100% power rumor

Hello @All

can someone tell me whats about the rumor that run the laser with 100% will harm the laser and reduce lifetime.

I run my laser for months with 100% with no issues and it just doesnt make sense to me (technically) why it would reduce lifetime.

I mean, they are made for it, right?

Using a neje 30w laser.

Hi Alexander,

It’s really an issue with physics. For C02 lasers with glass tubes the gas can deplete faster if the laser gets pushed too hard as well as not being cooled enough. It’s more of a J curve on power. at 80% it gives a perfect balance for my lasers. I push my lasers hard but after 8 years of doing this I have enough data showing tubes pushed past 80% will loose power sooner. I’m on my 10th tube with one of my machines.


I’ve run my diode laser at 100% power most of the time, as the manufacturer provided for such circumstances when designing the machine. Once I got the CO2 laser, I learned that 65% power is the maximum safe level, also per tube manufacturer specifications, not per seller specs!

According to my search, you have a diode laser and you can run it at max.

There’s nothing magical about the 100% number that damages diodes. However, there are reasons for running below 100% duty in order to increase the potential diode longevity.

A few things to consider:

  1. Diodes degrade from the moment you start using them. Even at lower duty loads. They are in constant degradation. The variable then is rate of degradation.
  2. Diodes themselves have manufacturing variance that can increase or decrease their actual working lifespan vs statistical life expectancy. DOA diodes are not unheard of.
  3. Calculated life expectancy of diodes is based on a very narrow set of conditions. Nichia, the premiere manufacturer of such laser diodes, calls for a recommended operating temperate range of 20-30 degrees C. Thats basically room temp and slightly higher.
  4. Heat is the single biggest factor in degradation and whether or not expected lifespans will be hit.
  5. Consumer modules are typically being driven harder than diode spec. And with designs that include dual-diodes or other elaborate designs heat dissipation becomes more difficult.
  6. Market forces are compelling laser module manufacturers for increasing performance at reduced costs. Most reviews are done within a short period after receipt of the laser. This isn’t necessarily conducive to a focus on reliability and longevity.
  7. Most laser manufacturers warranty their products for 1 year. If thought of as a consumable then there’s no need to hit the 70K hours mark or higher that the expected life expectancy of the diode is spec’ed to.

Having said that, the rationale for reducing the power level is to mitigate overdriving and easing the cooling burden in order to keep overall temperatures lower with the expectation that this will reduce degradation. This approach is true for pretty much all manufactured goods. Running things at less than 100% duty cycle increases longevity… or rather reduces the chance of premature failure.

To the extent that these laser modules are “made for it” to run at 100% power all the time is contingent on the quality of the design, the validation process, and how close your operating conditions conform to test conditions. Reports of premature failure are all too common. But then again, if all you care about is the ability to run at 100% power for <1 year then maybe that’s fine. It’s all a tradeoff.

Keep in mind also that if pressed, Neje themselves say not to run at 100% power continuously. There’s a different topic from someone who reported on this.


‘Most’ lasers are advertised at max test wattage vs max work wattage. Working wattage will give you a relatively long tube life. Max test wattage will get you a nice shinny EXPENSIVE glass paperweight.

Do a power test to find your percentage equaling your working wattage and act accordingly.

What do you own that you run at 100% when you run it. Whatever it is it won’t be for as long…


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Many devices are engineered to run at 100%. The exhaust fan for my laser is one example. It has no adjustable power control. The fans in all the computers are typically 100%, although the CPU and GPU often have internal controls. Diode lasers are usually designed for maximum rated power, per the manufacturer of the diode laser I own.

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Ok, run it at 100%.

Good luck


This isn’t really measuring the same thing. Single speed setting doesn’t necessarily equate to running at 100% of max duty cycle. In fact, equipment designed to have continuous load are designed in with overhead to accommodate for those extreme duties. In other words, the single speed settings is south of 100%.

I would characterize this more as diode lasers are usually designed for maximum rated power under the very specific conditions that they’ve defined. For example, Neje themselves while claiming extremely long laser lifespans also advocate not running at 100% for more than a few minutes at a time.

I have no doubt a manufacturer could design and build a laser module that could run at 100% of rated wattage continuously for the entirety of the 70K hour expected lifespan but it would not be at a price point that any hobbyist or even most industry applications would tolerate. Then add in the complexity of most of the common manufacturers overdriving the diodes and expectations go down farther.

Here’s an excerpt from an analysis done on laser diode lifetimes to illustrate more the relationship between heat and diode degradation:
Note that these temperatures are much higher than what would be the range for diodes typically used in consumer laser modules but the effect would be the same.

I should have clarified one other point. My diode laser manufacturer suggests that one hundred percent program power is acceptable, as the diode is rated to five watts, but is capable of more than six to seven watts output power. This effectively means that the software setting of one hundred percent is the maximum one can “dial in,” but the diode will not be operating at full capacity.

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I see from your profile you have an Emblaser diode laser. I don’t have direct experience with them but they seem a reputable company. Do they explicitly state that they expect continuous duty at 100% for the entire expected lifespan of their laser?

From the FAQ on their website they state a planned diode lifespan of 5K to 7K hours. I assume they’re using Nichia diodes or possibly a comparable brand but Nichia expect their diodes to last 100K hours under proper conditions. I assume this to mean that Emblaser has designed-in a degradation factor that accounts for this difference. Assuming the lowest end of the expected lifespan, 208 days of continuous 100% duty would be impressive without noticeable power loss. I couldn’t find anything on published test results, however.

To their credit, Emblaser lists a diode warranty of 3 years although it seems they charge you for the privilege based on their prices. I could see a situation in a commercial setting where a laser is driven on average 5 hours a day for that 3 year period. I’m curious what results people are seeing.

Maybe a better question is what is 100%. Generally it’s considered the maximum possible.

Anyone that’s been around any kind of engineering knows that the design of a product has a ‘target’ and that cannot be the maximum.

If you want to make that ‘target’ you have to design with ‘latitude’ for changes in environmental and variations in parts/construction etc…

If you need 100cfm from a fan and that’s the 100% mark, it will probably fail…

Design for power is 117volts, and it goes to 125volts you are now over 100% of the ‘design’ criteria, unless you have latitude in the design, which means it’s not 100%.

A temperature change will also change the ‘loading’

Any design that is expected to last will never have a target design for 100%, it just won’t last.

If the manufacturer says you can run it at 100% continuously, you could probably run it at 125% for a shorter period and even 150% for even less time…

This is without common items, 100% of your cars performance 100% of the time… fat chance…

All of this is pretty moot as the assumption of what 100% really means is nebulous here.


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LED lasers do not have the same heat problems associated with exciting plasma in an inert gas in a blown glass tube. My little laser cutter has a “15 watt” LED laser (which might actually be closer to 1.5 watts in light output) and has a manufacturer rated 100% duty cycle.

I worked for Laserium for 10 years and dealt with calibrated lasers that put out 1 to 1-1/2 watt of light and this is similar in apparent (cutting) power. Those lasers were 240 volt 3 phase at 15 amps per leg.

They had glass water cooling jackets like many co2 lasers and were very susceptible to heat embrittlement such that if you ran them at 100 percent, you would halve the life of the glass tube. If you are cooling 15 watts of power consumed vs. 3kw consumed, you will have an easier time dissipating the heat.

If you dim your LED lights at home at 50%, don’t expect them to last twice as long!

Guessing you don’t believe the manufacturers statement on how many hours they will run?

If it’s supposed to run 100 hours, then at 50% power that will take 200 hours to make that manufacturers specified ‘on’ time of the device. Is that not twice as long or will it still only last 100 hours?. What about 20% or even at zero power?

At 50%, it’s ‘ON’ 100% when it’s on, it’s just on 50% of the time… a conundrum?

Take care…


I believe the manufacturer says you can run my LED laser at 100% for 100% of the time and it will last a long time.

(grinning cat face)


Even the question is problematic since the NEJE is a diode laser (NEJE does not do CO2 lasers) so it consumes 30W but the light output could be 4W or similar. These lasers can run 100% all time if these die they can be replaced (probably with a stronger unit like 5,5W or dual diode 10W)

CO2 is a different thing that can be killed if overrun diode is no problem…

for CO2 lasers the real question is the current in the laser tube. 100% is the “maximum” output of the power supply which can easily exceed the tube’s maximum current rating. learned this the hard way…

I have a 50W chinese CO2 laser cutter. Sure the first thing I was changed is that I put an Ampmeter on it. I asked professional and they said that the 50W laser’s ideal amperage is abut 18-19mAh anyting over it will shorten the lifespan of the tube. (this depends on the tube itself…the smallest 40W tubes like in the K40 could not handle more than 13-14mAh the bigger overr 100W tubes can handle 22-25mAh) In Lighburn If I used the laser at 55-60% it was already 18mAh. Than I looked for the little hole in the laser’s high voltage Power Supply and put a little screwdriver in it and turned it a bit…powered up the laser and checked it …it took me about half an hour but now If I use Lighburn at it’s 100% capacity and my ampermeter does not go above 18,5mAh which is ideal I think, I just cannot overrun it like this

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Great that you restricted the power supply. Your tube always draws 18.5mA when it lases.

What you read on your mA meter is the rms value…


Sorry I don’t really get you…what do you want to say…did I do something you think is wrong you think or not???

I am really egar to learn…