Inverter / Battery / charger

[PeterPalmieri]

I do not have shore power down at the dock.

Every time I want to bring my shop vac down to the boat I have to drag my portable generator my AC plugs are useless on the boat except when we go over to the beach in the summer.

I would like to run a coffee maker or use the shop vac for short periods on DC power. Not all that interested in fridge, AC etc. trying to KISS

I'd also like to run DC stuff like boat lights etc off shore power either in the winter if I'm doing a project and have my generator to plug into the shore power or if I'm at a location with shore power and not run down the batteries.

So I'd like to be able to flip a switch and go eitherway (no LGBT jokes please)

Also being that the boat stays in the water during the winter I'd like to be able to bring down the generator and charge the batteries periodically.

On occasion I'd like to bring my generator out for a long fishing trip or overnight on the hook.

Right now I have a battery for each motor and mostly original wiring and single pole breaker. How involved is this to accomplish?

[Bruce]

For a simple plain portable charger/inverter I've had good luck with AIM units. I have a 2500 watt unit.

http://www.theinverterstore.com/1500-wa ... arger.html" onclick="window.open(this.href);return false;

They are rated in watts which is the ac voltage x current(amps). Example if you have a coffee pot that runs off of 120v ac and draws 10 amps, it uses 1200 watts of power. You would need a 1500 watt inverter. Most portable inverters have cables with clips to clip to the battery connections or you can use lug ends for a more secure connection and comes with ac outlets to plug stuff into.

Now the other side of an inverter. To figure battery draw when using an inverter you take that same 1200 watts and divide by 12v dc to get the current draw to the inverter. Surprise it is 100 amps. Your pulling 100 amps out of your battery and on a single battery it wouldn't take long to kill it.

If it is an engine start battery and not a deep cycle, you'll shorten its life too. To figure time usage you'll need to know your batteries amp/hr capacity.

The best unit is a Xantrex, but they are expensive and its a permanent hard wired in unit.

[Keith Poe]

I have three batteries and an inverter microwave just start the motors and all is good so far

[Kevind767]

Bruce,

I have a 2500 Watt AC Delco unit with 2 GFI plugs for the outputs.

I would like to hard wire the inverter to supply a buss to power more than just 2 items.
How can I do this , and still keep the GFI protection for the circuit?

None of the other items will be more than the 2500 watt output, even running at the same time.

[Bruce]

Without going internally to the inverter wiring, you would have to use a 3 wire cable and male plug end into the outlets and then the other wire end into your junction box to power more objects than just 2. Basically an extension cord, but a much better quality plug and wire. 2500 watt could produce loads of up to 20 amps continuous or even higher intermittent. The outlets on the inverter should have a side notch indicating the outlets can handle 20 amps. You'll need to make sure your plug is rated 20 amps also. In my junction box I would have a 20 amp breaker protecting the plug and wire from the inverter before I fed anything else and then the appropriate breakers to feed individual devices or outlest.

And like high current plug in devices, that pressure connection between the plug prongs and outlet don't exactly produce great contacts. Its something you would need to keep a good eye on for looseness and corrosion.

You'll keep the GFCI this way as the GFCI is looking for any leakage current with in the circuit. But caution. While GFCI's are good around wet locations, many appliances don't work with them. There is enough leakage current internal to some appliances to cause the GFCI's to trip. You may find you have issues tripping the GFCI on some things.

Garages have been coded to use GFCI's in them. There's been more than one horror story of a garage frig or freezer tripping that GFCI and next time some one goes to grab some sausage and opens the door, they hurl from the smell and 1200 bucks worth of half a cow is trash.

My son in law didn't listen to my sage advice and learned the hard way on that one.

[Kevind767]

Kind of what I was anticipating.

Going internally and removing (Bypass) the GCI outlets, other than properly rated fuses and correctly sizing the wiring, Am I forgetting anything else?

As you point out, the 3 blade plug doesn't sound like a proper connection for vibration and boat applications.
Doesn't instill confidence as an electrical setup. And I can foresee those corrosion problems ahead.

Thanks for the advise

[Bruce]

Given what I've seen in what is now 45 years of working on boats since I was ten, you'd be surprised what I've seen that supposedly passed as proper electrical even out of the factory.

Wouldn't use fuses on an AC circuit. Use a breaker rated for AC.