Battery in the Bilge and Exhaust Outlet

[boatpoker]

Originally Posted by Davey1000

I've never seen a ship with a wet exhaust, they usually have funnels! Incidentally wet exhausts and water-lock mufflers have probably killed-off more marine engines than I've had hot dinners. On the other hand a diesel car can be left idle for several years if its a proper diesel without a cam-belt. Years later one just puts a fresh battery on it and it will fire up immediately. No black sludge in the fuel either as all cars (maybe not the Aixam) recirculate the fuel through a filter and water trap. What kills the marine diesel is water evaporating from the water-lock then condensing in the cylinders. If one happens to have a single cylinder engine it is a good idea to store it with the valves closed.

As to batteries in the bilge a friend is doing exactly this at the moment. He has what must have been the heaviest Colvic Springtide in the world as a previous long-dead owner had filled the long keel with concrete and scrap metal to within an inch of the cabin sole. Possibly the previous owner who was Commodore of a sailing club wanted a stiff boat so as not to spill his tea! My friend has bought two enormous batteries each with 1100 amps Cold Cranking Power and the idea is to put them where the ballast was. The batteries are not new however. Allegedly there is a company that services enormous standby generators and every two years as part of the bi-annual service new batteries are fitted whether they are needed or not. The old batteries are then flogged-off to Joe Public. As such batteries could probably belt-out 1500 amps in the summer I bought the bloke a pair of fuse-holders "just in case" as one needs to be very careful with batteries like those.

If he ever gets a big enough charger or alternator to re-charge these batteries he will be generating a huge amount of hydrogen ... hope he has built a method of venting all that hydrogen outside of accommodation spaces.
Hope he's not a smoker

[sailinglegend]

Originally Posted by Kettlewell

.......Aren't some gel and AGM batteries sealed well enough to be submersible?......

My Lifeline AGMs have a 4 psi internal pressure before the valves will blow so there is no way water can get in. They are designed to be able to lie on their side. My small Redflash starter AGM has being lying happily on its side for ten years and still looks new. All my 5 AGMs are in the bilges.

[boatpoker]

I like AGMs but they are not perfect and as much care should be taken with them as any other plastic box full of acid, electricity and hydrogen.