<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Brian,</div><div>it wasn't easy. You have to maintain the pressure internally between 1 & 6 psi minimum</div><div>to reabsorb gasses. I was doing it to go inside an ambient sub.</div><div>I took the valves off the cells & enclosed the battery. I then put 2 one way 3psi cracking</div><div>pressure valves in the cover. one valve let air in when pressure in the sub was over 3psi</div><div>& the other let air out when the sub ascended & the pressure in the battery was more than</div><div>3 psi above the pressure in the hull. Thus I always maintained a minimum internal pressure</div><div>of 3psi. It was filled with mineral oil.</div><div>I believe deep sea power & lights oil filled sea battery is AGM. The diaphragm that covers it would keep some internal pressure in the battery.</div><div>Alan</div><div> </div><div><br><br>Sent from my iPad</div><div><br>On 16/01/2016, at 3:25 pm, Brian Cox via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div style="font-family:Arial, sans-serif; font-size:10pt;"><div>Alan, I thought you indicated that it's not good to compensate the AGM's because they can't vary over 6 psi ?</div><div> </div><div>Brian<br><br>--- <a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a> wrote:<br><br>From: Alan via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>To: Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>Subject: Re: [PSUBS-MAILIST] battery compensation<br>Date: Sat, 16 Jan 2016 09:46:38 +1300<br><br></div><div>I am not sure Brian,</div><div>they give off very little gas. Certainly a lot less than wet cel batteries.</div><div>Mainly the gas is given off during</div><div>charging & in particular if the charging is not done right.</div><div>On my AGMs there is a glued on cover plate running across the</div><div>tops of all the valves to hold them in place. The valves themselves</div><div>are just a flexible cap. Any overpressure above a couple of psi just</div><div>forces out the side of the flexible cap. </div><div>I compensated mine with mineral oil, but used the scented baby oil </div><div>from the supermarket. The chemicals in the scented mineral oil</div><div>caused it to off gas more than normal. When I changed to unscented</div><div>it stopped, but even then it wasn't excessive.</div><div>Alan<br><br>Sent from my iPad</div><div><br>On 16/01/2016, at 7:57 am, Brian Cox via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote><div><div style="font-family: Arial, sans-serif; font-size: 10pt;"><div>Alan,</div><div> I wouldn't mind knowing the workings of those AGM's since I will be using them inside my cabin. Should I have a hydrogen monitor?</div><div> </div><div>Brian Cox<br><br>--- <a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a> wrote:<br><br>From: Alan via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>To: Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>Subject: Re: [PSUBS-MAILIST] battery compensation<br>Date: Sat, 16 Jan 2016 07:49:25 +1300<br><br></div><div>Hi Brian,</div><div>the AGM batteries need to be kept at an internal pressure</div><div>of between 1-6 psi to reabsorb gasses. They have little one</div><div>way valves on each cell & are difficult to compensate.</div><div>Can go in to detail if you like.</div><div>Alan<br><br>Sent from my iPad</div><div><br>On 16/01/2016, at 6:01 am, Brian Cox via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote><div><div style="font-family: Arial, sans-serif; font-size: 10pt;"><div>Hank,</div><div> Using AGM batteries you may have less issues with topping off the cells.</div><div> </div><div>Brian<br><br>--- <a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a> wrote:<br><br>From: hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>To: Personal Submersibles General Discussion <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br>Subject: Re: [PSUBS-MAILIST] battery compensation<br>Date: Thu, 14 Jan 2016 18:47:38 +0000 (UTC)<br><br></div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px; background-color: rgb(255, 255, 255);"><div><span>Tom,</span></div><div dir="ltr"><span>I think the relay will be okay, I think I have done it in the past, just can't remember where ;-) </span></div><div dir="ltr"><span>Hank</span></div> <div><br><br></div><div 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 face="Arial" size="2"> On Thursday, January 14, 2016 11:36 AM, TOM WHENT via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br></font></div> <br><br> <div><div><div><div style="color: rgb(0, 0, 0); font-family: arial, helvetica, sans-serif; font-size: 10pt;">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><br>I have no ideas on the relays being in an oil bath. Would that lead to coking on the contacts?<br><br><hr><div style="color: rgb(0, 0, 0); font-family: Helvetica, Arial, sans-serif; font-size: 12pt; font-style: normal; font-weight: normal; text-decoration: none;"><b>From: </b>"hank pronk via Personal_Submersibles" <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br><b>To: </b>"Personal Submersibles General Discussion" <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br><b>Sent: </b>Thursday, January 14, 2016 11:48:28 AM<br><b>Subject: </b>[PSUBS-MAILIST] battery compensation<br><br><div><div style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px; background-color: rgb(255, 255, 255);"><div dir="ltr">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"><br></div><div dir="ltr">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">Does anyone know how heavy a battery weighs under water compared to in air?</div><div dir="ltr"><br></div><div dir="ltr">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">Hank</div></div></div><br>_______________________________________________<br>Personal_Submersibles mailing list<br><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br></div><br></div></div></div><br><div>_______________________________________________<br>Personal_Submersibles mailing list<br><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br></div><br><br></div> </div> </div> </div></div>_______________________________________________
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