Sunday, July 24, 2011

TEC ACCESSORIES GLOW PELLET KIT - TRITIUM INSTALLATION WITH NORLAND 61

I have previously done a review of the TEC accessories glow fob.  A GITD pellet is contained with in this glow fob.  I prefer tritium which constantly glows and does not need to be 'charged up' with light.  Tec accessories sells a glow fob pellet kit, for replacing the stock GITD pellet with something else.

I did a post here on how to temporarily install a tritium vial into one of these empty glow pellets.  This solution has been working reasonably well, but I've decided to glue the tritium in permanently with some norland 61.  Having tried green, blue and yellow tritium, I've decided to go with green as it is definitely the most brightest and most noticeable out of all the colours.

Here is a video on my technique for installing the tritium into these empty glow pellet tubes.  I do admit my technique could do with a bit of refinement... cleaning up the blu-tack is bit of a pain.








Just to recap, here is where I get my stuff from:
-The 3x23mm tritium is from:
http://www.cpfmarketplace.com/mp/showthread.php?170374-For-Sale-Tritium-Vials
-The TEC Accessories Glow Pellet Kit from:
http://www.tecaccessories.com/products/product.php?II=33
-Norland 61:
http://www.cpfmarketplace.com/mp/showthread.php?232854-Norland-61-Optical-Adhesive-for-Trit-installation

Summary of tips to install the tritium:
-Use a bit of blu-tack to block off one end of the empty vial
-You can use a flat end of a toothpick (or similar device) to neaten up the blu-tack if you have pushed it in too far
-Hold the empty vial at an angle, flow the Norland 61 slowly from one side. Let gravity slowly flow the liquid down to the end of the vial. This helps to avoid trapping dead air at the end of the vial.
-Only fill the tube about 1/3 of the way
-Gently insert the 23x3mm tritium. The Norland 61 will flow up the vial as you push it in.
-Leave it upright in bright sunlight or use a UV light to set the Norland 61
-Clean up the blu-tack. Use other larger bits of blu-tack to help pull it out. You can use a toothpick or a small brush to help remove the residual blu-tack
 -Top up the rest of the tube with Norland 61, set it again in UV light or sunlight.


Here is link to a PDF made by TEC accessories on various methods of using the glow pellet kit:
http://www.tecaccessories.com/PDF/TA_DIY_Kit_Trit_Project.pdf

Tuesday, July 5, 2011

18650 BATTERY COMPARISON

18650 BATTERY COMPARISON

Review of Protected Soshine 2800mah 18650 and Protected Trustfire 2400mah 18650



BACKGROUND

The Ultrafire WF504B which was reviewed earlier, uses a 18650 battery.  I also plan on posting up reviews of some other 18650 flashlights in future, so I thought it would be a good to do an article on these batteries.

For those of you not familiar with the term, '18650' refers to a lithium ion battery size.  In theory the battery should measure 18mmx65mm and be cylindrical (I believe the '0' at the end of '18650' is a reference to the shape).  You will often find there is some variation in the actual size of 18650 batteries.  Some 18650 have a protection circuit which will add further length.  Labels and packaging can also affect the size.

18650 batteries are most commonly found inside laptop battery packs, but they have also been taken up by the flashlight community for powering flashlights.  The benefit of these batteries are they can be very energy dense... they can hold alot of energy for it's size.

Before using lithium-ion (li-ion) batteries, it is important to familiarise yourself with the different sorts of li-ion batteries, how to use them safely and how to prolong the life of the batteries.  If care is not taken, some types of li-ion batteries can vent and explode!  At the end of this post, I've included a few articles and threads with further info on li-ion batteries.

I received a couple of different 18650 batteries from Dealextreme for review.  Included were the protected Soshine 2800mah and protected Trustfire 2400mah (black/red/flames packaging).

I was interested to compare these to some other 18650 batteries I have, including the same Trustfire 2400mah, but older and heavily used.


PACKAGING

The packaging for the Protected 2400mah Trustfire batteries is quite rudimentary.  They come in a two pack with shrink wrap around the outside.



The packaging for the Protected 2800mah Soshine batteries are more professional.  They come in a two pack in a clamshell packaging.  A bonus battery case is included.




TESTING METHODOLOGY

These batteries were all initially charged on a Pila IBC charger using the same channel on the charger.  They were then discharged on an Accucell 6 charger at different discharge rates (0.2A and 1.0A).  The Accucell 6 discharges the cell until they reach 3.0V (under load).  You should note some batteries such as the panasonic NCR18650 and NCR18650a can be discharged down to 2.5V.  Since the Accucell terminates at 3.0V, in theory these types of batteries can still be discharged slightly further and provide more capacity. The redilast 2900mah are based on the panasonic ncr18650.

I have included a rough estimate on how heavily used the various batteries are. 

I have to say the older batteries have seen some significant use and moderate abuse.  The unprotected blue 2400mah ultrafire and protected 2400mah trustfire (X), have seen quite a few cycles, some of which they were deeply discharged.  The more heavily used trustfire (X) and was then used with trustfire (Y) in a 2x18650 flashlight (only for a few cyles).  Trustfire (Y) had not been as heavily used as trustfire (X).  Do note; it is NOT recommended to use two poorly matched batteries in a multi-cell light.  I feel this incorrect use of these two batteries, may have result in some damage to both the trustfire cells.


RESULTS






CONCLUSIONS

Under lower current draw (0.2A) conditions the Black/red/flames Trustfire do provide close to the advertised capacity.  Under 1A current draw they still provide around 2200mah or more.  There is some doubt on how well these batteries keep that capacity after many cycles.  My older black/red/flames trustfire have lost a significant amount of capacity, with one developing high internal resistance.  I do have to say these older batteries have been through some abuse. 

For under $10 for two (shipped), they do represent a good buy, if you accept they may not last as long.  (It would be interesting to test my redilast 2900mah after they have been through a similar about of cycles and abuse, to see if these more expensive cells do indeed last longer.)  You should also note some people report there to be variation between various batches of these same batteries.

In my samples of the soshine 2800mah batteries, they are quite short of their rated capacity.  In my tests I only get around 2400mah from these cells.  I have a feeling I have gotten an older batch.  After charging the batteries to 4.20V, they do drop down to 4.13V after resting for a period.  This is a significant drop in voltage and may indicate they are older or used batteries.  Considering the soshine 2800mah are more expensive than the trustfire 2400mah, I feel I can not recommend these batteries.  There are better buys elsewhere.


LINKS:

Here a few articles on 18650 batteries

http://batteryuniversity.com/learn/article/lithium_ion_safety_concerns
http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
http://batteryuniversity.com/learn/article/lithium_based_batteries


http://www.candlepowerforums.com/vb/showthread.php?312835-Beyond-the-basics-for-Li-ion-safety
http://www.candlepowerforums.com/vb/showthread.php?178133-Are-Li-Ion-Batteries-really-dangerous
http://www.candlepowerforums.com/vb/showthread.php?35282-Li-Ion-FAQ-amp-Safety

http://www.redilast.com/index.php?option=com_content&view=article&id=51&Itemid=85
http://budgetlightforum.com/node/1825



Links for buying the protected soshine 2800mah and protected Trustfire 2400mah:


http://www.dealextreme.com/p/soshine-protected-18650-3-7v-2800mah-lithium-batteries-with-case-black-2-battry-pack-31896
http://www.dealextreme.com/p/trustfire-protected-18650-3-7v-true-2400mah-rechargeable-lithium-batteries-2-pack-20392