Captain Nemo wrote:
As of three months ago, Hydrocaps were still available. I came across them while buying something else for the sub. If I remember where I saw 'em, I'll post the URL. They work good, and are economical too. If you're carrying L-A batteries inside the hull with you, they make real good sense, IMOHO. My batts are inside the p-hull with me. This overhaul, I switched from 24 volts to a 36-volt (three 12's) battery pack, and a seperate battery for the incidental electrical systems: lights, fans, 'finder, PA, U-phone, etc. I decided to go with sealed OPTIMA gel-cel batteries for a few reasons. 1. Deep Cycle / High cranking amps / good endurance: well suited to my new M-K Riptide 101. 2. No fumes and no servicing at all. Nothing. Zip. Nada. Take 'em to bed and sleep with 'em if you wanna. Totally clean and very user friendly. 3. Operates at any angle or attitude. This time around, modifications and design requirements in the NAUTILUS MINISUB mean the systems battery has to be mounted on it's side in a metal box I built and installed up in the nose cone. Weight-and-balancewise, that's where it needs to be; and it's gotta be sideways to fit all the other electrical components in up there with it, too. So I've got to mount this one on it's side, and the OPTIMA does that. 4. Also, we're going to be making use of my hydrobatic ballast system, standing the sub 90-degrees on it's tail and submerging on ballast as in the last scene of 20,000 LEAGUES UNDER THE SEA when we film for a TV show this Summer. To do that, I can't use a propulsion battery pack that will leak electrolyte when placed at an extreme unusual attitude; so the OPTIMA fills the bill. I talked to the salesman and read the brochure: these can even be mounted upside down and will still work fine: no problem at all. 5. High resistance to damage. Depending on circumstances, something could bang the battery case, and an acid spill inside a pressure hull would be a drag. The OPTIMA case structure, gel, and "plates" (if that's the right word: the innards don't look like regular plates) are said to be pretty well indestructable: able to sustain severe damage without leaking or failing to provide power. So for my own special purposes, this OPTIMA sealed battery is pretty much "necessary". But even if you plan to stay "pointy end forward and dirty side down" all the time, the fact that they don't leak fluids or gas might have some appeal for you, too. The drawback is they are expensive. I guess that comes down to what money is worth to you, and how badly you want or need this kind of system for your sub. I'm not trying to sell 'em; just thought I'd mention them in case anyone might be looking for an alternative to regular Lead - Acid batteries. Pat