<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_1452789352970_2427" 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 id="yui_3_16_0_1_1452789352970_2427" dir="ltr"><br></div><div id="yui_3_16_0_1_1452789352970_2427" 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 id="yui_3_16_0_1_1452789352970_2427" dir="ltr">Does anyone know how heavy a battery weighs under water compared to in air?</div><div id="yui_3_16_0_1_1452789352970_2427" dir="ltr"><br></div><div id="yui_3_16_0_1_1452789352970_2427" 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 id="yui_3_16_0_1_1452789352970_2427" dir="ltr">Hank</div></div></body></html>