Boat Electricals

[fulsik]

Hey all,

Purchased a tinny in which the previous owner pulled a part the electricals to power the lights. (yes I dont understand why ) Cables are every where and seems easier to start again. Lights are fitted but no battery, was a fish finder in the past.

1. What kind of battery do I need to purchase?

2. Does any one have basic instructions or can explain this process of installation?

3. Open for suggestions including safety, last thing I want is a fire

cheers

[fishingrod]

What sort of Electrics do you want to wire up ? (just lights ... or radio, bilge pump, sounder etc as well)

Re the battery choice.

That depends a lot on:

-how many electrics you want to run

-how long you plan to be out at night

-does your motor charge your battery

-and do you start your motor with the battery

-area of operation (for very calm waters you can get away with a low cost generic car battery if its not critical to start the motor)

You should use double insulated wire with tin plated copper for marine applications. Its expensive, but will last the longest. We can suggest wire thicknesss etc after we know what you need to do. All connections need to be well sealed against moisture. You will get MANY suggestions from people here on the techniques and products to use. Lets work out what you want to wire up first ... then we can elaborate on diagrams, instructions etc.

Re Safety wise

A waterproof blade fuse holder located very near the battery is my first suggestion. Then smaller rated fuses for each individual electric item.

cheers

Rod

[Davemmm]

I found that an easy way to run the electrics around on my tinney.

As the gunnel is a rolled shape, 20mm conduit fits straight in.

On one side I have conduit from front to back with holes cut out in the appropriate spot to allow power wires to come out ie lighting cables and power. On the other gunnel I have the drive cable for my new electric protected by another length of conduit.

The conduit fits in nice and neat and covers the wiring beautifully.

Dave

[a boat]

Hi Mate and Welcome. Good advise from the others and what I would do is start again and run two heavy gauge tinned wires from battery to behind dash to a fuse block. Then what ever your fit, nav lights/radio/sounder just jump off the fuse block.

The battery would best to be a marine battery around the 500 CCA in a battery box and running the leads thru conduit is a neat way of doing the job.

If fuse and fitted correctly not much chance of a fire,

If you are not confident bring the boat up and i can give a qucik course on how to do it correctly.

Cheers,

Huey.

[fulsik]

Thanks for the replies.

The essentials only. Lights for late summer afternoons and fishfinder. The motor is cable start and does have an alternator to charge.

Boat will only be on calm water like Georges river and port hacking. If the weather clears today I will get some pictures.

[fishingrod]

Throw up some pics and we can try and give some hints on switch panels and locations etc.

It would probably be worth putting in a small but reasonable system (backbone so to speak) that can give you the opportunity to expand to 4 or 6 electrical devices later on.

If your going to the trouble of wiring it up, i strongly suggest a bilge pump as well. They are relitivally low cost and good piece of mind. Around 500-1000gph would be a start.

If your motor doesnt charge the battery then try not to get to carried away down the track and decide you want a live bait tank. You could run it off the battery, but there is a chance of flattening it.

cheers

Rod

Edited September 9, 2007 by fishingrod

[fulsik]

Find attached.

Hopefully this will give some ideas.

Edited September 9, 2007 by rzep

[traysexy]

..gday

Another great idea like the photo shows is using a 'jiffy' inclosue to mount a switch panal.. With that, also a plus is using cable glands, not gromets!. Glands will protect the box from anything going inside as you can tighten them around the cable, so you can hose the boat out wil no worries about water going behind the switches, also a plus for salt water prevention. A standard automotive gromet will suffice, although personally I perfer glands.

Pete:)

[fishingrod]

Sorry to the mods if the links here are out out of place. Its a bit hard to give links to websites here as it can clash with our sponsors. All this equipment would be available for order via Huett Marine. Plus they have already offered to give some advice to wire it all up.

Im not sure how sensitive your boat is to weight balance and trim. A small deep cycle battery would be ideal in your case (but they can be rather heavy). Or the 500CCA battery that Huey suggested would work a treat too. You could really get away with a medium sized car battery if your are only in the river and not giving it too much vibration (thats my humble opinion)

A battery Box

http://www.bla.com.au/index.php?fn=product...b5653bbd4be5d94

A waterproof fuse holder right near the battery in the positive lead. Load with a 20-30 amp fuse.

http://www.bla.com.au/index.php?fn=product...b5653bbd4be5d94

The plastic box idea is good to mount a switch panel. The box should have some kind of o-ring seal around the lid. Run a bead of silicon around the edge when screwing the panel front down. Its not a bad idea to drill 1-2 small holes at the bottom of the box to let any water that might get in to drain out. Also use cable glands where the cables go in and out to keep it sealed. http://www.cabac.com.au/ims_docs/GN9PG/GN9PG.htm

You want a water resistant switch panel. There is heaps of models and suppliers to choose from with 4 switches upwards. Its always good to be able to access the fuses from the front without pulling the whole thing apart. But its hard to find a water resistant panel with front fuse holders.

http://www.bla.com.au/index.php?fn=product...b5653bbd4be5d94

Use 40amp wire to run from the battery to the switch panel, then, use the 16 amp wire for running from the switches to each of the electrical devices. Most retail marine shops will sell the wire to you by the metre.

http://www.bla.com.au/index.php?fn=product...b5653bbd4be5d94

Bilge pump. 500-1000 gph

http://www.bla.com.au/index.php?fn=product...b5653bbd4be5d94

Whoever you buy the pump off can suggest hose and fittings.

There is many variations available for all these items, including better, worse, cheaper and more expensive ones. Im just using these as ideas and examples. Im not endorsing any of the brands or models here.

All connections need to be well sealed. You can use automotive style crimps and heatshrink with glue lined heatshrink. There is also various brush on "liquid" electical sealers that i have used with good sucess. I normally give a few coats over a few hours to give a good layer.

The switch panel will need one positive wire going to it from the battery. Thats the red of the 40amp cable. (If the panel has indicator lights it also needs a negitive wire run to it) The positive wire from your sounder and lights would each go to their own switch. The packets often have a simple diagram to help.

You need a common negitive point where all the negitive wires join up. Run the black 40amp cable to it. All the negitives from the electrical devices meet up here. You can get a "buss bar" or even just a stainless steel bolt in the side of the plastic box can be a good common point. Use some crimp rings under a nyloc nut and washer.

hmmm maybe im getting too enthusiastic here ... its only a tinny. But it would be a installation to be proud of

cheers

Rod

[fulsik]

Thanks for replies.

Getting there with ordering parts, tin plated wire (learn something every day) . The control box was dead with internals rusted and screws gone.

My next questions is - From experience what size Battery to power nav lighting eg 8 hours max, small spotlight and a bilge pump. I guess this is question is like "how long is a peice of string?"

Had my eye on a AGM 12V 18AH but unsure if this is over kill. Keep in mind the Evinrude can charge as previous owner had setup.

cheers

[ATrezise]

Put simply, you need to work out the total current for the lights etc, multiply that by the max number of hours you want to run them and then roughly double it to get the battery size you need. You should never aim to flatten a battery.

So If you have std nav lights with say 10 watt bulbs, they will draw roughly .8amp each. A spotlight with a 100 watt bulb will draw approx 8amps but hopefully wont be on for too long and a 1000gph bilge will draw around 5amp (according whitworths catalogue) but again wont be on for long, hopefully.

Nav lights for 4 hours = 9.6amp, spot light for say 1hour = 8amp and the bilge for 10 min = .9amp.

Therefore 18.5ah req'd. Go for a 36ah battery. If you go bigger still you will have a much bigger safety margin.

If you change the bulbs in the nav ights to LED festoon bulbs they will draw only milliamps and you can use the 18amp you have your eye on, however agm are very expensive and not really needed for calm water. If the engine can charge the battery whilst crusing between fishing spots, even better.

I have LED nav lights, a sounder/gps, interior lights (again LED), a 1000gph bilge pump, a VHF radio and my battery is used to start my motor and I have a 750CCA (cold cranking amps) or approx 55ah battery and Ive not had probs.

Edited September 25, 2007 by AndyT

[fishingrod]

You might want to double check that your motor has a rectifier and regular installed. I think some smaller motors could only have a AC voltage lighting coil installed (i could be wrong). Then you need rectifier to turn it to DC volts, and then a regulator to make sure it doesnt over or under charge or fry your battery. Im a electronics tech by trade ... but not 100% familiar with outboards. The previous owner might have already checked it.

The 18AH hour battery sounds a little small if you want to run a a anchor light and maybe a fluro/work during the night. There may only be a little power left to run the bilge pump if needed ... or the red and green lights. You could always start the motor and you should get a few amps of charge coming off that. Ideally you dont want to drain your battery past say 50-60% capacity depending on type of battery. AGM as a rule is a bit more resistant to extra discharging. How long is your piece of string ? 18AH doesnt always mean you can pull 1amp for 18hrs. Check what discharge rate has been allowed for.

You can always get LED anchor and nav lights to save some battery power. They use less current than conventional bulbs. You might find that you only use your spot light for less than 1hr per night.

Those deep cycle, AGM or sealed typed batteries are generally suited to your application as you dont have a heavy starting load. You only have a slow discharge with slowish recharge from the outboard (or home plug pack). There are SO MANY different battery technologies around at the moment im not sure what direction to steer you in without spending lots of money ! If it was my boat id look at a 40-50AH deep cycle for maybe <$150. There are a few specialised battery shops around Sydney that will have more choice than your normal dedicated marine outlet.

Have you been out with the old battery in the boat and did the weight effect the trim or balance? That might dictate how big you can go.

cheers

Rod

EDIT : PS just noticed that AndyT typed while i was typing. All good comments there

Edited September 25, 2007 by fishingrod