battery relocation

[bomdia]

currently my domestic and engine battteries are stored in the stbd aft lazarette on our hunter legend 375. THis isn't very satifactory for a number of reasons and really i'd like to use the lazarette for other things.
There's a lot of space underneath the bunk in the aft cabin and i was toying with the idea of putting them down there. It would increase the GM, shorten the cables to the starter motor, reducing cable losses; and, as long as there's a vent from that compartment to the outside, I can't think of a eason why not.
Can any of you think why this is a bad idea?
Another plus is that i'd be able to bracket them in properly to stop them shifting in case of a knockdown.
Thanks for your opinions.

 

[cimo]

sounds like solid thinking bomdia.

the aft cabin berth locker is often used as battery location.
you will be moving weight further down the hull (?) which is desirable.
depending on battery weight, you may want to consider hull trim & aim to balance your batteries either side of the centerline.
this may involve an increase to battery lead lenght in some instances - but thats a compromise thats often made.
I would highly recommend straping down your batteries, and as you say venting will have to be provided.
rgds
c

PS - i don't know what GM means?

 

[prv]

Seconded - under aft berths is probably the most common battery location I've found on charter boats, followed by under other berths or seats. So there's no apparent reluctance to fit them in cabin spaces.

I can add another advantage - they'll probably end up drier, and hence with less self-discharge across the top.

Pete

 

[VicS]

"Thirded" then I think

Good idea to strap them down .... I turned one over before I learnt that ...although the Berwick I crewed for years did not have them secured and we sailed that in some pretty rough conditions once or twice.

Interesting about venting. Batteries now all seem to have little vent pipes on them, I think all our car batteries have and so does the leisure battery on the boat but I think if you go back in all cases (Except SHMBO's car which newish anyway) to the previous ones none had the little vent pipes.

Nobody used to worry about venting the batteries or the locker in which they are located and modern batteries probably don't gas as much anyway.

Based on past practices and the lack of incidents due to lack of venting it is one of those things I'd put in the "desirable but not essential" category (along with flame failure devices! )

 

[oldsaltoz]

"Thirded" then I think

Good idea to strap them down .... I turned one over before I learnt that ...although the Berwick I crewed for years did not have them secured and we sailed that in some pretty rough conditions once or twice.

Interesting about venting. Batteries now all seem to have little vent pipes on them, I think all our car batteries have and so does the leisure battery on the boat but I think if you go back in all cases (Except SHMBO's car which newish anyway) to the previous ones none had the little vent pipes.

Nobody used to worry about venting the batteries or the locker in which they are located and modern batteries probably don't gas as much anyway.

Based on past practices and the lack of incidents due to lack of venting it is one of those things I'd put in the "desirable but not essential" category (along with flame failure devices! )

.
We had a half inch hose that ran from the locker to the top of engine air cleaner, it also had a small filter on top of the hose, presumably an attempt to prevent the engine sucking up any fluid, just like a vacuum brake.

Battery compartment (under port aft bunk had no smell at all.

 

[bomdia]

cheers

Thanks for your opinions,
by the way, GM is the distance between the centre of gravity and the yachts Metacentre (hence GM), its the lever that keeps a boat upright, the longer the better (broadly speaking for sailing yachts, until they become too stiff) and if its negative, that's when you become upside down.
I'll get to my battery works.