Jump to content

12v fridge to buy or not ?


petejj1104

Featured Posts

Hi everyone. I bought a boat but am a bit of a newbie.  As I get closer to moving my boat to my home marina I noticed today that the fridge and freezer onboard are the 240v kind. I immediately thought that this would drain my power on the route home and saw a second hand 12 v fridge freezer on fb. Is this an essential purchase? I am thinking that the previous owners were mainly marina based owing to the amount of electrics.  Any advice appreciated. Pete 

Link to comment
Share on other sites

How long have you got? If the fridge is a condenser 12 volt then they are much better than if its absorbtion. If the boat is fitted with a very good quality inverter/combi then a mains fridge makes sense. Do you have an inverter? make? type? this question can only be answered with MUCH more information :cheers:

Link to comment
Share on other sites

It depends on how much power the inverter uses by being on and the efficiency of the inverter vs the power draw of the 12v fridge.

 

For example, if the 240v fridge used the equivalent of 40Ah per day on 240v. You need to factor in the inefficiency of the inverter (say 90%) - 40/0.9 is 44amps. Then, how much longer you need your inverter on. For example, if you had it on for 8 hours a day normally anyway, but now you need it for 24. Mine draws 30w (2.5a) when on. So 16x2.5 = 40Ah. This bit is complicated a bit by inverter "search" functions which can reduce this power consumption. 84Ah a day total without calculating this. You decide if the difference between this (generalised) calculation vs the reduction you may (or may not!) get from the 12 fridge, is worth it.

 

I would look up both fridges, find their power draw, do this calculation and see if it's worth the cost to you

Edited by DShK
Link to comment
Share on other sites

32 minutes ago, petejj1104 said:

Hi there I have an inverter but as yet all untested. I think I saw a YouTube vid where a couple had a 240 v fridge and it was draining all their power. But appreciate every set up is different. 

 

You need to take the batteries effective capacity into account, but this will almost certainly be less than any labels suggest. You also need to take how well charged than batteries AND how you will recharge them adequately EVERY DAY!

 

A 12V compressor fridge will drain discharged batteries almost as fast as an inverter will, a small battery bank will be discharged faster than a large bank. Your question is not simple to answer but if you are running true to form for all too many new boaters I think that you would be well advised to study the Battery Primer pinned ta the top of the maintenance section and then do a power audit so you can work out how you will recharge the batteries.

 

If you are in a marine with a shore line then none of this applies, but as soon as you go cruising it will.

 

PS best ignore any solar charging until spring, if you get any it is a bonus.

Link to comment
Share on other sites

It's not worth changing anything till you have had experience with it, yes it will be drawing a lot of electricity, but if you are moving the boat the alternator should re charge the  batteries 

It's not the end of the world if you can't run the fridge 18 hours per day at this time of year. Your basics are rolls, tinned soup, butter, baked beans and eggs, smoked bacon in a vacuum pack and Cravendale semi skimmed would normally last three days. I turn my fridge on for an hour every time I open the door, and when the engine is running,  it is not ideal, but it's workable.

Edited by LadyG
Link to comment
Share on other sites

1 minute ago, LadyG said:

It's not worth changing anything till you have had experience with it, yes it will be drawing a lot of electricity, but if you are moving the boat the alternator should re charge the batteries 

It's not the end of the world if you can't run the fridge 18 hours per day at this time of year. Your basics are rolls, tinned soup, butter, baked beans and eggs, smoked bacon in a vacuum pack,  Cravendale semi skimmed normally lasts three days

 

 

I wish you would not make such bland statements like the red bit. The time cruising is vital, with an electric fridge half an hour will not cut it and I doubt the OP would recharge adequately in three hours. The four hours a day and eight at weekends maxim would be a good staring point without a power audit and charging data.

Link to comment
Share on other sites

2 minutes ago, Tony Brooks said:

 

I wish you would not make such bland statements like the red bit. The time cruising is vital, with an electric fridge half an hour will not cut it and I doubt the OP would recharge adequately in three hours. The four hours a day and eight at weekends maxim would be a good staring point without a power audit and charging data.

I thought he was moving the boat to a marina.

Link to comment
Share on other sites

Basically there are two types of 12v fridges - to put it simply 

1) Absorbtion

2) Compressor

 

A compressor fridge costs about £500 - £700 and uses comparitively little 'electric' An absorbtion fridge runs continuously and uses loads of electric. The instruction manual for an absorbtion fridge states that it should not be used without the engine running as it will flatten the batteries - they are designed for caravan use whilst being towed, if the car is stopped the fridge MUST be turned off.

 

A 'cheap' Facebook 12v fridge has a high chance of being a absorbtion fridge.

 

See extract from owners manual.

 

A 230v (mains) fridge will use a similar amount of electric as a 12v compressor fridge does, but, you will be using an amount (varying between not very much to quite a lot depending on make of Inverter) to power the inverter that changes 12v into 230v.

 

Only you can know how you intend to use the boat and make the decision to have 12v or 230v, but, if you intend to be in a marina most of the time and have electri hook-up I'd suggest sticking with the 230v one.

 

You can pay for a lot of Diesel or mains electric hook-up for the £600 you'll save by not buying a 12v fridge.

 

Screenshot (1473).png

Edited by Alan de Enfield
Link to comment
Share on other sites

29 minutes ago, Tony Brooks said:

 

I wish you would not make such bland statements like the red bit. The time cruising is vital, with an electric fridge half an hour will not cut it and I doubt the OP would recharge adequately in three hours. The four hours a day and eight at weekends maxim would be a good staring point without a power audit and charging data.

I worked on 4 hours minimum with help from the Adverc unit as the charge tailed off

Link to comment
Share on other sites

On your way to the marina... irrespective of what fridge you use if you can be bothered to manage it you don't really need one 24/7 in the winter.  Run it in the day when you have solar or are crusing with a bunch of freezer blocks in it, then transfer said blocks to a coolbag, dump any perishable stuff into that and put it outside.  But you don't even need to do that... as others have said, just turn it off at night. In most circumstances it will be fine until morning.

Link to comment
Share on other sites

1 hour ago, mrsmelly said:

How long have you got? If the fridge is a condenser 12 volt then they are much better than if its absorbtion. If the boat is fitted with a very good quality inverter/combi then a mains fridge makes sense. Do you have an inverter? make? type? this question can only be answered with MUCH more information :cheers:

 

No it doesn't.

 

Not in my experience anyway.

 

But the OP is planning to moor it in a marina anyway so there will be a mains power supply, in which case it doesn't matter a toss either way. 

 

Edited by MtB
Link to comment
Share on other sites

Whether you have a 12V condenser fridge or a mains fridge running off an inverter, it will typically use about half of your total domestic electricity consumption. And all of that electricity used has to be replaced or you will wreck your batteries in short order.  How you replace that power is a much bigger issue than whether you have a 12V or mains fridge.

So stick with what you've got for now, and see how you cope. At this time of year you can manage without a fridge anyway.

Link to comment
Share on other sites

22 minutes ago, David Mack said:

Whether you have a 12V condenser fridge or a mains fridge running off an inverter, it will typically use about half of your total domestic electricity consumption. And all of that electricity used has to be replaced or you will wreck your batteries in short order.  How you replace that power is a much bigger issue than whether you have a 12V or mains fridge.

So stick with what you've got for now, and see how you cope. At this time of year you can manage without a fridge anyway.

 

The OP also has a 240Vac freezer. I'm not sure it's cold enough outside to manage without that too. 

 

 

Link to comment
Share on other sites

21 minutes ago, MtB said:

 

The OP also has a 240Vac freezer. I'm not sure it's cold enough outside to manage without that too. 

 

 

Agree with that, at the moment temp is about 8C, it needs to be 5C to keep milk fresh, I keep my fridge about 5C, which is not really very cold, no way would I try to keep freezer compartment working properly, and a fridge freezer is just pointless,  just buy fresh food from shops.

 

 

 

Link to comment
Share on other sites

1 hour ago, MtB said:

 

No it doesn't.

 

Not in my experience anyway.

 

But the OP is planning to moor it in a marina anyway so there will be a mains power supply, in which case it doesn't matter a toss either way. 

 

I lived the 12 volt caveman lifestyle for a few years. I then bought a boat with a mastervolt set up and saw the light. The half an amp standby it took was bugger all in the scheme of things. The on 24 hours a day inverter enabled all mains equipment, this gave VASTLY more choice over 12 volt stuff and every item was very very much cheaper. The electrolux travel power was used for heavy stuff. Your set up that put you off going mains was probably just not thought out well, what did you not like about it?

  • Greenie 3
Link to comment
Share on other sites

3 hours ago, petejj1104 said:

Hi everyone. I bought a boat but am a bit of a newbie.  As I get closer to moving my boat to my home marina I noticed today that the fridge and freezer onboard are the 240v kind. I immediately thought that this would drain my power on the route home and saw a second hand 12 v fridge freezer on fb. Is this an essential purchase? I am thinking that the previous owners were mainly marina based owing to the amount of electrics.  Any advice appreciated. Pete 

How far is it from the boats current location, to your planned mooring?  Hours traveling or days/weeks. ( check for "stoppages" on your route, or you could be trapped for sometime.)

What electrical arrangments does your new mooring have?

Be aware that freezers in particular are very electrically hungry, so if that could be turned off, it would help greatly.

 

Bod

Link to comment
Share on other sites

How much power does a 12v compressor fridge draw? 3.5A? My freezerless mains larder fridge draws 4A. My inverter draws 0.9A but it's on anyway during the day as I'm working from home, so it's only really nighttime when I'm drawing more power and as others have said if you're worried about that you can switch the fridge off at night. 

Link to comment
Share on other sites

1 hour ago, Goliath said:

12/240v

 

just another option, 
12v when on tour

and 240V straight to fridge when on hook up, simple 😃

 

Not so simple given that the cost of mains in marinas is set to rise steeply. I've just got rid of my 3 way fridge for that very reason after the mains in my marina went up by 4x. 

 

My Dometic 3-way fridge drew 11A on mains through the inverter which just wasn't acceptable once the cost of electricity went up. Also have you seen the price of these fridges recently? I sold my 10 year old RM5310 model for £200. They are over £1000 new now! That should be enough to put anyone off.

 

I've installed solar panels now and only switch over to mains to run the washing machine so powering the fridge isn't an issue.

31 minutes ago, mrsmelly said:

I lived the 12 volt caveman lifestyle for a few years. I then bought a boat with a mastervolt set up and saw the light. The half an amp standby it took was bugger all in the scheme of things. The on 24 hours a day inverter enabled all mains equipment, this gave VASTLY more choice over 12 volt stuff and every item was very very much cheaper. The electrolux travel power was used for heavy stuff. Your set up that put you off going mains was probably just not thought out well, what did you not like about it?

 

I think the difference may be that you actually live on your boat.

Link to comment
Share on other sites

6 hours ago, blackrose said:

 

Not so simple given that the cost of mains in marinas is set to rise steeply. I've just got rid of my 3 way fridge for that very reason after the mains in my marina went up by 4x. 

 

My Dometic 3-way fridge drew 11A on mains through the inverter which just wasn't acceptable once the cost of electricity went up. Also have you seen the price of these fridges recently? I sold my 10 year old RM5310 model for £200. They are over £1000 new now! That should be enough to put anyone off.

 

I've installed solar panels now and only switch over to mains to run the washing machine so powering the fridge isn't an issue.

 

I think the difference may be that you actually live on your boat.

I live on my boat and it is a bit different, but most electronic stuff is 12volt. My inverter is off most of the time 

 think the only thing I do very different is laundry. I have a washing machine but no drier, one would need to be in a marina  in winter I have the stove on 24/7, so wash and drying socks or a T shirt can be done day to day. A   launderette is better for bedding and jeans etc

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.