Procedure for Operating a Refrigerator on a BOat

[Sharphooks]

So I’m about to begin a boat camping expedition. I have a refrigerator on my boat. I know the drill with an RV refrigerator that operates on both DC 12V and propane but I have zero experience with a refrigerator that can operate both on DC12V and via AC through an inverter.

I noticed there is a panel switch for the refrigerator BOTH on the 12V switch panel and a switch on the AC panel (with the inverter switch)

Is the proper procedure to turn OFF the DC 12V switch when underway with the outboards and switch both the refrigerator switch and the inverter switch “ON”, then once at anchor and the outboards are shut down, turn the inverter switch and AC battery switch “OFF” and operate only on DC 12VC until firing up the outboards the next morning?

Thanks for comments, Gents

 

[Rain City]

So I’m about to begin a boat camping expedition. I have a refrigerator on my boat. I know the drill with an RV refrigerator that operates on both DC 12V and propane but I have zero experience with a refrigerator that can operate both on DC12V and via AC through an inverter.

I noticed there is a panel switch for the refrigerator BOTH on the 12V switch panel and a switch on the AC panel (with the inverter switch)

Is the proper procedure to turn OFF the DC 12V switch when underway with the outboards and switch both the refrigerator switch and the inverter switch “ON”, then once at anchor and the outboards are shut down, turn the inverter switch and AC battery switch “OFF” and operate only on DC 12VC until firing up the outboards the next morning?

Thanks for comments, Gents

Just keep it on DC at all times. The AC function should only be used when on shore power and your AC panel is juiced up. In fact, you may even want to turn your fridge AC breaker off if you plan on using your inverter for other things. And in that case just turn the inverter on when you need to use them and then back off. This is all assuming that your AC and DC systems are running off your house batteries.

 

[BC Coast Pilot]

I just leave mine on the inverter and don't bother with the 12 v.
I leave both power sources on and let the fridge figure it out. The 120v seems to create less heat in the wiring as the amps are lower when running on the ac.
That being said I have the inverter on a house bank which is separate from the motors so drawing down is not a concern. In my boat the DC draws from the 12v panel which is factory powered from the stbd engine bank which could be a concern.
So I guess the questions are:
Where does your inverter draw from?
Where does your 12v panel draw from?
It might actually be the opposite of what you suggest?

 

[Sir Reel]

So I’m about to begin a boat camping expedition. I have a refrigerator on my boat. I know the drill with an RV refrigerator that operates on both DC 12V and propane but I have zero experience with a refrigerator that can operate both on DC12V and via AC through an inverter.

I noticed there is a panel switch for the refrigerator BOTH on the 12V switch panel and a switch on the AC panel (with the inverter switch)

Is the proper procedure to turn OFF the DC 12V switch when underway with the outboards and switch both the refrigerator switch and the inverter switch “ON”, then once at anchor and the outboards are shut down, turn the inverter switch and AC battery switch “OFF” and operate only on DC 12VC until firing up the outboards the next morning?

Thanks for comments, Gents

Juts leave the 12volt always on. Turn on the AC panel when connected to short power. This is what I do. Then if you have a power failure or forget to turn on the 12volts its always on. When not using the boat I turn both off and clean and dry my fridge and leave the door open so it does not get mold.

This is from my Nova Kool fridge manual:

When fitted with the optional AC/DC module, both AC & DC power can be connected to the module at the same time. The unit will always run on AC when AC is available. Should the AC be disconnected there is a 1-minute time delay before the unit continues running on DC. If AC power is reestablished there is no delay, and the unit will immediately resume running on AC

 

[Sharphooks]

So is it a corretc assumption that if I were building a boat that would never come to a dock, never plug into shore-power, there would be absolutely no reason to install an inverter? In the case of my refrigerator, it would just run on DC power and an inverter would be useless without shore-power?

 

[Rain City]

So is it a corretc assumption that if I were building a boat that would never come to a dock, never plug into shore-power, there would be absolutely no reason to install an inverter? In the case of my refrigerator, it would just run on DC power and an inverter would be useless without shore-power?

For the purposes of your fridge, yes.

 

[Sir Reel]

So is it a corretc assumption that if I were building a boat that would never come to a dock, never plug into shore-power, there would be absolutely no reason to install an inverter? In the case of my refrigerator, it would just run on DC power and an inverter would be useless without shore-power?

An inverter has nothing to do with shore power and is what creates 120 volt AC from your 12 volt battery when turned on by you. That way you can run 120 volt AC appliances or electronic devices without shore power from selected AC outlets on your boat. It is not very efficient and drains batteries quickly - but good to run say a microwave for a few minutes or charge a laptop, camera battery etc.
You can still have shore power without inverter. The shore power would run into your charging system and keep your batteries topped up.
You could aslo have a few AC outlets.

It sounds like your Sea Sport is set up very similar to my Commander. Just leave your inverter off, Fridge on 12v, and you will be fine.
If you did not turn on the AC switch for fridge, but were plugged in to shore power, the charging system would keep your batteries charged.
WIthout the engines running and shore power not connected I suspect your fridge might last 3 days before draining your batteries.
That is why I installed a 340 watt solar system. I can pretty much last indefinitily on the hook

 

[CBsqrd]

Run the fridge on AC when plugged in to shore power (more efficient), otherwise leave it on DC - including when the engines are running. When running, your engine alternators are sending charge to you batteries which are powering your fridge directly.

You could run the inverter to power the fridge when running, but in that case the alternators are sending current to your batteries, which is then passing through the inverter to convert 12V DC to 120V AC, and then powering your fridge. But you are losing 10% - 15% (with a good inverter) of the energy to heat loss in that step. That thermal loss isn't a issue if you need to run something off 120V when you are on the hook, but personally I would prefer to use the energy as efficiently as possible.

 

[Gong Show]

In my experience, straight 12v dc fridges have the least amount of problems.
Three way, AC/DC/Propane have the most problems.

I turn the thermostat down a bit at night, when not opening the door, and then up a bit when I first open it in the morning.
Seems to keep the compressor cycling down a bit during sleep time.

The thermostats seem to be consumables and need replacing more often than I would have thought, every 4 to 5 years.
If the compressor is cycling on and off at irregular periods, likely a bad thermostat.

 

[NOOMA]

Maybe a little off the OP's question. Having had fridges in boats for over 32 years and various RVs for 40 years without ever having a repair, I think the secret is to not put warm food or drinks in a warm fridge causing the compressor to work overtime. With RVs , the fridge was on 24 to 48 hrs before loading and with the boats, the fridge is never turn off except for a few hours once a year for defrosting and cleaning and when on the hard for maintenance that is more than a few days.
Hope this helps someone. Ted

 

[RiverBoy]

An inverter has nothing to do with shore power and is what creates 120 volt AC from your 12 volt battery when turned on by you. That way you can run 120 volt AC appliances or electronic devices without shore power from selected AC outlets on your boat. It is not very efficient and drains batteries quickly - but good to run say a microwave for a few minutes or charge a laptop, camera battery etc.
You can still have shore power without inverter. The shore power would run into your charging system and keep your batteries topped up.
You could aslo have a few AC outlets.

It sounds like your Sea Sport is set up very similar to my Commander. Just leave your inverter off, Fridge on 12v, and you will be fine.
If you did not turn on the AC switch for fridge, but were plugged in to shore power, the charging system would keep your batteries charged.
WIthout the engines running and shore power not connected I suspect your fridge might last 3 days before draining your batteries.
That is why I installed a 340 watt solar system. I can pretty much last indefinitily on the hook

my neighbours kingfisher fridge draws crazy amps. so much so, the kicker can barely keep up with the fridge and other electronics running. he also installed a solar system to help out. his batteries are all tip top and wired professionally. to the OP i would keep an eye out on the draw if this is your first time just so you don’t have a dead battery issue . can’t wait to see your trip photos. always a highlight

 

[wildmanyeah]

How well do the solar panels hold up on boats with ponding waves? anyone had any issues?

 

[Sir Reel]

My canvas, with the panels mounted on it, will flap around a fair but in wind and waves but so far no issue in 2 years of use.
I have Sunpower panels and here is what they say:

SunPower’s flexible panels are constructed with top-grade, lightweight polymer materials, allowing for easy transport, installation and panel flexing up to 30 degrees.

 

[BC Coast Pilot]

So far so good. I get 10 to 15 amps on an overcast day.
200 watt panels Solid mounted.
Runs the inverter and fridge and stereo
24/7

 

[sasqman]

So far so good. I get 10 to 15 amps on an overcast day.
200 watt panels Solid mounted.
Runs the inverter and fridge and stereo
24/7

Nice set up! What does the control Guage look like for your solar setup? What kind of information does it tell you?

 

[Sir Reel]

I have a Victron battery monitor and solar charge controller. Both Bluetooth to an app on my phone.
this is what I see.

 

[BC Coast Pilot]

Nice set up! What does the control Guage look like for your solar setup? What kind of information does it tell you?

It does 2 battery banks and has BT. It tells you voltage, amps and amp hours for each bank on the display a usb charger and a pile of stuff on the app. I like to be able to look at the numbers and know all is well at a glance without digging through an app.
Gopower 30amp. Carmanah technolgies.

 

[Thunder21]

My 12v fridge only gets turned on for longer trips. I’m trolling or running for 12 hours a day in that case so my fridge stays on the entire time. I’ve got 2 6v rolls house batteries in series and troll on a 200hp engine and it’s never been an issue .

 

[sasqman]

It does 2 battery banks and has BT. It tells you voltage, amps and amp hours for each bank on the display a usb charger and a pile of stuff on the app. I like to be able to look at the numbers and know all is well at a glance without digging through an app.
Gopower 30amp. Carmanah technolgies.

Thanks!
Great info.