Quote: (Originally Posted by
Shaunzxr)
Did a 75m dive today.
Delrin computers
40mins into dive, on the ascent HUD flashed red at me and I noticed primary was dead.
Ran the unit manually and after 5 mins the primary came back on. It reset itself and displayed no stop.
The batteries were new and worked fine after the problem.
There was no sign of corrosion when I opened the unit.
I feel this is a serious problem and wondered if anyone else had this on the delrin handsets
When you say the batteries were fine.. what was the voltage before the dive?? was the air alot warmer than the water??
You say it came back after 5 minutes.. did you ascend to warmer water??
after it came back on what was the voltage reading??
Has this happened only once??
These are questions to ask to help determine if its a handset problem or just a crap cell.. my personal recommendation is that if the voltage is less than 1.5v for an alkaline (when idle) on the surface change the cell.... I have seen way to many 1.5v batteries come out of the box at 1.4v and less...
With the ss cap and spring Its unlikely that you will see corrosion, also with the large surface area on the cap/spring contact issues are not that likely.. but some oxidation on the contact at the bottom of the battery compartment is possible and since its a AA cell there is a relatively small contact area.. and if the battery has any oxidation its possible that a "dead" spot can form... Use a pencil eraser on the positive contact in the compartment.. Pressure will warp the case slightly then release its deformation, so a contact issue is possible...
Personally I would like to see a spring loaded contact at the bottom as well.. to help isolate changes in the the case from the battery..
anytime a user replacable primary cell is used, the fact that its not a soldered contact means that contacts have to be checked regularly for oxidation..
On every dive computer that I own that has replaceble batteries I always use a bit of conductive lubricant on both the positive and negative terminals to reduce the change of a contact issue.. Don't use too much or it will create its own problems...
Before I started using it on my vr3, I had alot of intermittent lock ups.. on my explorer it stopped the occasional computer reset.. On both the explorer and vr3 I always had the lockup or reset upon accent.. usually somewhere around 50% of maximum depth...
with the limited info so far I would look at the positive terminal...