Info on powering cabin Accecories

[chris0061]

Hello, I plan on adding a TV, DVD, and air conditioner to the cabin of my 24 foot boat. What I'm thinking is a portable air conditioner from Lowe's, 9.5 amp, I don't know how many amps the TV and DVD would be but what kind of set up would I need to run this? I'd put the stereo on it to. Any info would be great. Thanks

 

[Silvertip]

Re: Info on powering cabin Accecories

You need a generator or one very large bank of batteries and a big inverter. For the latter you would also need a place to plug in at the dock to recharge the batteries. A generator is a better and less expensive solution but has drawbacks as well. You need to be careful of carbon monoxide settling in the cabin.

 

[chris0061]

Re: Info on powering cabin Accecories

would a 6 bank battery sys work?

 

[pvanv]

Re: Info on powering cabin Accecories

That's a significant amount of amps. If you're at the dock, a regular 30a shore power hookup would be fine. Otherwise, you're probably looking at a generator.

To run this setup on an inverter would require a LOT of battery. 9.5a at 120v is 95a at 12v. So the inverter would need to be more than 1kw. That 95a load would fully drain a group-27 deep-cycle battery in less than an hour.

To answer your question about 6 batteries, well, if they're say group-31, you could likely run for a few hours. Very few 12v battery chargers will keep up with a load that heavy, but could possibly recharge the batteries after the a/c is turned off. You're getting to the realm of 4D and 8D batteries that are used on huge cruisers.

Some cruising sailboats have a/c setups, but they typically run on generator or shore power, because of the above-mentioned battery loads.

 

[chris0061]

Re: Info on powering cabin Accecories

OK so to set up for shore power what do I need? While I have the interior out do I put in a couple outlets then run some kind of plug threw the hull??? Is there a kit out there for that kind of set up? Also if I went that way then I could get a generator and when we beach I can set the generator on the beach and run a power cord to run the stuff? Does that sound more reasonable??? Thanks,

 

[Silvertip]

Re: Info on powering cabin Accecories

With all due respect, you are entering very dangerous territory if you have to ask the questions you are asking. Start by pricing the cost of a 1KW - 1.5KW (continuous) inverter setup. Then do a search on "marine AC power systems" and read about these systems and how they work. Then you need to consider where to put all those BIG batteries and of course the added 450# (approx) of weight. In a nutshell, the inverter contains a transformer that serves a couple of purposes. One is to isolate the boat system from the shore power system. It then feeds a service panel with circuit breakers for the branch circuits on the boat. It also feeds the equivalent of a battery charger to charge the battery when the system is plugged into shore power. When under way, the engine would normally be used to charge the batteries but with a system that size, the alternator on your engine would likely be the equivalent of spitting into a bucket and using the contents to douse a forest fire. The battery bank feeds a power inverter that converts 12V DC to 115V AC to operate the appliances. The more stuff you plug in, the more battery power you need to operate those accessories. If you plan to be out over a weekend, you need a very large system -- and did I mention how expensive that system is?. You need to do some research to avoid killing yourself or someone else so be careful regardless which system you add. To be fair about this, lose the A/C and you are now in a much cheaper installation.

 

[NSBCraig]

Re: Info on powering cabin Accecories

They have plugs with covers that you mount on the side of your boat.

Check iboats.

Then you need a breaker or two.

Only use marine wire they have marine (tinned) romex that works just like at home.

Use dielectic grease on everything.

(check iboats marine store)

 

[arks]

Re: Info on powering cabin Accecories

>>> LISTEN TO Silvertip and NSBCraig! They're absolutely right.<<<

OK so to set up for shore power what do I need?

It's fairly complicated to properly add 120v to a boat. You'll need a distribution system. Look at this: http://www.iboats.com/Marine_Electr...7081537--**********.706712221--view_id.469691

While I have the interior out do I put in a couple outlets then run some kind of plug threw the hull??? Is there a kit out there for that kind of set up?

No pre-engineered kits are available- too many variables.

As for the shore power inlet, you'll need a grounded marine shore power cable, and a bulkhead receptacle- like this: http://www.iboats.com/30A_Inlet_Non...97081537--**********.706712221--view_id.70407
The cabin outlets can be regular-type duplex outlets, but should be GFI protected.

Also if I went that way then I could get a generator and when we beach I can set the generator on the beach and run a power cord to run the stuff? Does that sound more reasonable??? Thanks,

It is possible, but you- and anyone else on the beach- won't enjoy the noise. Honda makes the quietest (non-marine) gensets available, and even they are too loud IMO. Lot's of people strap 2000 watt Hondas to their swim platform. It works but isn't the safest or quietest way to go.

Inverters and extra batteries work just fine for smaller 120v loads but don't expect them to run air conditioning.

If you really need to have air conditioning away from the dock, a permanantly-installed marine generator is the only way to go. Even a small one will cost over $5000 installed. Yes it's expensive, but worth every penny on a hot day! A properly installed generator also adds to the resale value, too.

 

[chris0061]

Re: Info on powering cabin Accecories

OK, a lot of good advice here. I may do without the AC and go with a two bank battery sys for small appliances with the inverter. I do have all the interior out so I can run two cable back were I'll put the batteries and mount the converter in a suitable place under the sink and be able to run small appliances. So with saying that what I would run is the DVD, TV, and a coffee maker in the morning so does a onboard battery charger operate off the batteries or does it need plugged in and I'm thinking a 4000 watt inverter.

 

[arks]

Re: Info on powering cabin Accecories

.... So with saying that what I would run is the DVD, TV, and a coffee maker in the morning so does a onboard battery charger operate off the batteries or does it need plugged in and I'm thinking a 4000 watt inverter.

I don't really understand that setence.

Yes, a 4KW inverter will operate those 3 items, but the inverter will need adequate battery power to be able to convert it from DC to AC.
As far as an onboard battery charger, they only work when plugged into 120 volts. When on the water, your boats engine alternator will have the ability to charge the batteries if the proper switches or an isolator are added.

 

[chris0061]

Re: Info on powering cabin Accecories

I just didn't know how those on-board chargers worked. I can do the mechanical work to a boat but for some reason it's hard for me to understand electrical. So does this sound reasonable? 1 starting battery and two deep cycle batteries and the inverter and charger. I seen 2000 watt inverters on eBay not too expensive. Or knowing what I want to run in the cabin can you suggest the proper set up with a wiring diagram? No air conditioner.

 

[pvanv]

Re: Info on powering cabin Accecories

Chris,

Think of the inverter as just a conversion from 12vDC to 120vAC, Kind of (but not) the reverse of a battery charger. The 12v wires will be heavier than the 120v side, and preferably fairly close (short run) to the battery bank, because there will be 10x the amps (plus efficiency loss amps) feeding in at 12v.

The coffee pot will make a fair draw on the amps. Not as much as the a/c, but still significant. There are some new 12v coffee pots out that are reasonably efficient, so that may be an option for you, especially if you have a well-wired cigar-lighter outlet. The old ones were a bad joke -- took forever to get warm, and never got very hot, and used a ton of battery. As for TV, DVD, etc, there are good 12v units out as well, some well-marinized, so your need for 120v may be less than you originally thought. Still, having 120vAC on board is a great convenience.

When shopping for inverters, I recommend you seek a marine-rated unit, especially if you will be in salt. Also, the continuous watt rating will be lower than the peak rating, so shop carefully.

When wiring everything, be sure to follow ABYC standards -- appropriate wire gauge and color code, marine type wire, proper terminations with adhesive-lined shrink tubing, proper grounding, and please use GFI-protected AC receptacles in appropriate enclosures.

Also, if you will end up with both shore power and an inverter, be sure that it's setup correctly. You would likely want a transfer switch if you go that route, or you can keep the inverter-fed outlets completely isolated from any shore power outlets. Based on the discussion thus far, you may want to contact a competent marine electrician to help you out.

 

[chris0061]

Re: Info on powering cabin Accecories

I think you may be right.

 

[Silvertip]

Re: Info on powering cabin Accecories

Any heating appliance such as an electric coffee pot or heater takes a tremendous amount of power compared to say a laptop, radio, or a small TV. For coffee makers I would suggest you use a small alcohol or propane stove mounted on one of the boat rails. Otherwise all that electrical capability makes for expensive coffee. If there is even a remote possibility that you will utilize both shore power and an inverter/charger on your vessel I strongly suggest you let a marine electrician do the install. I can tell by your limited knowledge and your own admission, that you don't fully understand the safety ramifications when dealing with AC power.

Just so you know at least the "basic" difference between inverter systems -- here goes (and this is just really simplistic)

A basic inverter that you see in all the auto and department stores, takes 12 volt DC power from a battery and converts it to 120 volts AC to run AC powered appliances. This is a one way system in that it has no shore power connection and it cannot charge the batteries either under way or at the dock. A 4000, 2000, 1000 or even a 500 watt inverter is limited to delivering that amount of power. The caviat is that in order to deliver that amount of power, the battery bank must be sized accordingly. For example, a single 12 volt battery powering a 4000 watt inverter would be dead in a matter of minutes at that load. Get the picture? There is no free lunch. That battery is a bucket of electricity. 4000 watts is equivalent to having a big hole in the bucket and it will drain in a hurry.

A more sophisticated system performs the same function, but it also includes a battery charging capability that can charge the batteries when plugged into shore power. A transfer switch disconnects the inverter function so the AC circuits are powered by shore power rather than the battery system. This then can be considered a two-way system. Wiring this system is not a job for someone that is electrically challenged.

Underway, both systems have the capability of charging the battery(ies) by the engine alternator. However, that alternator also is not an unlimited source of energy so recharging a very large battery bank from the engine would mean the engine would need to run for hours and maybe then not be able to keep up depending on what you had running at the time.

 

[chris0061]

Re: Info on powering cabin Accecories

OK, we will forget the coffee maker also, I have a Colman and a grill for the boat so we'll just stick with the instant. So the final set will be just running a fan, TV and DVD. The inverters I looked at on eBay had the outlets on it. The biggest one was 2000 watts peak power around 1200 continuous. Do I need a inverter that big? These will be run at night mostly. Lets forget the shore power. I'll keep it basic on this boat. I already have a starting battery and a new deep cycle battery and the switch for 1,2, or both. I have this in my other boat hooked up. Will those two batteries and the inverter do? Thanks guys for all the impute and patience with me.