[PSUBS-MAILIST] Pressure resistant lie batteries

Tue Dec 3 19:12:37 EST 2019

The cells are simple, the BMS is the complicated part.
For a pressure-tolerant battery, you would either need to house
off-the-shelf BMS electronics in the pressure hull, or in a separate
pressure-housings.

There are commercially available, pressure-tolerant lithium-polymer
batteries, and they all use pouch-style cells. Alan, you've correctly
deduced that the cylindrical cells don't hold up.

Lithium Iron Phosphate cells are safe enough, that I would consider putting
them inside of the pressure hull. They don't use a flammable or pyrophoric
electrolyte like Lithium Polymer, so won't burst into flames if punctured,
or overloaded. They also don't off gas hydrogen like lead acid (And yes,
even AGM's can and do offgas hydrogen) or have acid that can spill or boil
over.

A 12V or 24V LiFePO4 battery string would be the ideal candidate for
installation in a K250. Probably on the whole safer than lead-acid,
lighter, and would be able to be charged much quicker, practically a
lunch-break.

-River J. Dolfi
rdolfi7 at gmail.com

On Tue, Dec 3, 2019 at 2:42 PM via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

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> Today's Topics:
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>    1. PanelPilotACE (Pete Niedermayr via Personal_Submersibles)
>    2. Re: PanelPilotACE (Alan via Personal_Submersibles)
>    3. Pressure resistant lie batteries
>       (Beram Mahmoud via Personal_Submersibles)
>    4. Triton sub cabin fire (March 2019)
>       (irox via Personal_Submersibles)
>    5. Re: Pressure resistant lie batteries
>       (Alan via Personal_Submersibles)
>    6. Re: Pressure resistant lie batteries
>       (Alan via Personal_Submersibles)
>
>
> ----------------------------------------------------------------------
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> Message: 1
> Date: Tue, 19 Nov 2019 00:07:17 +0000 (UTC)
> From: Pete Niedermayr via Personal_Submersibles
>         <personal_submersibles at psubs.org>
> To: "personal_submersibles at psubs.org"
>         <personal_submersibles at psubs.org>
> Subject: [PSUBS-MAILIST] PanelPilotACE
> Message-ID: <1384623172.2927077.1574122037541 at mail.yahoo.com>
> Content-Type: text/plain; charset="utf-8"
>
> Just saw this on SV Seeker
> PanelPilotACE PanelPilot Displays - Lascar Electronics
>
> |
> |
> |  |
> PanelPilotACE PanelPilot Displays - Lascar Electronics
>
>
>  |
>
>  |
>
>  |
>
>
>
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> Message: 2
> Date: Tue, 19 Nov 2019 13:32:30 +1300
> From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
> To: Personal Submersibles General Discussion
>         <personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] PanelPilotACE
> Message-ID: <3E8BF536-891A-4110-8A76-79170BE781A6 at yahoo.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Looks a great product Pete, & cheap.
> No writing of code!
> This video gives a good explanation of it.
> https://m.youtube.com/watch?v=EV_m3dcdRc8&t=
> Alan
>
> > On 19/11/2019, at 1:07 PM, Pete Niedermayr via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
> >
> > Just saw this on SV Seeker
> >
> > PanelPilotACE PanelPilot Displays - Lascar Electronics
> >
> > PanelPilotACE PanelPilot Displays - Lascar Electronics
> >
> >
> > _______________________________________________
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> Message: 3
> Date: Tue, 3 Dec 2019 19:02:02 +0100
> From: Beram Mahmoud via Personal_Submersibles
>         <personal_submersibles at psubs.org>
> To: Personal Submersibles General Discussion
>         <personal_submersibles at psubs.org>
> Subject: [PSUBS-MAILIST] Pressure resistant lie batteries
> Message-ID: <98C084E6-EBDC-4057-A4ED-719158070DBD at gmx.de>
> Content-Type: text/plain;       charset=us-ascii
>
> Hello,
> Does anyone know of an instruction how to make pressure resistant li
> batterie systems?
>
> Is it sufficient to fill up the battery with the bms in an oil filled
> canister?
>
> Best regards
> Beram
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 3 Dec 2019 11:03:54 -0800 (GMT-08:00)
> From: irox via Personal_Submersibles <personal_submersibles at psubs.org>
> To: personal_submersibles at psubs.org
> Subject: [PSUBS-MAILIST] Triton sub cabin fire (March 2019)
> Message-ID:
>         <2116245540.6634.1575399835653 at wamui-agami.atl.sa.earthlink.net>
> Content-Type: text/plain; charset=UTF-8
>
>
> I came cross this article about a cabin fire in what I believe is a Triton
> sub:
>
> https://www.businessinsider.com/british-research-sub-surfaces-after-fire-300-feet-below-india-ocean-2019-3
>
> Does anybody have more details on this incident?
>
> The article is a bit light on details, although the fact it took 23
> minutes to do an emergency ascent from 100meters/330feet to the surface is
> worth noting.  That seems like a long time.
>
> Thanks,
>  Ian.
>
>
> ------------------------------
>
> Message: 5
> Date: Wed, 4 Dec 2019 11:35:54 +1300
> From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
> To: Personal Submersibles General Discussion
>         <personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] Pressure resistant lie batteries
> Message-ID: <DC0C46BA-0B7C-4141-8B0C-49A1325D1FA9 at yahoo.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Hi Beram,
> there is a firm that makes lithium battery packs for underwater use.
> https://www.swe.com/
> What depth do you want them to go down to? How big a battery pack?
> I have cut open lithium iron & lithium polymer batteries & they look
> pretty pressure resistant. The lithium polymer with the soft flat packs
> look
> like they might take the pressure better than the Lithium iron in the
> cylindrical
> form. The latter having a hard case that might crush & damage the battery.
> I am not sure about lithium phosphate which is the preferred option for
> safety.
> I have a 48V 40Ah lithium phosphate battery that I run an inflatable on.
> What complicates matters is the wires coming from each cel for balance
> charging. I am not sure how you handle this. Perhaps encapsulate the
> balance
> charging electronics & leave it in the battery enclosure.
> Alan
>
>
>
> > On 4/12/2019, at 7:02 AM, Beram Mahmoud via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
> >
> > Hello,
> > Does anyone know of an instruction how to make pressure resistant li
> batterie systems?
> >
> > Is it sufficient to fill up the battery with the bms in an oil filled
> canister?
> >
> > Best regards
> > Beram
> >
> > _______________________________________________
> > Personal_Submersibles mailing list
> > Personal_Submersibles at psubs.org
> > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
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> ------------------------------
>
> Message: 6
> Date: Wed, 4 Dec 2019 11:41:29 +1300
> From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
> To: Personal Submersibles General Discussion
>         <personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] Pressure resistant lie batteries
> Message-ID: <4336E505-98F7-4B0C-95F7-23097A268047 at yahoo.com>
> Content-Type: text/plain;       charset=us-ascii
>
> Beram,
> additionally, a lot of the balance charging electronic boards have large
> electrolytic
> capacitors & if you just stick them in oil they may collapse under
> pressure.
> Alan
>
> > On 4/12/2019, at 7:02 AM, Beram Mahmoud via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
> >
> > Hello,
> > Does anyone know of an instruction how to make pressure resistant li
> batterie systems?
> >
> > Is it sufficient to fill up the battery with the bms in an oil filled
> canister?
> >
> > Best regards
> > Beram
> >
> > _______________________________________________
> > Personal_Submersibles mailing list
> > Personal_Submersibles at psubs.org
> > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
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