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Cobalt 1 help: What to do if your battery is dead

Discussion in 'Ocean Concepts' started by RonR, Aug 9, 2019.

  1. jimpeachey

    jimpeachey Instructor, Scuba

    # of Dives: 100 - 199
    Location: UK, England
    41
    1
    8
    Ron, the battery is definitely dead, it even looks like there may have been some corrosion in the body of the computer, although it will start when plugged into the mains or USB, it just wont charge. Do you know of anywhere online where i can get a replacement battery?
     
  2. RonR

    RonR Dive Equipment Manufacturer

    # of Dives: I just don't log dives
    Location: Washington State
    1,266
    472
    83
    Does it look as if the battery compartment may have leaked a bit and caused corrosion? If so one of the battery leads my have broken. The electronics are sealed from the battery compartment, so even if there was a leak there the rest should be fine.

    The batteries are a custom part with an integral thermistor. I'll contact you with re. sourcing, but basically it is through Atomic in Europe if you are in the UK.

    Ron
     
  3. jimpeachey

    jimpeachey Instructor, Scuba

    # of Dives: 100 - 199
    Location: UK, England
    41
    1
    8
    Atomic no longer have a European support office and will not provide a replacement battery. They have suggested i return the unit to the USA for servicing. Im pretty sure the cost of this with return packing would be more expensive than a new computer. Seems this one is going to go in the bin which is a shame. Although it has been an excellent computer i will have to go with another brand to ensure there is support. Very poor show from Atomic i think.
     
  4. RickH1

    RickH1 Garibaldi

    # of Dives: 1,000 - 2,499
    Location: USA
    3
    0
    1
    Don't know if I can just tag onto this chat. I am having the same problem. Cobalt 1. Been packed up for over a year, went to recharge and it says charged to 99% (after full overnight mains charge). when i disconnected the mains charger, it switches off and when i plug back it, its back at 0%. suspect battery dead, but I cant find anyone in Hong Kong that does maintenance. I saw your PDF on how to change the battery, how safe is that for waterproof integrity after the fact? I'm with Jimpeachey, shame to throw it away due to lack of support, but no point in keeping a cobalt paperweight.

    looking for support in Hong Kong
    Rick
     
  5. RonR

    RonR Dive Equipment Manufacturer

    # of Dives: I just don't log dives
    Location: Washington State
    1,266
    472
    83
    Rick,
    I suspect your diagnosis of a dead battery is correct. With a Cobalt 1 being at a minimum 6 years old, and being left to go fully dead (this is hard on lithium batteries), and with the symptoms you describe, that seems likely.

    Changing out the battery is no more challenging than changing the battery in an underwater light, or a camera. With care for the O-ring it is possible for nearly anyone. And the battery compartment is sealed from the rest of the electronics, so even if there were a leak, the rest of the computer would be fine.

    The issue is getting a battery to you. Or getting your computer shipped to someone who can take care of it. I'm trying to communicate with Atomic about options for non-US customers who need battery replacement. I haven't heard back, but with covid issues they are running on a partial staff. I will be contacting you about what options I can work out. With global shipping it just shouldn't be that hard.

    In any case, don't throw out that Cobalt! We plan to have a very attractive upgrade for any older Cobalts, in any condition, coming up. It may turn out to be quite valuable.

    Ron
     
  6. RickH1

    RickH1 Garibaldi

    # of Dives: 1,000 - 2,499
    Location: USA
    3
    0
    1
    Ron, appreciate you taking the time to reply.

    I think i can buy the battery here in HK (I work in cell phones and my staff say its a common battery) so might give that a try. is there a video anywhere on opening/reassembling the unit to access the battery? keep me posted on the upgrade options once they are available.

    thanks

    Rick
     
  7. RonR

    RonR Dive Equipment Manufacturer

    # of Dives: I just don't log dives
    Location: Washington State
    1,266
    472
    83
    The battery does come from China and as I understand has had several sources over the years, I don't doubt that the basic configuration is very common. What may be different is that we specified a thermistor on the battery PCB to monitor the battery temperature directly, as an additional safety mechanism, and if that thermistor wire is not there the Cobalt won't recognize the battery or charge. The connector is also a custom PCB with three sockets, but that would be pretty easy to fabricate. And the charging circuitry is programmed to the battery capacity and chemistry, so that would need to be a match. If you do find something that looks like a match let me know.

    Here is a link to an instruction sheet: Dropbox - BatteryReplace.pdf - Simplify your life

    Ron
     
  8. GregH12345

    GregH12345 Garibaldi

    # of Dives: 50 - 99
    Location: UK
    3
    4
    3
    Hi Ron,

    I hope you don't mind me jumping on this thread, and I really appreciate the other information that I've already found in this section, and your on-going support for Cobalt users.

    In terms of matching a suitable replacement for the EM72461P, could you confirm if the thermister is NTC or PTC please? I've tried to find this information online without any success.

    Regards

    Greg
     
  9. RonR

    RonR Dive Equipment Manufacturer

    # of Dives: I just don't log dives
    Location: Washington State
    1,266
    472
    83
    Hi Greg,
    The thermistor on the battery is NTC 10 k ohm. I'm wondering what the part # you refer to is, though. Is this a # for a replacement battery?

    Ron
     
  10. GregH12345

    GregH12345 Garibaldi

    # of Dives: 50 - 99
    Location: UK
    3
    4
    3
    Hi,

    Sorry, yes the EM724261P is the battery, as per this image.

    Thanks for the info, I might have found a suitable replacement battery.

    Will update the group if it works :)

    Cheers

    Greg.
     

    Attached Files:

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