Replacing the battery box

[Snboard976]

I need to expand my current battery box. My idea for a new battery box looks two partial bulkheads with steps cut into it. I will tab two partial bulkheads to the hull and build shelves for the batteries between the two bulkheads. The end product will look like a staircase. Batteries 1 and 2 will go on the lowest step. Battery 3 will go on the second step in line with the first two and battery 4 will go on step two, but aft of battery 3.

My question is how should I tab the bulkheads to the hull? Should the plywood fit snuggly against the hull? I have heard that I should leave a gap so there are no pressure points against the hull. If I do need to leave a gap, how big should the gap be and how do I hold the box in the correct position while I am tabbing? Is there a filler I should apply to the bottom of the partial bulkheads before I tab them? Any ideas, tips or advice would be appreciated. Thank You.

[Randy]

Why don't you just place them in the bilge area forward of the v-drive? A lot simplier and will keep weight lower and centered in the hull.

[Snboard976]

That's a good idea.  I think I saw a picture of that type of installation on seadragon's site.  I will check the fit next weekend.  How would I keep the batteries from sliding when the boat heals.

[RayNWanda]

You can glass in a couple of pieces  of aluminum angle. You can either make a battery tray to fit between or set battery boxes and strap to the aluminum angle. Remember to drill holes in the aluminum and pull some yarns of roving through them. Fiberglass won't stick to the aluminum, but the yarns will give it something to work with.

[slokat]

I have (4) 6v trojans mounted in the port sail locker in a tabbed plywood enclosure: http://slokat.com/Wind%20Tamer/pics/DSC_0128.JPG

[Scott]

The photos of the bilge battery box are on SSD's site under the projects list, but are located under the title "Water Spirit Battery", not "New  Battery Box".  Water Spirit's setup looks pretty good.

[SailingSeaDragon]

When adding battery boxes to Sea Dragon, I tabbed it the hull...

http://www.sailingseadragon.com/ThirdBattery.htm

Garner

[Scott]

Garner,
Was there any noticeable difference in sailing/listing as a result of the addition of the batteries to the port locker?  I'd like to keep my bank together in that area if possible.  Did you ultimately put the starting battery in the starboard locker to offset the weight?

[BlameItOnBuffett]

I have 4 6-volt Trojans in the port locker, and have no list. Might be because they match the big A/C compressor/condensor in the starboard locker.

[slokat]

If you store stuff in the pilot birth it probably weighs more than the batteries, plus it is above the center of gravity... 

heck ten extra gallons in the starboard water tank probably balances out the batteries.

I know the galley outweighs the chart table/electronics, but I don't lose sleep over it...

Could be an excuse for placing a crew member in a specific spot?   Sit here, don't move - you are balancing out my batteries...

[Atavist]

another place I'm thinking of adding additional batteries is in both lazarettes all the way to the stern... my primary bank is also in the port lazarrette so it would be a bit of a run to get the ones at the starboard stern connected but would be fine I think....

The only reason I am considering this is because I just replaced most of my rhode with 300ft of 3/8 chain which is uhmm... yeah like 500'ish lbs at the bow... so I figure 4 - 6 more batteries in the stern may help balance that a bit...

although I have to say .. from what I can tell the chain up front had no affect on her performance so it's not something I'm too concerned about.

[slokat]

Why'd you go all chain?

[Snboard976]

I just got back from the boat.  I took a piece of twine and routed it to the selector switch from the batteries just foward of bilge.  It is a 14 foot run to the selector switch.  Is that too long?

The battery bank is 300Ah.

[boykin]

I have 4 6-volt Trojans in the port locker, as well as a 12 volt starting battery. I have no list except when my std. water tank is empty and the port one is full. I would do it again! Boykin

[Snboard976]

I took the advice I got here and put the batteries in the bilge over the keel.  The installation was very simple.  I used 2 2x4s a few squirts of the West System Epoxy and some fiberglass cloth.  One of the 2x4s I cut down to make 4 U shaped brackets that I screwed together then tabbed to the hull.  The other 2x4 I cut in half to make two railings that would slide into the U brackets.  The railings can be taken out so that the batteries can be moved.  In the future I am going to put bolts with wing nuts to secure the railings.  I will also paint the wood and cover the batteries with plexiglass bolted to the railings with wing nuts.  Here are some pics of what I have so far.  Thanks to everyone for the advice.

Chad
Hull #32