Underwater video lights showing signs of electrolytic corrosion

[Jak Crow]

I recently acquired two new video lights that I used during a dive trip. During the trip, I noticed that the lights began showing signs of electrolytic corrosion. I was wondering what would cause this to happen. I assume some kind of flaw with the light itself.

 

[tamas970]

Piece of steel nearby? Solution: get a little piece of zinc attached to a free metallic part of the light if possible

 

[Jak Crow]

No steel that I'm aware of. I'm just using it with my camera rig. Also, I have an i-Torch light that's not showing any signs of corrosion. I thought I had read in the past people experiencing this with some of the cheap 18650 powered dive lights.

 

[tamas970]

My cheap archon does not corrode. Paint is getting off a bit, but no corrosion. Anyway, zinc...

 

[3D diver]

If the battery and head unit are at different potentials (voltages) you'll get conduction & electrolytic corrosion via the sea water. A zinc anode may help.

This may be way off...but you might try reversing the polarity of your battery. If the controller is designed with a rectifier it shouldn't care and this might reduce the potential between the head and body. Or burn the whole thing up.

If you have one, a volt meter might show the potential difference between the head and body.