Note to self--change computer battery compartment o-ring more frequently than never..

[nolatom]

It seems they don't last forever, and I don't recall ever having changed it out--just changed batteries and put more silicone on it. It went blank and when I got around to opening it up, the compartment was very wet, which probably killed the battery since it was making "electric water"?

This is on a rather old Genesis ReAct hockey puck. So I got on Ebay and they had a new o-ring and battery for eleven bucks. And in looking all this up on Google, I saw on several battery-changing tutorials a warning to ALWAYS change out your o-ring when you renew batteries. Who knew?? Possibly everyone but me.


PS: I decline to say if this amazing discovery is related to a recent post about "some guy" who did a drift dive anyway, with a dead computer...
;-)

 

[bladder]

Good chance you fried more than the old battery if the compartment flooded with salt water.

 

[nolatom]

Uh-oh. Will find out soon I'm sure...

 

[bladder]

If a dive computer floods in saltwater your best chance of saving the computer is to rinse the comparment in fresh water ASAP because the salt water a) conducts electricity much more efficiently and b) causes rust almost immediately so there's a far greater chance of shorting out and damaging the internal components.

If you haven't rinsed the compartment in freshwater at all, the odds of your computer working properly is next to nothing.

 

[nolatom]

Sounds like bad news. Yes, salt water. I thought it was just a dead battery and so didn't open up the compartment til today, ten days later, and found it wet. I wiped the compartment dry. I will find out next week when new battery and o-ring get here.

 

[bladder]

You don't have to wait that long. Most dive computers use a 3V lithium battery such as the CR2450. If your computer does, you can test it with virtually any 3V lithium battery, readily available at Home Depot or any hardware store. The only difference between them is the diameter and the thickness. Take a short piece of 2 wire cord, strip a bit of insulation off of each end, hold the 2 leads firmly against the contacts inside the battery compartment where the battery touches them, and then put one end on each side of the lithium battery.

It will either power on and show the normal display or it will be DOA or give a jumbled display with weird symbols, missing lines, that sort of thing.

You should definitely rinse it with freshwater if it works. Just like any dive gear, the saltwater dries out and the crystals form in all those areas that you can never see or reach. I'm surprised that you didn't mention seeing any rust inside the compartment or on the battery you removed. That's a good sign.

For the future.. If a dive computer goes blank after a dive and it wasn't indicating a low battery condition it almost certainly flooded.

 

[JamesBon92007]

Since most (or all?) dive computers are oil-filled, then assuming it didn't short out, would a leaking battery compartment O-ring cause internal damage?

To OP: in addition to the other great suggestions you might want to clean the compartment thoroughly with a Q-tip dipped (only slightly wet) in isopropyl alcohol and make sure the battery contacts are very clean. I've had good results with a tiny piece of #400 sandpaper.

 

[runsongas]

most aren't oil filled these days, only remember the old uwatecs doing that and they were a giant pita to work on. although a battery compartment that is sealed away from the rest of the computer is becoming more frequent.

 

[bladder]

Yes definitely do the isopropyl alcohol thing too, I forgot about that. It has a drying effect and will pull moisture out.

You can put a small amount in the cap of the bottle, pour it into the compartment and swish it around, then pour out the excess and let the rest air dry.

 

[RayfromTX]

70% Isopropyl is 30% water. 91% may be better for the purpose. I'm not sure if it leaves a harmful residue. I would opt for distilled water and using dry rice as a desiccant followed by desiccant packs.