• Welcome to ScubaBoard

  1. Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

    Benefits of registering include

    • Ability to post and comment on topics and discussions.
    • A Free photo gallery to share your dive photos with the world.
    • You can make this box go away

    Joining is quick and easy. Login or Register now by clicking on the button

Fire on dive boat Conception in CA

Discussion in 'Accidents and Incidents' started by divezonescuba, Sep 2, 2019.

Thread Status:
Not open for further replies.
  1. ericinmich

    ericinmich Angel Fish

    8
    1
    3
    Plus, a smoldering fire with windows open could easily keep the wind moving away from a detector.
     
    rjack321 likes this.
  2. Mindless

    Mindless Angel Fish

    # of Dives: 200 - 499
    Location: Rocklin, CA
    14
    36
    13
    I alway use one of the fireproof Li-Po bags when traveling with Lithium Ion batteries and, while on board, charge the batteries inside the bag in the hopes of minimizing the risk of fire. I also don't buy cheap knock-off batteries.
     
    Gdog, Ayisha, Satrekker and 5 others like this.
  3. Louisville Diver

    Louisville Diver Nassau Grouper

    # of Dives: 200 - 499
    Location: Louisville
    74
    79
    18
    Something dawned on me this morning. My newer batteries tend to recharge via USB, which I'm assuming is always a protected circuit. Older batteries were direct plugins.

    I'm wondering if someone was charging an older-style battery by a 110 plug either into an unprotected circuit OR a surge strip that was past its prime (I've had to replace some - you should see the warping when they croak). You'd get some sort of amperage spike straight into the battery that way.
     
  4. dmaziuk

    dmaziuk Orca

    5,282
    1,801
    113
    Trickle-charge them at < 0.5C (edit: for less) temperature build-up. They'll live longer.

    USB 2 is 0.5A and at that current you shouldn't see much heat build-up during charging, but USB 3 is specced to 0.9A and "charging" ports can easily go to 2A. That's "fast charge" territory already -- though I'm told RC crowd runs theirs chargers at 4 amps and somehow they don't blow themselves up all that often.
     
    eleniel and Louisville Diver like this.
  5. KevinNM

    KevinNM DIR Practitioner

    2,891
    1,384
    113
    High power batteries need a lot of power to recharge at a decent rate. And USB connectors are not suitable for some usage. My primary light has a purpose built charger that connects to exposed metal studs on the light body.

    But batteries sometimes just fail. The series of issues and fires boeing had with the 787 batteries were kind of a demonstration of this. These were highly engineered and carefully built ‘cost is not a problem’ units and still several caught fire.
     
    shoredivr likes this.
  6. rjack321

    rjack321 Captain

    # of Dives: 1,000 - 2,499
    Location: Port Orchard, WA
    9,059
    2,916
    113
    C in lithium ion charging terminology refers to capacity not temperature Celsius. Lithium ion are best charged around 0.5C ie 1/2 of the C rate.

    Charles-Augustin de Coulomb's C-Rate for Batteries

    Charging Lithium-Ion Batteries

    PS most chargers supplied with lithium ion devices have several protection circuits built in to avoid overcharging. In this case, on a 40 year old vessel, there's probably a greater chance of a hidden wiring issue with a smoldering fire going undetected until flashover vs a sudden lithium ion battery explosion. But hopefully we will find that out in time.
     
    wnissen, sunnyboy and eleniel like this.
  7. Compressor

    Compressor ScubaBoard Supporter Staff Member ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: NYS
    2,869
    1,342
    113
    Staff Member Note:

    Please keep the discussion focused; if you want to educate others about topics not related to the accident that has happened, please PM the user you intend to correspond with separately.


    Thank you for your understanding.
     
    DebbyDiver and Allison Finch like this.
  8. DebbyDiver

    DebbyDiver Livin' the dream ScubaBoard Sponsor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: Inland Empire, California
    7,476
    1,000
    113
    I'm neither supporting the dive op, as I don't know them, and not being cavalier. The chances of this happening again are small, and I'm positive that dive ops will increase crew vigilance exponentially.
     
    Buoy_A likes this.
  9. dmaziuk

    dmaziuk Orca

    5,282
    1,801
    113
    Yes, sorry. In the first approximation, roughly, etc. if you fully (dis-)charge a 1 ampere-hour battery in 30 minutes, you have to push in 2 amps -- or out, if you're discharging. This rate will result in much larger temperature build-up in the battery itself, than (dis-)charging the same battery in 2 hours at 0.5A. Heat will shorten the batttery's life and also increase the probability of it going boom in the process.

    What's relevant to the topic is that during charging the energy has to come from somewhere: the boat's generators and/or battery banks need to supply those amps to the outlet the charger's plugged in. Anywhere in between where there's a connection, there can be sparks and heat build-up, not just in the battery itself.
     
    rjack321 and Esprise Me like this.
  10. Esprise Me

    Esprise Me Kelp forest dweller ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Los Angeles, CA
    422
    403
    63
    Lithium batteries with more than 100 watt hours

    I don't think even that much is obvious yet. It may yet turn out that the fire grew so quickly no escape was possible regardless of the state of the exits, or it killed people before they woke up. I would be interested to know how long it takes to evacuate that cabin under various circumstances.
     
Thread Status:
Not open for further replies.

Share This Page