Batteries location for an electric propelled boat ?

[Externet]

Hi.

For a flat bottomed or for a mild V hull; where is more convenient to install a dozen of lead-acid batteries, to obtain the best stability ?

 

As low as possible of course, but in two rows along the sides or a single row above the keel line ?

[Greg H.]

I don't think it matters as long as the weight is distributed evenly across both sides of the center line to prevent listing.

Though I will add that you want to make sure the batteries don't add so much weight that the boat swamps when you launch it.

[imatfaal]

You need to look at the vertical separation between the centre of buoyancy and the centre of mass - but you definitely want then in the same longitudinal plane. I think the ideal vertical separation varies dependent on how agile / stable you want your craft; in an analogous manner to angle of anhedral / dehedral in aeroplanes - real manoeuvrability requires you to do away with negative feedback (and possibly introduce positive). The forward aft separation would allow an automatic angle of trim - normally trimmed such that propeller is submerged whilst the bow is slightly higher in the water

[arc]

There is a sweet spot in all boats where the cargo (human or other) can receive the least amount of vibration and shock. It is almost always directly forward the stern or transom. That is the pivot point of the dynamic loading caused by waves. The farther forward you go the more vertical movement is produce. The pounding from a series of large waves can fracture what would seem as normally durable components.

 

Your batteries are I assume lead acid, which are vulnerable to vibrations and shock. They are best given a home down low as far back as possible, unless its nothing but smooth water then go for stability and trim.

 

How big of boat?

 

 

Oh, and I forgot to mention, if lead acid ventilate well. Wave action + hydrogen gas + spark from loose wire = BIG BANG acid shower.

Edited September 15, 2013 by arc