolerable for that reason,  but  more or less useless in day to day application.

18650 4sevens tube.  I’m using it to convert a Quark AA2.  Installing is initially a little confusing since the tube is a different design.  Where the 2xAA tube was open at both ends, the 18650 tube is closed at the negative battery terminal. The battery is inserted from the front of the tube instead of the rear. The switch goes over the closed end of the tube. The tube has a clip on it. The clip retainer ring must screw down tight or the light will not switch on.   Couldn’t hurt to ship a little diagram with it.  For me it’s a good upgrade but not a no-brainer at $25.  Based on the usage I get with the Fenix TA20 and 18650’s, I expect to get much better battery capacity than I’m seeing from my current niMh AA inventory along with a brighter max output.  The Quark’s have really excellent low light options so higher energy performance with approximately the same footprint is good.  The AA2 tube will go into the civil defense kit along with the pork and beans,  gas stove and radios.

o ring lubes

Posted in light, technology on December 31, 2009 by marksun

I’ve got Fenix and Surefire lights with aluminum bodies and rubber o-rings.  Threads and o-rings require lubrication every so often.  The main considerations are that it provides lubrication for the o-rings and threads which may get a fair amount of rubbing over time.  The lube should be chemically inert for the material so it does not attack the o-ring, it should be non-toxic in case you hold the light in your mouth (we all do that), it should stay put (grease and not oil), and be waterproof.

Lots of lubes qualify and many do not.

Rubber o-rings should not be lubricated with petroleum based greases because of the possibility of chemical interaction and breakdown of the o-ring material.  Silicone based greases are best for this application.

Last go-round I used Green Slime from the RC-Car toolbox.  This works fine, but it’s expensive and since I don’t have a lot of this, I’ll reserve it for RC car shocks.

I tried the white FG EP bearing grease … works fine but it’s mineral oil base with an aluminum complex thickener – did not see adverse effects but over time it may get to the o-ring.  Otherwise it’s great grease for a lot of things.  Probably OK.

Recently I found an old tube of  Archer Lube Gel with Teflon (Radio Shack).   This is at least five years old, maybe even 10, in perfect condition, has the right specifications and has been tested by others.  It came in a 3oz tube and I have at least 2+ oz left.

This is a Synco product.  See for a description.   This stuff is non-toxic, non-corrosive, inert, won’t wash off, disperse, break down, or turn rancid.  does not attract dust, impervious to water and salt water, superior adhesion-stays put, -45-650 degF.  It is non-petrochemical and non-silicone.  It is safe on plastics and rubber and metal, can be mixed with other lubes. Primarily it’s a PTFE in a gel suspension. It is fairly thick – translucent clear white.

Candlepower forums posts show this is works fine for Surefire and Fenix o-ring lights. I’m sure it’s fine for the threads too.

incandescens at the ancestral home

Posted in house tech, light on April 26, 2009 by marksun

2AA maglite hanging by the phone, classic ever-ready with magnetic strips on slide switch – dead in a drawer- awaiting resurrection, a rayovac – in service and functional, an Energizer “Hardcase Work” 4AA  in mom’s room, a purchase by my sister.  This last is a practical size – too big to lose-  ruberized, swivel head, pistol grip.