Installing new battery bank...

[sunnydude2]

I have purchased two of my planned 4 6v batteries and the cables to wire them in as my new house bank. The boxes i bought are secured with 4 bolts. Not wanting to drill holes in the boat and wanting an easy way to remove the batteries when they die, i was thinking of epoxying in some plywood with the connectors for bolts that you mount from underneath and then screw down into.

My questions:

1. Will marine epoxy be strong enough?
2. Is there a better way to secure them?

Any and all comments appreciated.

I purchased 1/0 wire to run to the switch and 4/0 to connect the 6v batteries.

Also, would a 500watt generator run a battery charger in a pinch if needed?

Sean

Glassing in stringer blocks sounds like a good way to go. that'll give ya lots of material to bite screws into for securing everything. You could even go so far as to tint the resin up white so it's not so obvious what you did to accomplish it.

- Marine epxoy is more than strong enough. Just make sure you glass it properly. It's the glass that gives it the strength... not the epoxy.

- I would have used the same wire to connect all the batteries. The 1/0 wire is wasted with only 4/0 wire between the batts. Current is constant in series so those wires between each battery (and each battery) will carry the same load as the feed wire to your buss. I'd step up to 1/0 between them as well, or down to smaller on the feed. One or the other is wasted.

- 500W will work... In a 100% efficient circuit (not real world) a 500W 120V generator can produce 4.166 Amps (I=P/V ). Drop that to 12VDC and you can make 41.66 Amps. Piece of cake. :) Whats the amp requirement of your new charger?

[sunnydude2]

SS...what do you mean glassing?

I will check the amp requirements of the charger.

Thanks.

Sean

SS...what do you mean glassing?


Fiberglassing. Most people think that the epoxy itself is where the strength of fiberglass comes from, but that's not really the case. The resin (epoxy, vinyl, or polyester) just holds the glass fibers oriented and where you want them. Epoxy is a great adhesive and will bond the glass fibers well to whatever, but without proper glass structure, and orientation, you're essentially just gluing it in. The type of resin is important, but its biggest contribution to fiberglass (or any composite) is for flexibility. In carbon fiber and other types of graphite composites... 99% of the resin is removed in complex vacuum bagging and baking process.

If you wanted to glass in some wooden blocks, you could tint the epoxy white, and use some heavy roving to fair the blocks in and then some lighter cloth to finish things up and make them look smoother. It's actually pretty fun stuff to work with.

[sunnydude2]

I have never done any 'glassing', thought i could just get some marine plywood and epoxy = glue it down so i can mount the bolts to it. Might need to have you down to the boat for a consultation! :D Wife is getting tired of the battery box and cables taking up space in the back of her car!

Went with 1/0 as i could not find any labeling at all on my current cables. Since they are running another 6 -8 feet farther i went with the recommendation of going with 1/0 to not lose any current. The 4/0 is just for the jumpers on the 6v's and will be used to connect the other two and then to run up to the inverter. A little overkill maybe, but prefer it be done right. I might replace the existing cables that are on the boat as from the looks they appear to be 1 or 2 awg.

[TollyWally]

FYI,

Marine plywood is not needed. Marine Ply is very good stuff, fairly pricey. What makes it good is the lack of voids in the inner plies. This is important when bending plywood in curves to make sexy shapes like boat hulls. Hidden voids can create hard spots or fractures, not letting the wood bend in a fair curve. It is overkill for flat panels underneath batteries. Normal exterior plywood has the same glue as marine ply but is not graded to perfection in the inner plies.

It is common in the boat building industry to substitute AC or AA exterior plywood for marine ply when making cabins, etc., that are basically flat. A semi secret quality material is mdo plywood. Available either 1 sided or 2, it is the stuff exterior signs are painted on. Covered with a smooth paper overlay it takes finish quite well and stands up to the weather mighty fine.

Perhaps more than you wanted to know about plywood, could save you a few bucks without compromising quality.

Thats what my little Carver is built from, The lapstrakes themselves are MDO around a mahogany / cedar rib structure. It's weird to see that paper finish after all these years. :)

[Dave C]

Home Depot at Aurora Village had MDO in 1/2" a couple of months back. They sell it for signs. A 4X8 sheet was about $30 if I remember right. Nice stuff to work with.

[sunnydude2]

Thanks for the lesson on the plywood. :D Unfortunately I had already purchased my half sheet of marine 3/4 plywood on Saturday. I threw some primer and white paint on it to help protect it even more. Made sure to squeeze plenty of 4200 into the holes in boat before bolting it down. So the batteries are in, but ran out of time (Admiral called and wanted me home) so the wiring change is not completed yet.

[Never Again II]

Only a novice electrical guy, but I can tell you this...I just installed a second battery charger in our boat and it's a two bank , 20 amp (@12V) charger. I actually got on to post a question related to my install. Specs say it draws 5 amps (600 watts@120VAC). If your charger is a 20amp, it would be sketchy trying to run it on 500 watts. If it's 15 amps or less, I would think it would be ok. Reminder: Novice opinion based on one battery charger's specs on current draw.

[beyond kelp]

Sunnydude, you have the same boat as I do. I have the same batteries as you describe. Four golf carts for the 2000 watt inverter as well as the two starting batteries. You might as well enlarge your trim tabs now, because with all those bats, full fuel, dinghy, dingy engine, full water, etc. you will really need it! These 28 contessas are already in need of more trim tab area. You may have already done it as many others have seen the need for it. You are welcome to look at my install if you wish, mine includes a zantrex three stage regulator and a 120 amp dual belt alternator that puts out 13.5 volts at a very low rpm. G&H in everett one block south of everett ave behind carquest are a great resource for the alt, the isolator(you will not find one big enough easily at the marine stores if your experience is like mine) and anything you'd ever want to do with a starter also. Great people. their # is 425 258 3469. Looking forward to meeting whether you take me up on this or not. Congrats on the new baby. Awesome!

[sunnydude2]

BK...thanks for reassuring me that my battery plans aren't overboard. :) I have the "Tim the toolman" syndrome, MORE POWER! Must be able to run the espresso machine on the hook!

I will definately take you up on the looksy. This stuff is new to me and already my boating father-in-law is saying i have more battery than he ever had.

You are at Dagmars?

[3788sam]

Steve's boat has all the upgrades Bayliner should have done originally- Wait to you see under the hatches and see the big black upgrade!- :D

[sunnydude2]

Big black upgrade = larger holding tank? :)

We are starting from blank slate. After removing the ancient vhf's and cb, there are no other upgrades that have been done to our boat besides the new 5.7 in '97-99. Have all that extra space and feel the need to fill it. :D

Admiral just called to let me know latest toy arrived...new cd/mp3 for boat. :) Of course it was bought for her.

[3788sam]

He upgraded to the Vortec engine!

[3788sam]

But Tunes are important! Did that upgrade over this last winter. We put wired remotes up to the fly bridge and outside. I have one more to find a good home.

Also our head unit has the WX band as well. Nice to hit the button and listen to the weather!

[sunnydude2]

Ours doesn't have the WX but has a wireless remote. Admiral wants another set of speakers installed in cockpit. Oh will the projects never cease! :D

[beyond kelp]

We are at Dagmars , but my brother has a slip on A dock right in front of anthonys and I swipe it when hes gone as he is now in desmoines slip for maintenance( he lives on three tree point in burien on the bluff so its closer for large projects). You can bet if its a weekend and its not blowing 35mph or theres been a death in the family I will be transiting the poe twice a weekend. We have had Beyond Kelp for two and a half years now and average 250+ hours a year on the hobbs meter. Except for the new drive and engine period of dissillusionment and boat loneliness. My folks had my brothers slip as liveboards for 15 years as the first people to get a slip when the marina had a dirt parking lot as the new facilities were being built. I had the good fortune to have boaters for parents and went to desolation sound at two weeks old with my three brothers and I in a18 ft boat! Thats hard core dyed in the wool boater action, huh! One time it didnt stop raining there for the entire duration of the trip and that we all survived it is amazing. I live to go north, the farther the better. 310 miles north last year. The contessa has served us well. We fear no tides, no anchorage ( with our binford power supply,) and no mosquitos (Bens 100 percent deet). I love to look at others boats for ideas. Everyone seems to love their contessas. Call me at 425 3590624 anytime and I will share what Ive learned with you . And yes the 315 hp vortec cooks. Say goodbye to the paint on the props.

[sunnydude2]

Desolation Sound is how my wife got me into boating. She spent her summers up there on parents Islander 36 growing up. My first boating trip with her family was to fly up to Refuge Cove and hop on the chartered 53' Navigator and spend a week tooling around up there. Been hooked ever since. Before our 28' we had 21' searay that we would load up with friends, launch in Anacortes and head out.

Is your boat out on A dock at POE now? We are on P.

I need to get my wiring done before next weekend when we are heading out. Gone this weekend so I am relegated to evenings working on boat. :(

[beyond kelp]

Sean, with that as your introduction, you werent just hooked, you were hooked, played, then gaffed! :D Yes it is there and I will be there this afternoon sometime. I will know when in an hour or so, call me and tell me your schedule.

[sunnydude2]

I won't make it up there tonight, planning on being up there having a friend program my charger tomorrow night after 8pm or so.