DIY Blue Laser Trouble! Help, Please!

[SpaceMonkeyBob]

I built a 1W blue laser using this video on YouTube and the parts listed in the description: https://www.youtube.com/watch?v=BYuvHFiyfoQ . The batteries I used are 880mAh and were listed as being 3.7V but when they arrived turned out to be 3.6V (the video also links batteries which are 1000mAh but I thought that 120mAh less shouldn't make a difference). After building the laser, I put on my safety glasses, put in the batteries and turned it on. There was an initial flash of light, which was as bright as the sustained output shown in the video but then it dimmed to being about as bright as your average 5mW laser. I tried re-soldering the connection between my driver and the ring but this made no difference and the laser still had this flash.
This is my first laser build so I may have made an error without knowing it.
Help, please!

 

[Cyparagon]

The cells you chose weren't the issue. Sounds like your driver and/or wiring might have shorted against the case. The diode is likely dead, but the rest of the device should still be functional, provided you take the necessary steps to electrically isolate all the wiring when assembling it the next time.

 

[The Lightning Stalker]

Does it flash like that every time you turn it on?
Did you charge the batteries?

 

[SpaceMonkeyBob]

If the diode is dead then should it not light at all? I don't really know the much about lasers so I'm probably wrong

 

[SpaceMonkeyBob]

Yes, it flashes like that every time (but it flashes for less time in succession until it doesn't flash and is only about as bright as a 5mW laser) I've been looking at the chargers for the batteries but I can't see which ones are better, could you recommend one please?

 

[The Lightning Stalker]

There is nothing wrong with you diode. You need to
charge your cells.

The Nitecore chargers are very good. Also, this one works,
but doesn't have the safety features and build quality
of the Nitecore, but is cheep and works. I have been
using it to charge my cells so far. The other thing is
you have to replace the cord to use it in the US.

 

[SpaceMonkeyBob]

Okay, I'll give the charger a go. Thanks for your help