Twisty backup lamps and corrosion

[dimito]

Hi,

I'm looking for a backup light. A dive shop nearby sells lights from Light For Me and I'm interested in the Backup XML light. This is an aluminium 1200 lumen light that takes 3 C-batteries and you have to twist it to turn it on. I currently have a tiny Xtar D18 and one of those cheap yellow plastic lights that I use as backups.

The problem that I have with the D18 is that when I dive in salt water it turns itself on and burns dimly. Because of this the light is starting to corrode really bad. I don't have this problem in fresh water. The plastic light doesn't suffer from the same problem because it doesn't conduct a current.

Do all aluminium twist lamps suffer from the same problem when used in salt water? Should I look at a different light? I use and Xtar D35 as my main light and I am really happy with it, it never let me down yet. I'm also interested in the Xtar D26, I think this will be a better choice, corrosion wise, because it has a push button.

Regards,
Dimitri

 

[Alastor]

Using a Scubapro Nova 700 R for about 100 dives with no issues so far. (twist on - rechargeable - all aluminium).

 

[extremetito]

I am not sure I follow the problem with the Xtar D18. Does the corrosion you refer to involve the internals? If so, there could have been a leak.
A backup light with 3 C cells would be a bit bulky for me. I recently purchased an Archon V10S from Banggood (Less than $30 including shipping to the US). I have yet to dive with it, but it uses a single 18650, and has a click switch and not a twist on. The LED is an XML with 860 lumens output per the manufacturer.

 

[fmerkel]

I'd say the Xtar has a short problem and is going through low grade electrolysis. This is not normal for a decent dive light but some cheap stuff will do it. Saltwater is making an electrical path it should not be taking.

You might find this useful. Review: DGX 600 vs Xtar D26 vs $22 eBay light
Lots of people using the DGX 600 without issue.

 

[Doby45]

Another vote for the DGX600, it is an excellent backup light and has excellent service from DGX. Twisty style with a single 18650 AND a charger for like $49US

 

[Storker]

Do all aluminium twist lamps suffer from the same problem when used in salt water?

Not IME. My backup light is a fairly cheap Subgear LED light with a twist switch. Have had it for ~2 years, always clipped to my shoulder D-ring, never had an isue

 

[dimito]

Ok, so with a good light it shouldn't be a problem then. Great news

Would 3 c batteries be too long? I thought it would be OK because it is about the same size as the Halcyon scout.

I prefer getting the light locally instead of online. The price in the shop is alright.

 

[fmerkel]

3 x C-cells is entirely a personal decision. My main backup is a UK SL3 which uses that. Been in my pocket for years and works fine. I probably wouldn't buy it now, go for something like the DGX600 most likely.
The real question is whether you think the light and the source is reliable.

 

[stuartv]

Twist on-off is not a problem in and of itself. The DGX 600 really is a great light.

But, I do like the Xtar D26 even better. And it's only a little more expensive.

I would definitely want a backup light to be way more compact than a 3 C cell light.

Since your D35 uses 18650 batteries and the DGX 600 uses the same, and you will only use your backup light in rare circumstances, I would get the DGX light, so you can just maintain one battery pool and keep them all charged together.

 

[kelemvor]

The problem that I have with the D18 is that when I dive in salt water it turns itself on and burns dimly. Because of this the light is starting to corrode really bad. I don't have this problem in fresh water. The plastic light doesn't suffer from the same problem because it doesn't conduct a current.

The only time I've had a problem with lights turning on is with plastic lights. Metal light bodies don't flex as much (I assume) and have not been a problem for me. I've never had one corrode. It sounds to me like your light is leaking if it's turning on, burning dimly, and corroding.

Most of my lights are twist on. I prefer pushbutton or magnetic switches, but all types work for me.