IQS #110-140 green pen laser mod

[steviedezie]

When i saw these going on sale for 38.99 from IQS i jumped on them. (maybe 2-3 weeks ago) Without a LPM to test output i can only trust that the specs are correct. Overall the seller is pretty spot on or even underspec most of the time. this one was supposed to be 110-140mW and it seemed pretty right on to me. But being a modder/DIYer at heart, i couldnt resist chopping up the pen to make it use 1 1 10440 Li-ion. so here it is:

it got much brighter and actually lights dark paper. i'd say its right on the 140mW rating while running on 2 AAA's i was probably doing 100-110mW.

overall i great buy and a easy mod. well worth under 40 bucks free shipping plus hes in california...got mine in 2 days.

 

[joeyss]

I'm thinking of doing this to my #90-105 green pen that I got from him.but I don't know if it will handle the current.

 

[steviedezie]

a 10440 battery shouldnt juice up the diode that much. its not really the current draw, but rather the increased voltage which results in increased current to the diode. In my case i saw 30-40mW increase (guessing) so i have no idea if my pen will last long or not. So far 4 hours of ON time since mod and still kicking strong.

 

[qumefox]

You probably won't hurt the module itself, but the driver will probably die. No 3V driver i've come across has liked 4.2V AT ALL. However the problem is fairly easily remedied by adding a diode in series with the battery, which will drop the full charge voltage the driver sees down to around a tolerable 3.4V

 

[joeyss]

^and then there's the issue of the heat from the extra voltage.

 

[qumefox]

Well that's typically what kills the driver. Last one I tried had hot glue on it, and I it had actually melted and was dripping off when driven at 4.2v.

 

[joeyss]

Aren't there 3.0V lithiums of that size? They should give about 3.3 Volts or so.

 

[steviedezie]

qumefox is right on about using a 10440 as well as his remedy (diode in series with batt.) reason i didnt do it is since its a pen with a momentary button, it sees a very short duty cycle...usually around 10-15 secs. I've personally never had it on for more than 30 seconds. If you wanted a longer duty cycle or for maximum life then the only way is to use a diode in series to drop the battery voltage.