Can anyone recommend an invertor

[Wittenham]

thanks both and you are officially smarter than Siri who said the two units were not comparable.

[Jen-in-Wellies]

2 minutes ago, Alan de Enfield said:

OK makes more sense now you have edited your post.

I had not put 2&2 together and realised he was looking for comparisons - I just answered his question.

 

Well done for interpretation.

Usually takes me two or three edits to get a post roughly how I meant it to mean and correct some of the spellllling mishtakes.

[WotEver]

27 minutes ago, Wittenham said:

thanks both and you are officially smarter than Siri who said the two units were not comparable.

To convert Ah at 12V into Wh just multiply the Ah by 12. So 50Ah is 600Wh.

 

In this case multiply the daily rate by 365 to get a yearly figure: 219,000Wh or 219kWh

[Jen-in-Wellies]

47 minutes ago, WotEver said:

To convert Ah at 12V into Wh just multiply the Ah by 12. So 50Ah is 600Wh.

 

In this case multiply the daily rate by 365 to get a yearly figure: 219,000Wh or 219kWh

10/10 for the correct answer and showing your working. ✔️

Jen ?

[Dr Bob]

So are 240v fridges more economic then?

[Wittenham]

15 minutes ago, Dr Bob said:

So are 240v fridges more economic then?

oh, oh, let me try, teacher....

 

**if** you buy a low energy 240V **and** your inverter is efficient enough to not give away too much energy, then it could be more economic.  For my situation, the 240V will trump the 12V.

[WotEver]

1 minute ago, Wittenham said:

**if** you buy a low energy 240V **and** your inverter is efficient enough to not give away too much energy...

... or is switched on 24/7 anyway...

[Alan de Enfield]

5 minutes ago, WotEver said:

... or is switched on 24/7 anyway...

But the 'losses' have to be apportioned to something.

 

"My freezer is very economical because the losses are taken into account in the calculations for the fridge", and when asked how efficient the fridge is "it is very economical because the losses are taken into account in the calculations for the freezer"

[Jen-in-Wellies]

30 minutes ago, Dr Bob said:

So are 240v fridges more economic then?

Depends if you believe the kWhr/yr figures that the manufacturers state for their 240V fridges. These will be generated under ideal situations, like mpg figures for cars. Has anyone measured consumption figures for a modern high efficiency mains fridge under boat conditions? The way the fridge is installed has a huge effect on power consumption. The rear of the fridge needs to have a good flow of air across it to cool the refrigerant easily. Mounting a fridge under a worktop with no ventilation in, or out is an ideal way to get the compressor to be running all the time. I had a slot machined in the worktop on my boat above the rear of the fridge, plus ventilation slots in the floor underneath, so cool air would be drawn from the bilge, over the coils and out the top of the work surface.

 

Jen

[OldGoat]

15 minutes ago, Dr Bob said:

So are 240v fridges more economic then?

Rising to the bait -

It's pointless  / misleading using standard published (methinks fiddled or somewhat artificial figures to justify one's position.

Case study.

My aged  Batts fridge freezer (NOT a fridge with a conservator section - but a separate freezer compartment) has well exceeded it's life expectancy. it needs new door seals and the door racks are broken. Still works but it's tatty. What was  'efficient' 20 years ago doesn't compare with modern electro mechanical compressor design.

The case was from the LEC factory in sunny Bognor-on-sea because that's all the likes of Maurice Batts and those very nice folks at Shoreline could buy-in. Not the best, because they were built to a price that could compete with their market segment.

In my view and experience, there's nothing really available for someone who wants a scaled down domestic fridge / freezer suitable for a pseudo marine environment that runs on 12/24v. Thus I've bought a Liebherr unit that fits the space available and suggests that its power consumption is better than all of the competition in the same size. It also has a good case and well designed (= solid looking internals).

I've tested it at home with a battery / inverter test rig - and figures suggest that it meets / exceeds the power consumption of Maurice's machine - thus I'm potentially happy.

After a  boating season - Deo Vult  - I'll come back and report....

 

My point is that one  has / you have to be practical in adapting a device (whatever it is) from a domestic situation to fit the minority market of boating and its sub-set of inland waterways. The trade off is one of price / power consumption  / suitability and your willingness to accept whatever their shortcomings may be.

On this forum it's clear that folks want to take their land based facilities and translate them without ANY compromise to a self powered different environment. It can be done - but only with some element of re-designing the resources that you have. 

 

[WotEver]

31 minutes ago, Alan de Enfield said:

But the 'losses' have to be apportioned to something.

 

"My freezer is very economical because the losses are taken into account in the calculations for the fridge", and when asked how efficient the fridge is "it is very economical because the losses are taken into account in the calculations for the freezer"

The losses are apportioned to whatever caused you to have it switched on 24/7 in the first place

[roland elsdon]

Walked past new boater at napton on way to work rumble rumble of engine, walked past on way home rumble rumble, this continued to the weekend 5 days. At this point owner sidles up and says youve been here a week , no engine no generator how?  

Told him during day only ch pump on.

what about the fridge ? What fridge it hasnt gone over freezing all week. Everythings in an ammo box under the cloths.

oh he said i have to run the engine 6 hours a day for the mains fridge and freezer...

 

lateral thinking no longer exists

[Dr Bob]

Just had a look at the power usage on my boat from the Raspberry Pi data wrt to the fridge.

Graph below.

From 8pm last night, my 240V fridge compressor came on 3 times overnight. Average time on 55 mins +/- 2 or 3, so that is 55 mins on in every 4 hours. Current used is circa 3.8A. Fridge was opened half a dozen times between 8-10pm then not touched. Temp in fridge 4-5°C. Temp in boat 21°C where fridge is. So that is 22Ahrs per day if extrapolated for the full day.

Power to the fridge via an inverter which is on 24/7 -an ageing Victron 2KW combi.

[Alan de Enfield]

16 minutes ago, Dr Bob said:

Just had a look at the power usage on my boat from the Raspberry Pi data wrt to the fridge.

Graph below.

From 8pm last night, my 240V fridge compressor came on 3 times overnight. Average time on 55 mins +/- 2 or 3, so that is 55 mins on in every 4 hours. Current used is circa 3.8A. Fridge was opened half a dozen times between 8-10pm then not touched. Temp in fridge 4-5°C. Temp in boat 21°C where fridge is. So that is 22Ahrs per day if extrapolated for the full day.

Power to the fridge via an inverter which is on 24/7 -an ageing Victron 2KW combi.

Am I reading it correctly ?

 

At 20:00hrs the fridge was drawing 12 amps, and 10-11 amps for an hour ?

Edited March 5, 2019 by Alan de Enfield

[Dr Bob]

3 minutes ago, Alan de Enfield said:

Am I reading it correctly ?

 

At 20:00hrs the fridge was drawing 12 amps, and 10-11 amps for an hour ?

Between 20.08 and 21.03 the compressor was running. Before it came on the current drain on the batteries was 7.5A (ish) and once the compressor was running it was pulling 11.3A so the delta - that used by the compressor was 3.8A. This is typical of what I have seen now I can look at it with the Rasp Pi. The fridge then came on just before 1am for 53 mins with a similar 4A differential. Just before 3am, one of the TV boxes (sky or BT youview) went into sleep mode - I assume- and then just before 6am, the fridge came on again. Just before 7am, Mrs Bob woke me up and the current draw increase as the water pump and vacuum pump started up.

It is interesting to look at the Rasp Pi output to see what kit takes what in the way of amps and the effect on voltage. These voltages are with the lithiums in circuit.

[Alan de Enfield]

6 minutes ago, Dr Bob said:

It is interesting to look at the Rasp Pi output to see what kit takes what in the way of amps and the effect on voltage.

What is your daily consumption ?

 

I'd estimate 150Ah.

[Dr Bob]

5 hours ago, Alan de Enfield said:

What is your daily consumption ?

 

I'd estimate 150Ah.

To be honest, I've never really checked. I can now with the Pi and will when we get out next week once I have the Lithiums fully working.

Typically overnight the BMV monitor is showing circa 100-110Ahrs out during the winter months.  During the day, the solar is putting it in as we are taking it out.

The plot from last night was artificially high as I was trying to drain power out of the batteries as they dont like being at 100% so the sky box, the BT you view box and the Rasp Pi for the TV and associated hard disk were on. Normally only one of the boxes would be on to reduce power out and we would turn them all off when we go to bed. They were all left on last night. Also, they are only on in the evening so the daytime consumption is less.

The rasp Pi makes it very easy to monitor power useage.

Once I get the Lithiums sorted, I will look over a  24hr period at the fridge useage.

[mrsmelly]

Having lived full time with 12 volt fridges and full time with mains fridges I always go mains. Much cheaper to buy with better choice and in reality use a similar amount of leccy to run. The difference alone in equipment costs throughout the boat pays for a first class inverter with change. Its a no brainer for me. Done  it again on this boat having sold the matching 12volt fridge and freezer units and replaced with proper, superior mains units. 

[Markinaboat]

On 02/03/2019 at 18:55, WotEver said:

Yep, Phil is pretty good. I’ve had my disagreements with him though, he’s not perfect. 

Yes, several. Tony B for one. 

Graham Mills runs the 12v Group. Extremely knowledgeable and generous with his time.

[WotEver]

On 05/03/2019 at 18:24, Markinaboat said:

Graham Mills runs the 12v Group. Extremely knowledgeable and generous with his time.

No he doesn’t. Wrong group.

 

Graham Mills has some VERY odd ideas. He left this forum in disgrace, moved to TB and was seen through there quite quickly and left there too. He eventually ended up on the ‘12V Boating Group’ on Facebook which is owned and run by Phil Brooke-Little. In July last year Phil had finally had enough of him and blocked him from the group. GM then set up the similar-sounding ‘12V Boating Group Graham and Others’ which has less than a third of the members of the original. 

 

The last I heard about Mr Mills was that his latest crusade was to attempt to bully Bimble to stop giving boaters a discount for BACS payments. Pretty strange behaviour for someone who’s supposed to be on the side of boaters. 

 

If you really want to use a Facebook group for 12V advice then you’ll get the best info from the original ‘12V Boating Group’ without any of Graham Mill’s BS. 

Edited March 9, 2019 by Athy
To remove a personal insult, after reports.

[Markinaboat]

On 05/03/2019 at 18:42, WotEver said:

No he doesn’t. Wrong group.

 

Graham Mills ihas some VERY odd ideas. He left this forum in disgrace, moved to TB and was seen through there quite quickly and left there too. He eventually ended up on the ‘12V Boating Group’ on Facebook which is owned and run by Phil Brooke-Little. In July last year Phil had finally had enough of him and blocked him from the group. GM then set up the similar-sounding ‘12V Boating Group Graham and Others’ which has less than a third of the members of the original. 

 

The last I heard about Mr Mills was that his latest crusade was to attempt to bully Bimble to stop giving boaters a discount for BACS payments. Pretty strange behaviour for someone who’s supposed to be on the side of boaters. 

 

If you really want to use a Facebook group for 12V advice then you’ll get the best info from the original ‘12V Boating Group’ without any of Graham Mill’s BS. 

Wow, all very damning. He is quirky but have found him very helpful and eager to please. But thanks for putting me straight on the groups etc. I've always wondered what the 'Graham & Others' was all about!

Edited March 9, 2019 by Athy

[WotEver]

12 minutes ago, Markinaboat said:

have found him very helpful and eager to please

Yes he is. But you will note that he NEVER admits when he’s wrong and unless he’s changed considerably in the last 8 months he’ll be wrong quite often. He’s retired and bored and his group gives him an interest. 

 

How often has he recommended a Cyrix VSR in the last month?

 

 

[Guest]

On 05/03/2019 at 18:42, WotEver said:

No he doesn’t. Wrong group.

 

Graham Mills has some VERY odd ideas. He left this forum in disgrace, moved to TB and was seen through there quite quickly and left there too. He eventually ended up on the ‘12V Boating Group’ on Facebook which is owned and run by Phil Brooke-Little. In July last year Phil had finally had enough of him and blocked him from the group. GM then set up the similar-sounding ‘12V Boating Group Graham and Others’ which has less than a third of the members of the original. 

 

The last I heard about Mr Mills was that his latest crusade was to attempt to bully Bimble to stop giving boaters a discount for BACS payments. Pretty strange behaviour for someone who’s supposed to be on the side of boaters. 

 

If you really want to use a Facebook group for 12V advice then you’ll get the best info from the original ‘12V Boating Group’ without any of Graham Mill’s BS. 

Phil Brooke Little is a top guy. Helped me loads when fitting solar for the first time, and his advice was spot on.  Not a huge farcebook fan, but Phil's site is really good.

Edited March 9, 2019 by Guest

[WotEver]

1 minute ago, catweasel said:

Phil Brooke Little is a top guy. Helped me loads when fitting solar for the first time, and his advice was spot on.  Not a huge farcebook fan, but Phil's site is really good.

Yup, he’s a good guy. Usually jumps in on most threads. 

[Markinaboat]

23 minutes ago, catweasel said:

Phil Brooke Little is a top guy. Helped me loads when fitting solar for the first time, and his advice was spot on.  Not a huge farcebook fan, but Phil's site is really good.

I couldn't find his 12v group on FB.