<html><head></head><body><div class="ydpe32591a7yahoo-style-wrap" style="font-family:times new roman, new york, times, serif;font-size:16px;"><div id="ydpe32591a7yiv8442100845"><div style="font-family:times new roman, new york, times, serif;font-size:16px;" class="ydpe32591a7yiv8442100845ydpb7099ac9yahoo-style-wrap"><div></div>
<div dir="ltr">Hi Greg,</div><div dir="ltr"><br clear="none"></div><div dir="ltr" data-setdir="false">You must be wrong, says right in the description "Fireproof". :)</div><div dir="ltr"><br clear="none"></div><div dir="ltr">From my research, the top failure methods for Lifepo4 causing a fire is either breaching the container (ie driving a nail through it) or a short circuit across the terminals either by an object or a failed BMS. Other failures can occur by charging or discharging beyond the batteries capacity. Interestingly, the chemical makeup of Lifepo doesn't burn or explode, however it will create so much heat that it initiates combustion in surrounding materials.</div><div dir="ltr"><br></div><div dir="ltr" data-setdir="false">For submarine use, Lifepo are not plug-n-play like wet-cell or AGM. They are more temperamental and require a bit of research to understand and source correctly, require a smart charger of appropriate current and voltage, and a battery management system (BMS) to control everything. The tradeoff is longer power duration and a very large number of recharges before replacement.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Building your own battery bank is a great way to learn how Lifepo works and how to reduce risks associated with them. It also gives you the opportunity to design it for your specific needs and source quality parts.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">All batteries have potential to be very dangerous. Back in the 70's we used to see documentaries showing lead-acid wet cell batteries exploding in cars when jumping them. Whether lifepo is safe for submarine use most likely depends upon how well they've been researched, sourced, and installed for their particular application.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Jon</div><div dir="ltr"><br clear="none"></div><div dir="ltr"><br clear="none"></div><div dir="ltr"><br clear="none"></div><div><br clear="none"></div>
</div><div id="ydpe32591a7yiv8442100845ydp9f8b36adyahoo_quoted_3988920950" class="ydpe32591a7yiv8442100845ydp9f8b36adyahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
</div>
</div></div></div><div id="ydp8ea56b66yiv8442100845yqt75793" class="ydp8ea56b66yiv8442100845yqt9301821561"><div>
On Saturday, July 4, 2026 at 06:10:59 AM EDT, Gregory Snyder via Personal_Submersibles <personal_submersibles@psubs.org> wrote:
</div>
<div><br clear="none"></div>
<div><br clear="none"></div>
<div><div id="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922"><div><div dir="ltr"></div><div dir="ltr">Hi Jon</div><div dir="ltr"><br clear="none"></div><div dir="ltr">It was an Amazon purchase:</div><div dir="ltr"><br clear="none"></div><div dir="ltr"><h1 style="padding:0px;margin:0px;font-family:Arial, sans-serif;line-height:1.2858 !important;color:rgb(86, 89, 89);" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-size-small ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-color-secondary ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-text-normal"><span id="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922title" style="line-height:1.2858 !important;" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-size-small ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-color-secondary">TYKOOL U1-S-400 Group U1 Lithium Lawn Mower Battery,400A 8AH, for John Deere,Cub Cadet,Craftsman Riding Mowers and Tractors,Smart BMS with SOC Display,IP66,V0 Fireproof,Replaces 725-1707D,U1-9 [+ -]</span></h1><div><span style="line-height:1.2858 !important;" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-size-small ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-color-secondary"><br clear="none"></span></div><div><span style="line-height:1.2858 !important;" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-size-small ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-color-secondary">“</span><span style="color:rgb(15, 17, 17);font-family:Arial, sans-serif;background-color:rgb(255, 255, 255);"> Powered by automotive-grade LiFePO4 cells, the TYKOOL S-400 provides over 3,000 deep cycles. It is a cost-effective, long-term power solution that lasts up to 10X longer than traditional AGM batteries.”</span></div><div><span style="color:rgb(15, 17, 17);font-family:Arial, sans-serif;background-color:rgb(255, 255, 255);"><br clear="none"></span></div><div><span style="color:rgb(15, 17, 17);font-family:Arial, sans-serif;background-color:rgb(255, 255, 255);">So I guess it was LiFePO4. </span></div><div><span style="color:rgb(15, 17, 17);font-family:Arial, sans-serif;background-color:rgb(255, 255, 255);"><br clear="none"></span></div><div><span style="line-height:1.2858 !important;" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-size-small ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-color-secondary"><br clear="none"></span></div><div><span style="line-height:1.2858 !important;" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-size-small ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922a-color-secondary"><br clear="none"></span></div></div><div dir="ltr"><br clear="none"><blockquote type="cite">On Jul 2, 2026, at 7:52 PM, Jon Wallace via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br clear="none"><br clear="none"></blockquote></div><blockquote type="cite"><div dir="ltr"><div style="font-family:times new roman, new york, times, serif;font-size:16px;" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydpd932830yahoo-style-wrap"><div></div>
<div dir="ltr">Interesting. Do you know if it was Li-ion or Lifepo4? A number of us have switched to Lifepo4 which are generally much safer than Li-ion.</div><div dir="ltr"><br clear="none"></div><div dir="ltr"><br clear="none"></div><div dir="ltr">Jon</div><div dir="ltr"><br clear="none"></div><div dir="ltr"><br clear="none"></div><div><br clear="none"></div>
</div><div id="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydp7f8c14a3yahoo_quoted_3759724909" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydp7f8c14a3yahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Thursday, July 2, 2026 at 07:33:21 PM EDT, Gregory Snyder via Personal_Submersibles <personal_submersibles@psubs.org> wrote:
</div>
<div><br clear="none"></div>
<div><br clear="none"></div>
<div><div id="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydp7f8c14a3yiv7799157853"><div><div dir="ltr"></div><div dir="ltr">Are lithium batteries safe? </div><div dir="ltr">I bought a lithium battery to use in my John Deere lawn tractor and it burst into flames when I parked it in the garage. Shooting up with billows of nasty smoke. Had I not been right there, it would have burned my garage down for sure. I had a fire extinguisher and was able to stop the bulk of the flames. Scared the crap out of me. </div><div dir="ltr">Not such a fan of lithium all of a sudden. </div><div dir="ltr">Can it be used in subs? </div><div dir="ltr"><br clear="none"></div><div dir="ltr">Best regards</div><div dir="ltr">Greg </div><div dir="ltr"><br clear="none"></div><div dir="ltr"><img alt="image0.jpeg" src="cid:56fedfe9-e99e-b336-cd70-2bf712261b9f@yahoo.com" style="width:100%;max-width:640px;" class="ydp8ea56b66yiv8442100845" data-inlineimagemanipulating="true"><br clear="none"></div><div dir="ltr"><br clear="none"></div><div dir="ltr"><br clear="none"><blockquote type="cite">On Jul 2, 2026, at 12:52 PM, Jon Wallace via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br clear="none"><br clear="none"></blockquote></div><blockquote type="cite"><div dir="ltr"><div style="font-family:times new roman, new york, times, serif;font-size:16px;" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydp7f8c14a3yiv7799157853ydp5ae1b214yahoo-style-wrap"><div></div>
<div dir="ltr">I have not seen a "pack" replacement, but as Alec said, my units came with a generic 8-AA plastic battery holder with a 9-volt type wiring harness. Better off using this and AA lithium batteries that can be recharged via an external charger. Walmart has an 8-pack battery charger for $22.</div><div dir="ltr"><br clear="none"></div><div dir="ltr">Jon</div><div dir="ltr"><br clear="none"></div><div dir="ltr"><br clear="none"></div><div><br clear="none"></div>
</div><div id="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydp7f8c14a3yiv7799157853ydp1567db4ayahoo_quoted_3977213807" class="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydp7f8c14a3yiv7799157853ydp1567db4ayahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Thursday, July 2, 2026 at 01:12:40 PM EDT, Justin Helland via Personal_Submersibles <personal_submersibles@psubs.org> wrote:
</div>
<div><br clear="none"></div>
<div><br clear="none"></div>
<div><div id="ydp8ea56b66yiv8442100845ydp9f8b36adyiv2517169922ydp7f8c14a3yiv7799157853ydp1567db4ayiv9999143455"><div dir="ltr">Greetings! Have any of you found a decent off the shelf battery as a replacement for the OTS 12v NiMH battery in the SSB-2010? I could probably build one with spare cells I have lying around, but I was just wondering if there's anything out there that's cheaper than the $150 OTS wants for the official replacement. </div>
</div><br clear="none"><br clear="none"><br clear="none"><br clear="none">------------------------------------------------------------<br clear="none">You are receiving this email because you are subscribed to the PSUBS.ORG mailing list.<br clear="none"><br clear="none">To unsubscribe from this list:<br clear="none">1) visit <a shape="rect" href="http://psubs.org/mlist" rel="nofollow" target="_blank">http://psubs.org/mlist</a><br clear="none">2) click on "Leave Discussion Group"<br clear="none">3) Follow the provided instructions<br clear="none"><br clear="none">If you have questions about this list, contact:<br clear="none"><a shape="rect" href="mailto:admin@psubs.org" rel="nofollow" target="_blank">admin@psubs.org</a><br clear="none"><br clear="none">PSUBS.ORG Mailing List<br clear="none">PO Box 53<br clear="none">Weare, NH 03281<br clear="none"><br clear="none">----------------------------------<br clear="none"><br clear="none"><br clear="none"><br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" href="mailto:Personal_Submersibles@psubs.org" rel="nofollow" target="_blank">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" rel="nofollow" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div>
</div>
</div><span></span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span>------------------------------------------------------------</span><br clear="none"><span>You are receiving this email because you are subscribed to the PSUBS.ORG mailing list.</span><br clear="none"><span></span><br clear="none"><span>To unsubscribe from this list:</span><br clear="none"><span>1) visit http://psubs.org/mlist</span><br clear="none"><span>2) click on "Leave Discussion Group"</span><br clear="none"><span>3) Follow the provided instructions</span><br clear="none"><span></span><br clear="none"><span>If you have questions about this list, contact:</span><br clear="none"><span>admin@psubs.org</span><br clear="none"><span></span><br clear="none"><span>PSUBS.ORG Mailing List</span><br clear="none"><span>PO Box 53</span><br clear="none"><span>Weare, NH 03281</span><br clear="none"><span></span><br clear="none"><span>----------------------------------</span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span>_______________________________________________</span><br clear="none"><span>Personal_Submersibles mailing list</span><br clear="none"><span>Personal_Submersibles@psubs.org</span><br clear="none"><span>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</span><br clear="none"></div></blockquote></div></div><br clear="none"><br clear="none"><br clear="none"><br clear="none">------------------------------------------------------------<br clear="none">You are receiving this email because you are subscribed to the PSUBS.ORG mailing list.<br clear="none"><br clear="none">To unsubscribe from this list:<br clear="none">1) visit <a shape="rect" href="http://psubs.org/mlist" rel="nofollow" target="_blank">http://psubs.org/mlist</a><br clear="none">2) click on "Leave Discussion Group"<br clear="none">3) Follow the provided instructions<br clear="none"><br clear="none">If you have questions about this list, contact:<br clear="none"><a shape="rect" href="mailto:admin@psubs.org" rel="nofollow" target="_blank">admin@psubs.org</a><br clear="none"><br clear="none">PSUBS.ORG Mailing List<br clear="none">PO Box 53<br clear="none">Weare, NH 03281<br clear="none"><br clear="none">----------------------------------<br clear="none"><br clear="none"><br clear="none"><br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" href="mailto:Personal_Submersibles@psubs.org" rel="nofollow" target="_blank">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" rel="nofollow" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div>
</div>
</div><div><image0.jpeg></div><span></span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span>------------------------------------------------------------</span><br clear="none"><span>You are receiving this email because you are subscribed to the PSUBS.ORG mailing list.</span><br clear="none"><span></span><br clear="none"><span>To unsubscribe from this list:</span><br clear="none"><span>1) visit http://psubs.org/mlist</span><br clear="none"><span>2) click on "Leave Discussion Group"</span><br clear="none"><span>3) Follow the provided instructions</span><br clear="none"><span></span><br clear="none"><span>If you have questions about this list, contact:</span><br clear="none"><span>admin@psubs.org</span><br clear="none"><span></span><br clear="none"><span>PSUBS.ORG Mailing List</span><br clear="none"><span>PO Box 53</span><br clear="none"><span>Weare, NH 03281</span><br clear="none"><span></span><br clear="none"><span>----------------------------------</span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span></span><br clear="none"><span>_______________________________________________</span><br clear="none"><span>Personal_Submersibles mailing list</span><br clear="none"><span>Personal_Submersibles@psubs.org</span><br clear="none"><span>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</span><br clear="none"></div></blockquote></div></div><br clear="none"><br clear="none"><br clear="none"><br clear="none">------------------------------------------------------------<br clear="none">You are receiving this email because you are subscribed to the PSUBS.ORG mailing list.<br clear="none"><br clear="none">To unsubscribe from this list:<br clear="none">1) visit <a shape="rect" href="http://psubs.org/mlist" rel="nofollow" target="_blank">http://psubs.org/mlist</a><br clear="none">2) click on "Leave Discussion Group"<br clear="none">3) Follow the provided instructions<br clear="none"><br clear="none">If you have questions about this list, contact:<br clear="none"><a shape="rect" href="mailto:admin@psubs.org" rel="nofollow" target="_blank">admin@psubs.org</a><br clear="none"><br clear="none">PSUBS.ORG Mailing List<br clear="none">PO Box 53<br clear="none">Weare, NH 03281<br clear="none"><br clear="none">----------------------------------<br clear="none"><br clear="none"><br clear="none"><br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" href="mailto:Personal_Submersibles@psubs.org" rel="nofollow" target="_blank">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" rel="nofollow" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div></div></body></html>