How to identify 2/3/4 cell MagLED modules?

My buddy came over with his 3D MagLite that he bought a MagLED module for. On close inspection, his module has a laser engraved number on the side of it that started with a 4. Did he buy the wrong module? What would happen if he did buy the 4 cell module and uses it in the 3D MagLite?

Looking at the various MagLED modules we have my 2 cell module has a "2", my buddy's other 3 cell MagLED module has a "3", and then there is this module.

Also, what would happen to my 2 cell module if I installed it into my 3D MagLite?

Yes, I tried a search.

PCC said:

Also, what would happen to my 2 cell module if I installed it into my 3D MagLite?

Yes, I tried a search.

Click to expand...

Thanks, I figured as much.

if you run the 4-cell module with 3 cells, it will just be dim. I ran my 3-cell in a 2-cell once and it was dim but worked fine.

That's interesting. I ended up trading for that "4" MagLED drop-in and, compared to my brother's 3D MagLED, it's brighter. Yes, I was surprised. I was expecting the opposite. Maybe my brother's batteries are run down?