Installing battery and electrical system

[Northern Tim]

My boat currently has no power on board - I use the pull start on the engine and have handheld VHF and GPS. I'm thinking of installing a battery so I can use electronic ignition and add a fishfinder/depth sounder, and possibly lights etc.

What components would I need to install a power system? I'm trying to work out the potential cost. There is a charging loop on the engine.

Thanks guys,
Tim

PS Sorry JK if this should be in the electronics bit, but I think I'm talking RIB electrics rather than electronics

[Nos4r2]

Does it already have an electric start? If not, it'll cost a fortune to convert unless you can buy a trashed engine+controls with the bits on you need. Probably cheaper to sell what you have and buy an engine with it all on.

[Northern Tim]

The engine does have the facility for electric start, it's just that I've never used it because I don't have a battery.

[Nos4r2]

That makes it much easier. I assume you've got remotes with electric start etc already wired up?

Does it already have battery cables on the engine? If it does,just hook them up to the battery and you should be charging it.

You'll definitely need a battery,battery isolator, battery box, fusebox (for all your electronic goodies) and a shedload of wire. Assume you need twice as much wire as you think you'll need.

<edit> and a small tube of sikaflex 291 to seal screws with.

[Poly]

Originally Posted by Nos4r2

You'll definitely need a battery,battery isolator, battery box, fusebox (for all your electronic goodies) and a shedload of wire.

Tim, if you are looking for a bodge - then you could do what I did (if you are wanting to do this "properly" then probably don't - but if you want to save cash and time read on)...

I bought a jump start pack from halfords. It lives inside my console where it is protected from the elements. Attach the engine power wires (chunky red and black) to the jump start leads (chunky red and black). This will give you battery, isolator switch, fused switched accessory socket, cheap mains trickle charger, and possibly a light inside the console! All for about the cost of a battery box at your local chandler. Been using this for nearly 3 yrs including the boat being stored outside for 1 year and no issues with it - but I decided this bodge was acceptable as like you electrics are nice to have rather than need to have.

[Northern Tim]

Cheers for the replies. Thanks to Nos for the list of "what you need" - that's what I was after!

[jyasaki]

If you're only running a couple of electronic items, you can kludge together a box to house fuses and such. I used a waterproof Otter Box; held a few fuses, a few solder connections, and a couple of marinized 12V outlets (car lighter types.) Oh, and a switch for a horn.

You can run a tractor/garden battery; should be enough to start your 25, and run electronics while powered down and drifting for a few hours. I think the last time I replaced it in the old boat, it was $39 US. I ran it without an isolation switch, but having one would probably be wise. Starting will be the highest amount of current you will see, so size the switch accordingly.


jky

[Thumperbob]

Originally Posted by Polwart

I bought a jump start pack from halfords. It lives inside my console where it is protected from the elements. Attach the engine power wires (chunky red and black) to the jump start leads (chunky red and black). This will give you battery, isolator switch, fused switched accessory socket, cheap mains trickle charger, and possibly a light inside the console! All for about the cost of a battery box at your local chandler. Been using this for nearly 3 yrs including the boat being stored outside for 1 year and no issues with it - but I decided this bodge was acceptable as like you electrics are nice to have rather than need to have.

This may be the answer to my prayers
Pol' - would this set up be enough to run nav lights plus the equivalent of "headlights" for mooring/recovering at night. do you think?
My SR4 has a manual Mariner 30hp with no obvious electrical output and since I already have such a charger/powerpack, it'd possibly be the simple solution to installing decent lights. . .

Bob.

[Poly]

Originally Posted by Thumperbob

This may be the answer to my prayers
Pol' - would this set up be enough to run nav lights plus the equivalent of "headlights" for mooring/recovering at night. do you think?
My SR4 has a manual Mariner 30hp with no obvious electrical output and since I already have such a charger/powerpack, it'd possibly be the simple solution to installing decent lights. . .

Mine is "plumbed in" to recharge off the engine so I can't say for sure. But if we look at the numbers:

It has a 21 Ah battery (if I remember correctly). Realistically you can use about 1/2 that - so say 10 Ah of power.

I am guessing nav lights use 5/10W bulbs. So say 2x 5W for side lights and 1x10W for all round white. Thats 20W with them on. 20W at 12V = 1.7 Amps. So you would expect to get around 5 or 6 hours from a battery pack - but then have no power left for lighting the trailer/slipway.

To get the equivalent of full beam headlights you are looking at around 50W each! So running a pair of them off the battery (assuming no nav lights) would zap the battery in just over an hour.

If you only need the full power for "docking" one option would be to have two battery packs - one for the nav lights and one for the spot light. Alternatively a very big torch with its own rechargable battery might be worth considering.

Another option worth thinking about - go to tesco's extra [has to be a big tesco store] buy a (or even better two) 3 W Cree LED torch (aluminium body about the same size as a mini mag light). £10. I recon one gives me about the same amount of light as my 15W halogen mountain bike lights - so enought to see what you are doing. Runs on AA batteries. Lasts a few hours at least - take spare batteries (and another torch so you can see to change them!). Seem to be popular as a cheap DIY Mountain bike set up - with various cheap options for attaching to helmets or handlbars - so could lash up something on your console/A frame I am sure.

Personally though I would investigate fully if there is any lighting coil on the engine as that would be much better.

[9D280]

Tim,

If you are only looking to start a 25, then a diddly little battery wuill suffice. I had a tiny wee thing on the SR - remember once it;s started the Alternator will probably supply most of the juice. In that case as Jyaski says, a small cheap battery will do, as your engine will pull start anyway.

On a similar theme, if you go "proper" wirth your installation,try to get the battery switch as high as poss. I had an issue after getting swamped that the swich terminals corroded in a matter of hours, and so couldn't pass enough current to start the Suz 25. Once I pull started it, it the alternator powered the radio (even on transmit) quite happily (using the battery through the dead switch as a "smoothing capacator"). Granted I never got round to fitting Nav lights or other toys on that boat as I bought the current museum before I got round to it.

[Thumperbob]

Originally Posted by Polwart

I am guessing nav lights use 5/10W bulbs. So say 2x 5W for side lights and 1x10W for all round white. Thats 20W with them on. 20W at 12V = 1.7 Amps. So you would expect to get around 5 or 6 hours from a battery pack - but then have no power left for lighting the trailer/slipway.

Personally though I would investigate fully if there is any lighting coil on the engine as that would be much better.

Many thanks for the sound advice - was looking at nav lights & all-round white today as well as clamps to secure to my A (single) frame. Next step would be to wire them up and lead them to the powerpack under the console.

But as a longer term solution, will take your advice and have a detailed look at the engine for a lighting coil.

Cheers