Why Did My Laser Pointer's Beam Dim So Quickly?

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Discussion Overview

The discussion revolves around the performance and longevity of a 5mW laser pointer, specifically addressing the rapid dimming of its beam after short usage. Participants explore potential reasons for the observed decrease in brightness, battery performance, and the accuracy of product claims regarding battery life.

Discussion Character

  • Debate/contested, Technical explanation

Main Points Raised

  • One participant notes that the laser pointer's beam dimmed significantly after about 30 seconds of use, raising questions about battery efficiency and the accuracy of the product's advertised specifications.
  • Another participant inquires whether the advertisement specifies the intensity of the beam over the claimed three-hour duration.
  • A different participant argues that the beam's brightness diminishes rapidly, suggesting that at the current rate, the beam would become unusable in approximately five minutes, contradicting the advertised duration.
  • One participant asserts that the advertisement is misleading, sharing their experience with a different laser pointer that also had poor battery life, attributing the issue to the inefficiency of the laser diode.
  • Another participant mentions that red laser pointers generally have longer battery life compared to green ones, implying a difference in efficiency between laser types.

Areas of Agreement / Disagreement

Participants express differing views on the accuracy of the product's claims and the reasons behind the rapid dimming of the laser beam. There is no consensus on the underlying causes or the reliability of the advertisement.

Contextual Notes

Participants reference specific battery types and their voltages, as well as the performance of different laser colors, but do not provide detailed technical specifications or measurements to support their claims.

Who May Find This Useful

Individuals interested in laser pointer performance, battery efficiency, and product reliability in consumer electronics may find this discussion relevant.

hl_world
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I got a 5mW (class 3A), 650nm laser pointer yesterday and it came with 3 AG-3 button cells and over a day, it was on for about 60 seconds, maybe more however I noticed the beam wasn't as bright as it was when I first put it on. Over 30 seconds worth of use, it seemed to dim further until I replaced the batteries with some AG-3s that came with another product and it was noticably brighter. The 3mm white LED wasn't affected.
The website I ordered it from said its battery duration was 3 hours (it's the 2 in 1 at the bottom). It also said it came with 3 2.5v watch batteries (I thought AG-3 cells were 1.5 volts).

Why did the button cells lose their power so quickly?
Why do the AG-3s cause the laser beam to dim instead of allowing it to be at a constant intensity?
Did the website get the facts wrong?

Thanks for any replies
 
Computer science news on Phys.org
Does the advertisement tell you about the intensity of the beam for the continuous three hour duration?
 
No, but we're only talking about roughly 90 seconds for the beam to half its brightness at this rate, the beam will dissipate by 5 mins not 3 hours.
 
The advertisement is a lie. I have laser pointer running on two AAA batteries and it lasts for less than ten minutes. The laser diode is simply a power hog, inefficient at that.
 
Thanks for your help.
 
Red laser pointers last longer than green ones .
 

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