Sanwu '3000mw'


Newly Enlightened
Jun 15, 2004
After hearing a lot of good things about Sanwu, I bit the bullet and ordered a blue 304 model rated at 3000mw, with 2 x 3.7v lithium batteries.

The outcome was a little disappointing....

The batteries appeared to be rechargeables, and not fully charged at that. The laser itself – solid, heavy construction but nowhere near 3w. I put that down to the batteries and put in a fresh pair of 3v Duracells, but the same result was evident: a beam that was around 150mw max.

The beam divergence is huge too. at 3 metres, the rectangular 'dot' was just under two inches wide, at the tightest focus.

Has anyone else had a similar experience? I did wonder if there were different power settings triggered by a sequence of button presses, but it appears not (there's one on/off button on the base).

I'm suspecting a faulty device or as someone suggested on Reddit, an incorrectly seated module. The beam fades after about 15 seconds, which is well under the duty cycle of a minute.

I double checked that I hadn't been shipped the wrong device – they do sell lower-powered models, but in a different form factor taking different batteries.

Customer service has been nonexistent. I have to say, I'm surprised – I'd heard a lot of good things about Sanwu.


Newly Enlightened
Jan 3, 2010
Welcome to the world of laser ratings. They are marketing numbers at best.
I doubt that any of the budget laser pointers produce anywhere near their rated level, more likely 10-20% if that.
Keep in mind that the US regulators set much more stringent limits on laser power, so what you see on Amazon rated at 10 mwatt may be advertised as a 100 mwatt item on a non US web site. My 1000 mwatt Sanwu was found to be 80 mwatt by another forum contributor who had the needed gear to measure the actual output.
That said, this Sanwu (green pointer) is more than enough to hurt the eye, so I keep the diffuser cap mounted and the key lock on.
The good thing is that it is great in the field, allows me to point out birds even in sunlit conditions, where normal pointers fail.

In your case, the power level you measure seems about normal, but the beam fade is not.
As the Reddit correspondent suggested, it sounds like an incorrectly seated module to me, the heat generated in the module is not able to leak into the rest of the body, so the unit heats up too much and shuts down.
I have zero expectations for customer service from Sanwu, they sent my unit in a plain manila envelope without a shred of documentation, not unexpected given the price and probably sensible for a metal tube with laser assembly, but no batteries.