<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_1_1452797066051_2832"><span>Tom,</span></div><div id="yui_3_16_0_1_1452797066051_2788" dir="ltr"><span id="yui_3_16_0_1_1452797066051_2811">I think the relay will be okay, I think I have done it in the past, just can't remember where ;-) </span></div><div id="yui_3_16_0_1_1452797066051_2788" dir="ltr"><span>Hank</span></div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"><font size="2" face="Arial"> On Thursday, January 14, 2016 11:36 AM, TOM WHENT via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br></font></div> <br><br> <div class="y_msg_container"><div id="yiv9361479466"><style type="text/css">#yiv9361479466 p {margin:0;}</style><div><div style="font-family:arial, helvetica, sans-serif;font-size:10pt;color:#000000;">I think that your lead acid battery weight in water question would be a simple matter, but you likely would have to calculate it individually for each size of cell. I would think the density could vary with the composition of each size. Most battery manufacturers provide a spec sheet for their batteries so it would be simple from the weight and dimensions provided to calculate the density and the specific gravity of the cell.<br clear="none"><br clear="none">I have no ideas on the relays being in an oil bath. Would that lead to coking on the contacts?<br clear="none"><br clear="none"><hr id="yiv9361479466zwchr"><div style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica, Arial, sans-serif;font-size:12pt;"><b>From: </b>"hank pronk via Personal_Submersibles" <personal_submersibles@psubs.org><br clear="none"><b>To: </b>"Personal Submersibles General Discussion" <personal_submersibles@psubs.org><br clear="none"><b>Sent: </b>Thursday, January 14, 2016 11:48:28 AM<br clear="none"><b>Subject: </b>[PSUBS-MAILIST] battery compensation<br clear="none"><br clear="none"><div class="yiv9361479466yqt8214485900" id="yiv9361479466yqt08091"><div style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px;"><div dir="ltr" id="yiv9361479466yui_3_16_0_1_1452789352970_2427">Thinking ahead, I need to reduce the weight of my deep diver. I am now planning external batteries- lead acid in oil. This reduces the amount of syntactic foam needed. My deal on CNG tanks fell apart. The ebay seller would not honour the sale, can't blame him. I may go with store bought syntactic foam if business looks good with 30 dollar per barrel oil, Yikes. </div><div dir="ltr" id="yiv9361479466yui_3_16_0_1_1452789352970_2427"><br clear="none"></div><div dir="ltr" id="yiv9361479466yui_3_16_0_1_1452789352970_2427">I am not sure how to go about the oil filled battery set up. I assume the batteries are filled as high as possible with water then topped up with oil, then the compartment filled with oil and a rubber lid on that. I assume you take a syringe with distilled water to top the batteries up from time to time. This way you wouldn't have to drain the oil.</div><div dir="ltr" id="yiv9361479466yui_3_16_0_1_1452789352970_2427">Does anyone know how heavy a battery weighs under water compared to in air?</div><div dir="ltr" id="yiv9361479466yui_3_16_0_1_1452789352970_2427"><br clear="none"></div><div dir="ltr" id="yiv9361479466yui_3_16_0_1_1452789352970_2427">I also am thinking about having the reversing relays for the motors in the oil tank to reduce the amount and size of wires penetrating the hull. I will just send small wires for messaging to the relays.</div><div dir="ltr" id="yiv9361479466yui_3_16_0_1_1452789352970_2427">Hank</div></div></div><br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none">Personal_Submersibles@psubs.org<br clear="none">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<br clear="none"></div><br clear="none"></div></div></div><br><div class="yqt8214485900" id="yqt85115">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div><br><br></div> </div> </div> </div></div></body></html>