8 hours ago, Chris Ross said:

Sorry, you actually do need liquid water to setup an electrochemical reaction, a thin film of salt is enough to do it as salt is hygroscopic and will pull water out of the air. But unless the humidity reaches 100% you won't get any condensation and even pure water needs a little in the way of salts to become conductive enough to facilitate dis-similar metal corrosion. I'm quite familiar with corrosion mechanisms in my line of work. It won't happen if the contacts are dry. Leaking batteries of course can cause it as they leak electrolyte. Regarding copper, it is quite resistant to sea water corrosion, but tarnishes quite readily which can reduce conduction.

Here is a collection of cotton tip swaps sprayed with a bit of contact cleaner and 30 seconds of rubbing. None of these ever flooded or got even a little bit wet. My camera room humidity is typically about 40-45%.

Inon 330:

Backscatter HF-1:

OrcaTorch v710v and Backscatter MF-1 (Rub/spin the battery housing contact surface on a towel):

My suggestion it to do some preventative maintenance on all of your strobe and light electrical contact surfaces to avoid problem. Don't forget to clean the contact surface of the batteries too. I rub the batteries contacts on a scrap towel on occasion, when I happen to about it.

Edited 15 hours ago15 hr by Dave_Hicks

Good points.

Several years ago I ordered a set of "scratch brush" electrical contact cleaners and carry a couple of those with me on dive trips. I only had to use them once on another person's strobe, but they can clean contacts that suffer some corrosion or other issues. They are cheap, light and small and can be purchased on Amazon and at other places. May be worth sticking in your gear somewhere, in case Coke or contact cleaner or alcohol isn't available after a leak?

As far as preventative maintenance goes, I know Sealife warns that:

1. IMPORTANT UPDATE – Clean battery contacts every time before charging

Applies to all Sea Dragon lights with 1200+ lumens and Fluoro-Dual Beam models.

Clean the gold-plated contacts on battery and inside battery compartment EVERY TIME before charging the battery.  Use a clean cotton cloth moistened with isopropyl alcohol to thoroughly clean contacts.  Not cleaning the contacts will permanently damage the gold plating and result in the device not powering on.

DO NOT store the device with battery installed.  Remove battery before storage.

Left contact shows black spots resulting from not cleaning the contacts.

Kind of boosts my appreciation of my old Inon lights with their AA batteries. But I know Lithium and massive lumens are the future.

Just to compare my strobes here's my Z240 cap contacts and a swab that just wiped them over, this is the first time I've cleaned them:

I can only see the slightest trace of residue being picked up. I agree though if you are getting corrosion on contacts regular cleaning will help. My routine with these strobes is that every time I pull the batteries the o-rings are removed shaken dry checked and greased and the water left in the o-ring groove dried out and cleaned, then replaced and sealed up. Because I'm diving regularly, the batteries normally go back in the strobe. The strobe is 10 years old.

Even after soaking the strobes for 2 hours the water trapped in the cap between the edge of the cap and the o-ring in still salty (I've checked by taste). If I don't pull the batteries I end up with salt crystals in there as the water slowly evaporates. The O-ring on these strobes is not a super tight fit in the groove and it seems to me there is a risk of traces of salt water making its way inside the strobe unless I dry out the o-ring as described.

In the more than two decades I have owned a set of Inon D2000 strobes I have never cleaned them, flooded them or seen any sort of corrosion on them. My new S220 strobes are clean as can be, maybe in another twenty years I will give them a good cleaning. If I am still around to do so.

This was not a common problem with AA powered devices. It does appear to be an issue with higher powered lithium devices.

16 hours ago, Nemrod said:

I am not clear here. Did Backscatter state the specific reason the strobes quit working was "stained" contacts and that there is no other malfunction involved?

I was in contact with the service department before sending in the strobes and have send photos of the contacts (after cleaning with a Dremel tool and with alcohol). I was told the reason are the contacts, some "stain" from corrosion (there were still remains of this stain to see on the photos). According to Backscatter, this can happen even without direct contact with water (and there has never been a contact with water)...

At present the strobes are at Backscatter for repair and they will tell me the details after the repair. I will report here then...

Edited 1 hour ago1 hr by Architeuthis

11 hours ago, JohnD said:

Good points.

Several years ago I ordered a set of "scratch brush" electrical contact cleaners and carry a couple of those with me on dive trips. I only had to use them once on another person's strobe, but they can clean contacts that suffer some corrosion or other issues. They are cheap, light and small and can be purchased on Amazon and at other places. May be worth sticking in your gear somewhere, in case Coke or contact cleaner or alcohol isn't available after a leak?

As far as preventative maintenance goes, I know Sealife warns that:

1. IMPORTANT UPDATE – Clean battery contacts every time before charging

Applies to all Sea Dragon lights with 1200+ lumens and Fluoro-Dual Beam models.

Clean the gold-plated contacts on battery and inside battery compartment EVERY TIME before charging the battery.  Use a clean cotton cloth moistened with isopropyl alcohol to thoroughly clean contacts.  Not cleaning the contacts will permanently damage the gold plating and result in the device not powering on.

DO NOT store the device with battery installed.  Remove battery before storage.

Left contact shows black spots resulting from not cleaning the contacts.

Kind of boosts my appreciation of my old Inon lights with their AA batteries. But I know Lithium and massive lumens are the future.

The contact marked as "Corosion..." is exactly how my contacts looked (but the corrosion was much less intense in my case).

Here the photos of the contacts after cleaning, rests of the stain can still be seen (unfortunately I did not make photos before). One strobe was working after cleaning (upper photo), the other not (lower). Backscatter said better send in both since the problem will reappear soon...

Edited 1 hour ago1 hr by Architeuthis