Wiring stereo, light, cig lighter to battery

[boatvinnie]

Hi,

I have a aluminum pontoon boat with an old 20hp motor.

The motor is not able to charge a battery, however I was hoping to install a stereo and two cigarette lighter adapters to a single 40ah marine battery. The boat is tied up to my house so I will just recharge the battery at the end of the day (and maybe add a solar battery charger during the day as a bit of a gimmick).

The stereo I am planning to use is a homebuilt combination of a d-class amp (very low power consumption) powering two small bookshelf speakers. The amp currently runs off a 12v 1.2amp power supply. I was hoping to wire this up straight to the battery, with only a fuse between the amp and the positive terminal.

The two cigarette lighter adapters would be used for a combination running light (white/red/green - about 10w) and a general purpose (GPS/charging ipod etc). The lights would be used only rarely, but it is nice to have the ability. The gps/charger would also only be used occasionally.
I was also going to wire these up straight to the battery with fuse in between.

Questions:
-Does this sound like it would work? Is there an easier way?
Would it be easier to run all three off a single fuse and a single connection to the battery?
-What size fuses are recommended for each of the three? I realize a 1.2 amp stereo would suggest a 1.2amp fuse, but do you normally add a little to make sure it doesn't blow all the time?
-I am assuming I would need to ground this, would the easiest way be by simply running a wire to the aluminium pontoons/railings?

Any help most appreciated.
-Vincent

 

[SKEETR]

Re: Wiring stereo, light, cig lighter to battery

Unless you like shocking your passengers do not ground electrical equipment thru the hull. All grounds must run back to the same battery and connect to the negative terminal. This also decreases power loss and prevents any electrolosis in the metal framing of the boat.
Use a duplex wire as opposed to a single strand.
http://genuinedealz.com/
For those power needs it should work for a days outing no prob. I'd recommend running a 12awg lead to a bus bar w/ 14/16awg feeders to your components fused inline for each components needs 2amp fuse would be fine for the stereo.

 

[Silvertip]

Re: Wiring stereo, light, cig lighter to battery

Ground on a boat is the negative terminal of the battery. Depending on where you install the battery, you can wire directly to it. But if the battery is located aft (as it usually is on a pontoon) and the stuff you add is at the helm, why run excess wire. Run a red/black pair of #8 wire to a fuse panel at the console. Wire the devices to the fuse panel and fuse accordingly. Fuse value for each device should be about 10 - 15% above the anticipated current draw of the device but never more than the current carrying capacity of the smallest wire in the circuit. The fuse panel will have a ground bus on it for connection of the ground wires. To protect the #8 gauge run, install a circuit breaker on the positive battery post. It should be rated for the a bit more than the total anticipated load but again, not higher than the ampacity of the wire.

 

[flargin]

Re: Wiring stereo, light, cig lighter to battery

solar chargers, unfortunately are not that good for 'recharging on the water' at most 5 watts for the smaller ones, you are delivering .5 amps... 40% of the stereo.

you can do it, but in reality, it will do so little compared to just plugging it in at the end of the day...

 

[boatvinnie]

Re: Wiring stereo, light, cig lighter to battery

Thanks for the replies so far...

Ground is the negative...got it. Makes sense now.

The battery is not installed anywhere, it will be built in as part of the 'portable stereo system'...see this thread for the idea:
http://www.diyaudio.com/forums/showthread.php?threadid=104402

I was planning to run the lights/cigarette lighter out of the same box, so it is all self-contained, can be removed as one at end of day, and can be taken to beach/festivals etc.

The solar charger is a bit of a gimmick, I realize, but 40% of the power of the stereo still gives you a much longer life...even assuming the stereo is at max power.

Any more tips/info appreciated...
-Vincent

 

[flargin]

Re: Wiring stereo, light, cig lighter to battery

The solar charger is a bit of a gimmick, I realize, but 40% of the power of the stereo still gives you a much longer life...even assuming the stereo is at max power.
-Vincent

If you have it in a box like that the solar chargers have some ability to be permanently mounted.... that will make it worth the effort. When people think they will take out the panels, hang them on the side of the boat... they will do it once or twice, and never use it again. this way, it will work at all times, a much better idea.

 

[Daley]

Re: Wiring stereo, light, cig lighter to battery

In addition to the good advice already given, consider using a marine battery instead of a typical car battery. Reason being is that marine batteries are designed to be discharged and recharged, whereas car batteries lose quite a bit of life by doing this. The trade-off is that car batteries will have a higher CCA, or ability to discharge a lot more current at once (like you'd have with a starter, which you don't have). A marine battery will last you much longer in this application, because of the constant charging/discharging and you don't need the mega current-draw.

Oh yeah, and as for the solar panels? I see no reason not to. They still work when the stereo's NOT on, so I say go for it.

 

[Silvertip]

Re: Wiring stereo, light, cig lighter to battery

Daley -- you didn't read the entire thread or look at the links did you! This system will include a couple of gel 7AH gel batteries.

 

[Daley]

Re: Wiring stereo, light, cig lighter to battery

d'oh! You're right - yeah I "read" it, but I need to learn to put the laptop away at midnight. Good call.