<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr"><meta http-equiv="content-type" content="text/html; charset=utf-8">Hank,<div>Nuytco switched to LiFePo4 several years ago; Phil said it was a “no-brainer” since the life span, charge cycles, energy density, etc. actually make them cheaper in the long run. In comparing capacity, remember that you can only discharge an AGM down to 50% or so without significant damage, whereas you can take Li down to 10%. The numbers can be misleading unless you make the proper adjustments in order to make an apples to apples comparison. Taking into account space and fit considerations, here is a size chart:</div><div><div class="iKJnec" aria-level="3" role="heading" style="font-size: 16px; -webkit-text-size-adjust: auto; margin-bottom: 16px; caret-color: rgb(32, 33, 36); color: rgb(32, 33, 36); font-family: arial, sans-serif;"><br></div><div class="iKJnec" aria-level="3" role="heading" style="font-size: 16px; -webkit-text-size-adjust: auto; margin-bottom: 16px; caret-color: rgb(32, 33, 36); color: rgb(32, 33, 36); font-family: arial, sans-serif;">BCI Battery Group Size Chart</div><div class="webanswers-webanswers_table__webanswers-table" style="-webkit-text-size-adjust: auto; overflow: hidden; position: relative; padding-top: 0px; padding-bottom: 20px; caret-color: rgb(32, 33, 36); color: rgb(32, 33, 36); font-family: arial, sans-serif; font-size: 14px;"><table style="table-layout: fixed; width: 620px; border-collapse: collapse;"><tbody><tr class="ztXv9" style="border-bottom-width: 1px; border-bottom-style: solid; border-bottom-color: rgb(235, 235, 235);"><th style="word-wrap: normal; height: 26px; padding: 8px 10px 8px 0px; font-weight: bolder; vertical-align: top;"><b>Group Size</b></th><th style="word-wrap: normal; height: 26px; padding: 8px 10px; font-weight: bolder; vertical-align: top;">LxWxH (inches)</th><th style="word-wrap: normal; height: 26px; padding: 8px 10px; font-weight: bolder; vertical-align: top;">LxWxH (cm)</th></tr><tr style="border-bottom-width: 1px; border-bottom-style: solid; border-bottom-color: rgb(235, 235, 235);"><td style="word-wrap: normal; height: 26px; padding: 8px 10px 8px 0px;"><b>Group</b> 24 <b>Batteries</b></td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">10.25 x 6.8125 x 8.875</td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">26 x 17.3 x 22.5</td></tr><tr style="border-bottom-width: 1px; border-bottom-style: solid; border-bottom-color: rgb(235, 235, 235);"><td style="word-wrap: normal; height: 26px; padding: 8px 10px 8px 0px;"><b>Group</b> 27 <b>Batteries</b></td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">12.0625 x 6.8125 x 8.875</td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">30.6 x 17.3 x 22.5</td></tr><tr style="border-bottom-width: 1px; border-bottom-style: solid; border-bottom-color: rgb(235, 235, 235);"><td style="word-wrap: normal; height: 26px; padding: 8px 10px 8px 0px;"><b>Group</b> 31 <b>Batteries</b></td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">13 x 6.8125 x 9.4375</td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">33 x 17.3 x 24</td></tr><tr style="border-bottom-width: 1px; border-bottom-style: solid; border-bottom-color: rgb(235, 235, 235);"><td style="word-wrap: normal; height: 26px; padding: 8px 10px 8px 0px;"><b>Group</b> 34 <b>Batteries</b></td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">10.25 x 6.8125 x 7.875</td><td style="word-wrap: normal; height: 26px; padding: 8px 10px;">26 x 17.3 x 20</td></tr></tbody></table></div>More info is available at www.batteryequivalents.com </div><div><br></div><div>The fail point inside Li batteries seems to be the Battery Management System (BMS). On the cheaper batteries, the terminals, buss bars, and wiring are often under-sized. For a non-sub application my choice is Battle Born. They are a little more expensive than other 100 amp hour batteries in their class (about $950), but the construction and quality is certainly superior. www.battlebornbatteries.com</div><div>They have some good videos including on on designing and sizing battery banks. </div><div>I’ll have to take a closer look at the info Cliff provided.</div><div><br></div><div>On a related subject (again for a non-sub application), I started with a Bluetti AC200 all-in-one which includes Battery bank, a 2000W pure sine wave inverter and six 120v outlets. </div><div><br></div><div>You can get a lot of good info on YouTube by searching Will Prowse. It’ll be interesting to see what you come up with.</div><div><br></div><div>Cheers,</div><div>Jim</div><div><br></div><div><br></div><div><br></div><div><br><div dir="ltr">Sent from my iPad</div><div dir="ltr"><br><blockquote type="cite">On Oct 19, 2020, at 9:42 AM, Cliff Redus via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><!--[if gte mso 9]><xml><o:OfficeDocumentSettings><o:AllowPNG/><o:PixelsPerInch>96</o:PixelsPerInch></o:OfficeDocumentSettings></xml><![endif]--><div class="ydp9c9d756yahoo-style-wrap" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><div style="font-family: times new roman, new york, times, serif; font-size: 16px;"></div>
<div dir="ltr" data-setdir="false" style="">Hank, I have been doing a lot of research on this vary issue with my new boat, the R800. I really like the Valence U27-12xp lithium <span><span style="color: rgb(0, 0, 0); font-family: times new roman, new york, times, serif; font-size: 16px;">Li FePO4 </span></span>battery. There is a least one commercial private sub that uses these battery modules. Do a search on YouTube for info/ teardowns on these batteries. What is good about them is battery chemistry is more stable than conventional LI batteries and heavy duty electronics. Not your typical crappy Chinese electronics. They come in a group 27 form factor with a nominal 12V with a built in BMS in each module. Each module has a 137AH capacity.<br></div><div dir="ltr" data-setdir="false" style="">These modules new are on the order of $2,500 each but are readily available on Ebay at $450 each. Each module has a life of 3000-4000 cycles with used modules on Ebay with 10-300 cycles so lots of life left in them. They are set up so that an overall BMS unit manages the entire pack interfacing with each modules interval BMS. These modules can be configured in just about any series/parallel arrangement you can think. For my boat, I am looking at 3S2P configuration, that is, 3 of these U27-12XP's in series with 2 banks, one in each pod in parallel. This would give a bank voltage of 36V and a bank capacity of 274AH or 9.9kWh. I am using 36V the main propulsion bank to mate with the Minn Kota 101 running at 36V nominal. IF you want more capacity, you would put more more in parallel, i.e., 3SnP where n=1, 2... I am also using these for the emergecy battery bank with a 0S2P configuration for 24V nominal.</div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;">Communication with module and cells within each module is via. serial communication using RS-485. After a bank has been wired, you can connect a laptop an plug into the overall BMS and integrated each module on aspects such as number of cycles, cell voltage and temperature, current ...</div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;">For PLC guys, because it uses standard RS-485 serial communication, the PLC can also interface with any are all of the modules. See for a quick overview.</div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><a href="https://www.youtube.com/watch?v=rRh2PVWRnsI" rel="nofollow" target="_blank" class="enhancr_card_3331105464">Valence U-Charge XP Series Lithium Ion Batteries</a><br></div><div style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div><div id="ydp28340c8benhancr_card_3331105464" class="ydp28340c8byahoo-link-enhancr-card ydp28340c8bymail-preserve-class ydp28340c8bymail-preserve-style" style="font-family: YahooSans, Helvetica Neue, Segoe UI, Helvetica, Arial, sans-serif; font-size: 16px; max-width: 400px;" data-url="https://www.youtube.com/watch?v=rRh2PVWRnsI" data-embed-url="https://www.youtube.com/embed/rRh2PVWRnsI?feature=oembed" data-type="YENHANCER" data-size="MEDIUM" contenteditable="false"><a href="https://www.youtube.com/watch?v=rRh2PVWRnsI" style="text-decoration:none !important;color:#000 !important" class="ydp28340c8byahoo-enhancr-cardlink" rel="nofollow" target="_blank"><table border="0" class="ydp28340c8bcard-wrapper ydp28340c8byahoo-ignore-table" cellpadding="0" cellspacing="0" style="max-width:400px"><tbody><tr><td width="400"><table border="0" class="ydp28340c8bcard ydp28340c8byahoo-ignore-table" cellpadding="0" cellspacing="0" width="100%" style="max-width:400px;border-width:1px;border-style:solid;border-color:rgb(224, 228, 233);border-radius:2px"><tbody><tr><td class="ydp28340c8bcard-primary-image-cell" background="https://s.yimg.com/lo/api/res/1.2/jrT7vKseZX.JH4hMJ.8oMw--~A/Zmk9ZmlsbDt3PTQwMDtoPTIwMDthcHBpZD1pZXh0cmFjdA--/https://i.ytimg.com/vi/rRh2PVWRnsI/hqdefault.jpg.cf.jpg" bgcolor="#000000" valign="top" height="175" style="background-color: rgb(0, 0, 0); background-size: cover; position: relative; border-radius: 2px 2px 0px 0px; min-height: 175px;"><!--[if gte mso 9]><v:rect fill="true" stroke="false" style="width:396px;height:175px;position:absolute;top:0;left:0;"><v:fill type="frame" color="#000000" src="https://s.yimg.com/lo/api/res/1.2/jrT7vKseZX.JH4hMJ.8oMw--~A/Zmk9ZmlsbDt3PTQwMDtoPTIwMDthcHBpZD1pZXh0cmFjdA--/https://i.ytimg.com/vi/rRh2PVWRnsI/hqdefault.jpg.cf.jpg"/></v:rect><![endif]--><table border="0" class="ydp28340c8bcard-overlay-container-table ydp28340c8byahoo-ignore-table" cellpadding="0" cellspacing="0" style="width:100%"><tbody><tr><td class="ydp28340c8bcard-overlay-cell" background="https://s.yimg.com/cv/ae/nq/storm/assets/enhancrV21/1/enhancr_gradient-400x175.png" bgcolor="transparent" valign="top" style="background-color: transparent; border-radius: 2px 2px 0px 0px; min-height: 175px;"><!--[if gte mso 9]><v:rect fill="true" stroke="false" style="width:396px;height:175px;position:absolute;top:-18px;left:0;"><v:fill type="pattern" color="#000000" src="https://s.yimg.com/cv/ae/nq/storm/assets/enhancrV21/1/enhancr_gradient-400x175.png"/><v:textbox inset="0,0,20px,0"><![endif]--><table border="0" class="ydp28340c8byahoo-ignore-table" height="175" style="width: 100%; min-height: 175px;"><tbody><tr><td class="ydp28340c8bcard-richInfo2" style="text-align:left;padding:15px 0 0 15px;vertical-align:top"></td><td class="ydp28340c8bcard-actions" style="text-align:right;padding:15px 15px 0 0;vertical-align:top"><div class="ydp28340c8bcard-share-container"></div></td></tr></tbody></table><!--[if gte mso 9]></v:textbox></v:rect><![endif]--></td></tr></tbody></table></td></tr><tr><td><table border="0" align="center" class="ydp28340c8bcard-info ydp28340c8byahoo-ignore-table" cellpadding="0" cellspacing="0" style="background:#fff;position:relative;z-index:2;width:100%;max-width:400px;border-radius:0 0 2px 2px;border-top:1px solid rgb(224, 228, 233)"><tbody><tr><td style="background-color:#ffffff;padding:16px 0 16px 12px;vertical-align:top;border-radius:0 0 0 2px"><img class="ydp28340c8bcard-object-1 ydp28340c8byahoo-ignore-inline-image ydp28340c8bymail-preserve-class" src="https://s.yimg.com/nq/storm/assets/enhancrV2/23/logos/youtube.png" height="36" style="min-width:36px;margin-top:3px" data-unique-identifier=""></td><td style="vertical-align:middle;padding:12px 24px 16px 12px;width:99%;font-family:YahooSans, Helvetica Neue, Segoe UI, Helvetica, Arial, sans-serif;border-radius:0 0 2px 0"><h2 class="ydp28340c8bcard-title" style="font-size: 14px; line-height: 19px; margin: 0px 0px 6px; font-family: YahooSans, Helvetica Neue, Segoe UI, Helvetica, Arial, sans-serif; color: rgb(38, 40, 42); max-width: 314px;">Valence U-Charge XP Series Lithium Ion Batteries</h2><p class="ydp28340c8bcard-description" style="font-size: 12px; line-height: 16px; margin: 0px; color: rgb(151, 155, 167);"></p></td></tr></tbody></table></td></tr></tbody></table></td></tr></tbody></table></a></div><div style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;">On the downside of LI, it would be good to hear from Hugh Fulton, designer of the Q-Sub in New Zealand. The last time I spoke with Hugh he said that he was on his third set of LI batteries and was not a happy camper on the battery front. </div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;">As a comparison, below is a table of the Valence U27-XP compared with a Mighty Max ML110-12 AGM.</div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><div></div><div><table border="0" cellpadding="0" cellspacing="0" width="386" style="border-collapse: collapse;width:290pt">
<colgroup><col width="181" style="mso-width-source:userset;mso-width-alt:6619;width:136pt">
<col width="102" style="mso-width-source:userset;mso-width-alt:3730;width:77pt">
<col width="103" style="mso-width-source:userset;mso-width-alt:3766;width:77pt">
</colgroup><tbody><tr height="20" style="min-height: 15pt;">
<td height="20" class="ydp8b639aeaxl66" colspan="3" width="386" style="width: 290pt; min-height: 15pt;">Comparison - Valence U27-12XP and MightMax ML110-12</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;"></td>
<td class="ydp8b639aeaxl65"></td>
<td class="ydp8b639aeaxl65"></td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" class="ydp8b639aeaxl66" style="min-height: 15pt;">Description</td>
<td class="ydp8b639aeaxl67">U27-12XP</td>
<td class="ydp8b639aeaxl67">ML110-12</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Configuration</td>
<td class="ydp8b639aeaxl65">3S2P</td>
<td class="ydp8b639aeaxl65">3S2P</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Type</td>
<td class="ydp8b639aeaxl65">Li FePO4</td>
<td class="ydp8b639aeaxl65">AGM</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Group</td>
<td class="ydp8b639aeaxl65">27</td>
<td class="ydp8b639aeaxl65">30H</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Bank Voltage</td>
<td class="ydp8b639aeaxl65">36V</td>
<td class="ydp8b639aeaxl65">36V</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Capacity</td>
<td class="ydp8b639aeaxl65">276</td>
<td class="ydp8b639aeaxl65">220</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Watt Hours</td>
<td class="ydp8b639aeaxl65">9.9</td>
<td class="ydp8b639aeaxl65">7.9</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Max Discharge current</td>
<td class="ydp8b639aeaxl65">150A</td>
<td class="ydp8b639aeaxl65">900A</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Bank Cost (6 modules)</td>
<td class="ydp8b639aeaxl65">$2,700 used</td>
<td class="ydp8b639aeaxl65">$1,212 new</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Cycles</td>
<td class="ydp8b639aeaxl65">4000</td>
<td class="ydp8b639aeaxl65">500</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Weight (Lbs)</td>
<td class="ydp8b639aeaxl65">42.2</td>
<td class="ydp8b639aeaxl65">63.9</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Requires BMS</td>
<td class="ydp8b639aeaxl65">Yes</td>
<td class="ydp8b639aeaxl65">No</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Detailed cell sensors</td>
<td class="ydp8b639aeaxl65">YEs</td>
<td class="ydp8b639aeaxl65">No</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">SOC measurement</td>
<td class="ydp8b639aeaxl65">Yes</td>
<td class="ydp8b639aeaxl65">No</td>
</tr>
<tr height="20" style="min-height: 15pt;">
<td height="20" style="min-height: 15pt;">Interface with PLC via RS485</td>
<td class="ydp8b639aeaxl65">Yes</td>
<td class="ydp8b639aeaxl65">No</td>
</tr></tbody></table></div><br></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;">For a shallow diving psub, the advantage of LI energy density as compared with AGM is not that important as we normally add lots of ballast but for a deep diver, you normally have much less ballast due to the added thickness of steel in the hull so the energy density becomes a very big advantage. For the comparison above you can see the weight of the <span><span style="color: rgb(0, 0, 0); font-family: times new roman, new york, times, serif; font-size: 16px;">U27-12XP is 34% less than the <span><span style="color: rgb(0, 0, 0); font-family: times new roman, new york, times, serif; font-size: 16px;">ML110-12 AGM.</span></span></span></span></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: times new roman, new york, times, serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: times new roman, new york, times, serif; font-size: 16px;"><br></span></span></span></span></div><div dir="ltr" data-setdir="false" style="">Let me know what you finally end up with. I am assuming this is for the E3000?</div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: times new roman, new york, times, serif; font-size: 16px;"><span><span style="color: rgb(0, 0, 0); font-family: times new roman, new york, times, serif; font-size: 16px;"><br></span></span></span></span></div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;">Cliff</div><div dir="ltr" data-setdir="false" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><br></div>
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On Monday, October 19, 2020, 07:22:26 AM CDT, hank pronk via Personal_Submersibles <personal_submersibles@psubs.org> wrote:
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<div><div id="ydpc2a684a5yiv8791090027"><div><div class="ydpc2a684a5yiv8791090027yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr">Hi All,</div><div dir="ltr">I am looking at going with Lithium batteries inside my sub. Of coarse weight is the reason. Has anyone gone down this road?</div><div dir="ltr">What is best?</div><div dir="ltr">Hank</div></div></div></div>_______________________________________________<br>Personal_Submersibles mailing list<br><a href="mailto:Personal_Submersibles@psubs.org" rel="nofollow" target="_blank">Personal_Submersibles@psubs.org</a><br><a 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></div>
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