Sunlite Science and Technology

Penlight Questions
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Author:  admin [ June 15th, 2012, 11:23 am ]
Post subject:  Penlight Questions

Questions asked about Penlights are listed below.

Author:  admin [ June 22nd, 2012, 11:19 am ]
Post subject:  Penlights Switch Rubber

I had a penlight in my pocket. I heard a pop and looked the penlight switch rubber piece had a hole. What would cause this?


Penlight is sealed by two o-rings, the tube is air tight. When there is a sudden big change in temperature, like suddenly go from very cold to hot. Air may expend to a point that break the rubber cover. If you can unscrew the LED head a little and let air leak out from the LED side during a season like this, it will not expend the rubber cover.

Author:  admin [ June 22nd, 2012, 1:23 pm ]
Post subject:  Penlight has dim glow after it is shut off

Hello I have one of your Slim JR sunlight lights. It was left running for about one hour straight and when I went to turn it off it stayed with a very dim glow. It would stay this way no matter what I would do with it. Finally the battery's ran out. Now with new batteries it does not work at all. Can you offer any suggestions on a fix to this.

It is not supposed to be have dim glow when it is turned off. The dim glow was because of a small current leakage (less than 1mA) from the soldering residue on the switch. Since LED has much higher efficiency at low current, it will have a dim glow when the light is off.
We will send you a housing to replace it. You said with new batteries it does not work, you may put the batteries backward, the positive should go in first. This should have nothing to do the dim glow.

Author:  admin [ June 22nd, 2012, 1:46 pm ]
Post subject:  Penlight Flickering

I bought a sunlit slim jr. for our snap-on tool guy a few years ago. it works great for a while when you push the power on it will some times flutter, and go off . it's like the batteries don't make a connection all the time. i have to open it up and remove out the batteries and reinstall works good for a while and back to the same thing. i had this replaced once already for same reason. any answers?

The Slim Jr. typically run 5 hours continuously on each set of batteries. Afterward, the light still will turn on, but will flicker. You said after reinstalling the batteries, it will work good for a while, it sounds like the batteries are not strong enough, or are not making good contact.
Other things may also cause flickering.
---Batteries intended because of dropping, we have PCB spacer you can use to tighten the batteries.
---Dust on the batteries contacts, especially the positive contact. (the contact area are very small on AAAA batteries) 3. Build-up on the ---LED contact pad, you can scratch off the build up.

If you have tried all the above and still having problem, please set it in, we will take a look at. We have lifetime warranty on the light, this excludes the damage caused by leaked batteries.

Author:  admin [ June 22nd, 2012, 2:05 pm ]
Post subject:  Penlight spring weak

I have a "Sunlite" LED penlight. Have had light for quite some time, over a year. The spring inside the battery tube seems to be somewhat weak. Will you warranty the defect?

If the spring is weak, we will warrant it.

But sometimes if you hear rattling inside the battery housing, it was probably not because of the spring, it was probably because the batteries are intended because of dropping, we have PCB spacer ... ucts_id=92 you can use to tighten the batteries.

Author:  admin [ June 28th, 2012, 1:06 pm ]
Post subject:  Penlight LED

I have one of your Slim 1W Led Pen lights (65 lumens) and the led head is now faulty. I attempted to purchase this led head on line on your site and was a bit shocked to find that a replacement unit was $20.00. I regretfully accepted this price but was absolutely shattered that you were going to charge me $97.00. to ship it to Australia. Is there anyway this reduce this shipping charge to a reasonable amount? The penlight is very much valued by myself and I would regret discarding it due to expense.

If the light is flickering, there is big chance it is not the LED head. Please refer to the penlight flickering post. You can scratch off any build-up layer on the LED head contact pad to improve contact. Our LED head is very rugged. 99% percent of the problem is in the housing, either the switch, or the copper thread pull out. If you need housing it is

You may just need the PCB pad ( to tighten the batteries, or just need new batteries.

As for the shipping, it should just cost around 7 dollars to ship to Australia using post office first class. Are you able to choose this option online? If not, please email me your order. We can process it with post office first class, we will give you an email address to pay paypal.

follow up questions
Thanks for your reply. I have connected the led head to an separate variable power supply and the head is definitely faulty. I cannot select the cheap post option on your web site so if you could send me the email address to pay by PayPal ; that would be great.

The first class parcel through post office to Australia costs $4.56. Priority post office package will cost $16.95. A 1W LED (60 lumen)costs $20, a 3W LED (120 lumens) costs $26. You can pay to using paypal.

For this 3W LED head, if you are using constant current power supply to power it, the current should not be over 1A. we would recommend you use less than 5V power to drive the LED. Otherwise, the LED will be burnt.

Author:  admin [ June 28th, 2012, 1:09 pm ]
Post subject:  Slim LED fell out of the housing

I am a machinist and purchased a Sunlite Slim 1Watt from a Snap On dealer about a year ago.Problems.About a half inch from the end of the tube the light came apart.It appears two pieces are crimped together there.I super glued it and all was well for a while longer. Now intermittent light.shake,tap,ect for operation. Bought a new light today because gets used many times a day.I put the bulb assembly from the new one in the old one and still no go. I don't minding spending good money for top quality tools but feel this light is defective as it is still on the original
batteries. Can it be repaired?

We have lifetime warranty on it. We will repair or replace parts under warranty.

Here is the explanation: We have a brass thread piece embedded into the housing to improve the durability of the threads. The thickness of the portion of the Aluminum housing outside the bass pieces is much thinner than the rest of the housing. The link to the housing is

If the LED head is twisted into the housing too tight and the flashlight dropped many times on concrete floor, the aluminum may be enlarged, pushing the brass piece came out of the housing, you can unscrew the brass piece and use the same LED.

Our new version 1W or 3W white LED heads have a spring soldered to the contact pad, this way, you will not screw the LED head too tight into the housing, this will eliminate some of the problem mentioned above.

SlimLED.jpg [ 21.95 KiB | Viewed 20474 times ]

Author:  admin [ August 8th, 2012, 3:13 pm ]
Post subject:  Re: Penlight Housing warranty

Are the penlight housings warrantable? I'm a mechanic and the brass threads pop out the housing.

If the brass thread pop out of the housing, we will replace it under warranty. The rubber sleeve that comes with the Slim3W penlight will help to protect batteries from being indented and also will protect the brass threads.

Author:  admin [ September 18th, 2012, 10:56 am ]
Post subject:  Penlight warranty procedure

i purchased on of you're slim 100 lumens light's and the light worked fine, then began to flicker on and off.this light was bought from a snap-on dealer and he said it was just bad batteries.i purchased this light with duracell batteries and that is what has always been used with this light.long story short.the light was sent back to you for a warrant repair.the light was disassembled removing the thread insert and a letter was sent back saying that there was a battery failure.i find this hard to believe.there has never been any corrosion in the light that i could see.the thing that bothers me is the light was blue with the cover missing now the light i was returned was also blue but had the wrong make of batteris and the cover was on this a mix up is probably the cause but when i asked my snap-on dealer he claims that he has a bag full of these lights returned in the same condition. this was a 50.00 light on the truck and i do not feel that it has provided a life of service that would reflect you"re name.please respond with some kind of answer to this issue.


We see the penlight as three parts, the housing, the batteries, and the LED head.

When we received a penlight for warranty, we clean the LED contact pad and check the light using new batteries.
If the light still flickers, we replace the housing.
If the light works fine, we send back the original housing and indicate the cause of flickering is batteries.
If the thread insert came out of the housing and stuck on the LED head, we replace the housing and use the original LED head.

We don't return the original batteries back.

A battery failure does not mean battery corrosion.
Your original batteries may be weak, please note one set of batteries will run 5 hours continuously, afterward, the light will still turn on, but will flicker.
You original batteries may be indented on the positive tip, the light will also flicker because the bad contact between the batteries. If your batteries are still strong, you can use a PCB pad to tighten batteries.

The only case that is not covered by our warranty is when the LED is damaged by battery leakage. For unwarrantable light, we offer exchange. You can send the light back to us by yourself, if you use post office to mail it back, it will just cost you $1.95.

Author:  admin [ March 20th, 2013, 12:35 pm ]
Post subject:  Re: Penlight Questions

Hello, do you have any plans to produce a Sunlite Slim 3AAA penlight with an
HCRI or Nichia 219 type emitter?


we make high color rendering index Slim LED head, but may not have them in stock all the time, it usually takes 1-2 weeks to make a lot if we don't have it in stock. You can add this special request to the "specail instruction area" when you order.

we don't have plan to use Nichia 219 type emitter.

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