Trojan Boat Forum

Hi all,

I got a lot going on my F25. Right now working on my front cabin windows. Also got anchor items on my mind, but also working on something that's been on the back burner for months, and just now tinkering with it.

Keeping the 110v going while away from the slip. Some time ago, I bought a Cobra 1500 watt invertor to connect to my house battery so I could keep my small fridge going when away from the slip.

Yesterday I brought the battery home, charged it up after checking water level and hooked the invertor to it. I got a small fan about 5", and plugged it into the invertor and left it running, just to see how long it would run.

Six and one half hours later, it was still running strong. I had to unplug it to go to bed.

Not sure how much amps the fan was pulling, but it was a cheap fan, so figure at least 1 amp or more. My fridge pulls 1.3 amps as stated on the back label.

The fridge doesn't run all the time, so I believe I could at least get 6 to 10 hours with this setup?

I'm going to find something I think will pull a few more amps today and try it again.
Let you know how it turns out.

Larry

Larry,
I've been kicking this idea around for a while now that may be a potential solution to your problem.

Between the shore power plug and the panel, install one of these.

http://bluesea.com/products/9009

Hard wire in an inverter to the switch for the generator side and you should be set. One consern would be to isolate what you want to keep on by turning off breakers at the panel. Like, your battery charger. There's no point in having the batterys powering the inverter to power the battery charger to charge the batteries. ( I think that would disrupt the time space continuum. Chicken and the egg thing...)

Another concern is you have to remember to turn things back on or off when you get back to the slip. No need in leaving the inverter on while away. Also, breakers need to be turned back on when you plug back in. But it's managable.

Just an idea.

Also, you want to isolate your starting battery and house battery banks. Maybe instead of a battery switch, install a battery isolator so it's automatic. Don't want to loose juice on your starting battery.

Larry... you need to ensure that you are not draining the battery by more than 50%. If you do that often you will kill it.
So look up the specs for your battery (I hope it is a deep cycle) and find the Volt level for 50% charge... now you need a Volt meter connection to it that you can turn on to check the Volts after some hours... that will tell you how much of a drain you have on your battery.

Side note: you are making sure that the gauge of the wire from battery to Inverter is correct gauge for the distance run and the max: load of the Inverter. Likely #2 AWG cable is best

Ken, Michael,

Great advise, looked up the switch, a little costly, but looks like it's worth it. All wiring is to spec's for the Cobra inverter. It also has a digital volt readout with a low battery cut off. And the battery is a deep cycle, rated at 75 AH. (24)
Michael, I will take your advise and install an analog volt meter to keep an eye on the battery.

I do intent to isolate the start battery from the house. I have a switch that came with the boat that can do this, but I don't like the idea of having them wired together and forgetting to flip back and forth. I know some will disagree with that. But, the battery switch will go. The start and house batteries will have their own chargers while on shore power, and in the near future I intent to install a solar charger for the house battery to help keep it up while off shore power. This will all take time as my funds are limited. But now I at least have a battle plan.

Thanks very much for your suggestions, a great help.

Larry

larry i run my f32 on an invertor a whole lot not for my main ac/dc norcold fridge but the other things i like to use but i do run another ac fridge sometimes in addition to the norcold. i have sized my house bank accordingly.i use golf cart batteries. i have set it up where i only have to run my genny if i want ac or stove. i dont gather you are trying to go all out with only using a 1500 watt invertor but i will give some advice that i have.
1) your fridge may have a plate that shows 1.5 amps but i bet if you look closely this is ac not dc. this is important because as the inverter is using 12vdc to run it you will be using much more amps dc from the battery than the 1.5 amps you think.
2) a group 24 battery with only 75ah will not last very long. to keep from prematurely ruining the battery it is understood to use only 1/2 of the rated amp hours capacity. i believe you will use more battery than you might think
3) depending on your inverter and the wiring on the house/boat you cannot simply wire up the output of the invertor to the generator/shore switch. an invertor is hot on both legs and many times the ground is connected to the neutral side in the ac panel. if you short the neutral leg to ground the invertor will be toast. you can make a work around and power outlets but its a little more to it. i can explain if you want to know. i power the stbd side of my boat by simply flipping a switch.
4)the only way to be certain of what your invertor is pulling out of the battery is using an dc amp meter while running what you want and you will then know how to size up your battery properly.

Sounds like a lot of work and expense to keep a 'small fridge' going. The 'small fridge' I used to have on a 28' boat would hold 2 diet cokes and 1 banana. I bought a 120 quart heavily insulated cooler and it would keep our refrigerated items for a week no problem. I eventually took the fridge off the boat and converted the space to cabinets. Those 'small fridges' are a nice novelty on a boat, but in my opinion, totally useless.

Larry,

If you're looking at Blue Seas take a look at their ACR set up (Auto Charging Relay). It isolates and senses the house and engine banks and depending on how you hook it up it will sense the demand on the house bank as well as the engine, making sure that the one does not drain the other. I installed one of these a few years ago. I also installed the auto relay switch on the dash. This allows me to either turn off the ACR or combine the batteries (never have). I now just leave my single 1-2-All-off switch on "2" (house bank). The engine battery is isolated only for the engine. I installed 2 group 29 (125AH each) batteries in the "dead" space behind the drawers on the port side of the cabin. This is plenty of power, and would most likely also be plenty for your inverter. The beauty of the ACR is that if your inverter drains your house battery you will never lose engine starting power. The ACR is under $100 I think. They have a full description of it as well as different wiring diagrams, and their tech folks are very helpful.

Fortunately I know a lot about wiring.....a LOT more than I do about plumbing water heaters (from my last post).

Hope this helps.

vabeach1234

Got any pic's of your boat, inside and out? Would like to see.

Thanks,

Larry

Larry,

Here are links to the albums I have set up on photobucket. They are pretty disorganized but they are all of my boat. Unfortunately most of the pictures are of stuff I was working on and not of me having fun using the boat.

http://s853.photobucket.com/albums/ab96 ... jan%20F26/

Old poor man's air conditioner...
http://s853.photobucket.com/albums/ab96 ... nditioner/

New Marine Air Conditioner...
http://s853.photobucket.com/albums/ab96 ... 20Install/

http://s853.photobucket.com/albums/ab96 ... aul%20Out/

http://s853.photobucket.com/albums/ab96 ... %20Galley/

Ken,

Your boat looks great, I hope to have ours looking that good some day. I have a list of "to do" things as long as my arm, and slow but sure, I'm getting through it.

I noticed the rod holders you have on the hardtop. I have looked all over for some like that, could I ask where you found them.

Thanks very much,

Larry

Larry,
If you could see her in person, you'll see how her age shows. She's in desperate need of a paint job on the top sides. Believe me, my list of things to do is just as long. By thanks for the compliments. The rod holders mounted to the hardtop I got at Cabelas online. Here's a link to them.

http://www.cabelas.com/cabelas/en/templ ... hasJS=true

They are aluminum but seem to be holding up in the saltwater environment. I've had them on for I guess going on 3 to 4 years and don't see any corrosion. I usually use them for rod storage when trolling but will use a spinning rod for trolling in one with light drag. If a big fish got on, I trust the rod holder but would be concerned about the hardtop strength.

Thanks again.

Ken