Atomic Cobalt 2 Battery Issue.

[oldpeanut]

One of my student divers' Atomic Cobalt 2 dive computer seems having a problem of battery not holding its capacity.

First experience - after fully charged the battery to 100%, went out diving 2 days later, found the battery status was only 87%, made 2 dives, battery capacity dropped down to 34%, next day made 1 more dive, the battery dropped down to 3%. To me, it looks like the batter has some problem.

Returned the unit to dealer and distributor for a check up and was informed that the unit needed a firmware upgrade and afterwards, it loses only 1% of capacity per day when fully recharged which is normal for the Cobalt 2 dive computer.

Second experience - fully charged the battery, next day went out diving for 3 days with total of 5 dives and found out the battery capacity dropped down to 5% only.

Based on these two experiences, is this normal for the Atomic Cobalt 2 dive computer? I really doubt it. Any feed back will be highly appreciated.

Thanks!

Terry

 

[Dr. Lecter]

What was the screen brightness setting for those three days/5 dives, and how much on time are we talking re: SIs, rinse tank, etc.? Regardless, 95% drain in 3 days does seem excessive.

 

[deeper thoughts]

interesting

 

[oldpeanut]

What was the screen brightness setting for those three days/5 dives, and how much on time are we talking re: SIs, rinse tank, etc.? Regardless, 95% drain in 3 days does seem excessive.

The brightness setting I believed is high. The first day 2 dives were about 45 minutes each with about one hour surface interval. The second day 2 dives were 50 minutes and 40 minutes, again with slightly more than 1 hour surface interval. The last day dive was 1 hour. The computer had never been left in a rinse tank, just quickly rinsed and hung up for drying.

Thank you again for your prompt reply.

Terry

 

[RonR]

Terry,

I replied to you also on the Atomic forum, but for the general interest...

Is this failure to hold a charge a consistent behavior or intermittent? And can you let me know the firmware version?

I'm going to assume that the computer was stored in a dry location, and not with the charging adapter in place. And that it was charged while dry- we did have one instance where the charging adapter was getting plugged in wet and causing electrolysis on the Cobalt. If the Cobalt is wet, it won't really go to sleep, but will keep sampling waiting to start a dive. That will run the battery down.

Let me suggest some diagnostics we can try. If your student just leaves the computer sitting overnight- not putting it manually into sleep mode, but just letting it sit- what is the rate of charge loss? It should be on the order of 1-3% per 24 hour period. After sitting like this, if they dip the front into water without touching any buttons, does it wake to the dive screen? That would indicate that is is in true sleep.

If the Cobalt 2 is run at maximum display brightness, it will run the battery down in diving, but not this rapidly. It might last 10-15 hours or so of diving. Can you let us know what the brightness level is set to?

Can you connect to USB to download dives and update firmware?

I'm going to PM you with some instructions for accessing a battery diagnostics screen, if they can go to that and take a picture for us that will give information on the battery and charging state, and tell us the power draw.

There are two things that I can think of that could cause this. One is that the battery has a high rate of internal discharge or is just weak and needs to be replaced. If that were the case, this behavior should be consistent. Replacing the battery is a easy thing to try- do you know if that was done when it was sent in before? The other is that there is a damaged component on the PCB that is not always allowing the Cobalt to go fully into sleep mode- the display turns off, but the processor is still active. There are certainly some other components on the board that, if they failed, could cause a high current drain. So we will work at figuring this out and getting the problem fixed.

Ron