Solar panel cant keep up

[billyfish]

So, not on my boat but in a small camper, I've got a 60w panel attached to a 70ah leisure battery and running a small cheapy halfords cool box which is 40w. But it can't keep up even in this continuous sunshine we're having in the UK just now. I am stumped with this stuff. On the boat I have a proper fridge, a much smaller panel but 2 decent 110ah batteries doesn't seem to get that low.

 

[noelex]

The non compressor, Peltier fridges/cool boxes use a great deal of energy for only a small amount of cooling.

It will be 40w continuous 24 hours a day which is much more energy than a 60w panel can deliver.

 

[lustyd]

40x24=960Wh for the fridge on a hot day
60x6=360Wh on a good clear day if you point it at the sun with no shade.

 

[PetiteFleur]

With a compressor fridge it will use less energy - that's what we have in our motorhome, actually an 80w panel as couldn't get the 60w panel we wanted.

 

[LiftyK]

My 120W panel plus 110Ah domestic battery easily allows 24*7 compressor fridge operation.

 

[geem]

The non compressor, Peltier fridges/cool boxes use a great deal of energy for only a small amount of cooling.

It will be 40w continuous 24 hours a day which is much more energy than a 60w panel can deliver.

My cheapo Peltier cool box used 70w. Useless unless plugged in to a running car

 

[noelex]

My cheapo Peltier cool box used 70w. Useless unless plugged in to a running car

Billyfish indicated in post 1 that his unit had a 40w rating.

Peltier heat pumps come in various sizes and wattages and some cooling boxes use two or more devices. So cooling boxes may have a higher or lower consumption despite fundamentally using the same Peltier technology. However, they always have a limited amount of cooling ability and use far more power than a conventional compressor fridge would for the same amount of cooling. 70w is not unusual for some units.

 

[Refueler]

40W ... that's nothing !! My Peltier box draws over 8A continuous on 12v .... I had to fit a relay so that it switched on when engine ran ... switched off when engine stopped. Manual says 70W ... but that's optimistic rubbish !!

Finally gave in and bought a proper fridge box !!

The old box will double now as storage of that days items after being in fridge box.

 

[geem]

Billyfish indicated in post 1 that his unit had a 40w rating.

Peltier heat pumps come in various sizes and wattages and some cooling boxes use two or more devices. So cooling boxes may have a higher or lower consumption despite fundamentally using the same Peltier technology. However, they always have a limited amount of cooling ability and use far more power than a conventional compressor fridge would for the same amount of cooling. 70w is not unusual for some units.

I know. We only used it in the car when driving to the in the UK boat many years ago. They have no place on a boat. Prehistoric energy chompers like tungsten filament light bulbs

 

[billyfish]

That's it then. New coolbox with a compressor. Any recommendations?

 

[Refueler]

Waeco / Dometic are good but found prices a bit high ... so I went Vevor 40L portable refridgerator

Simply does what it says it should do ! And a lot less power needed once temp is reached ..

 

[Pete7]

That's it then. New coolbox with a compressor. Any recommendations?

Yes, Alpicool. We have the 20L version which can be used as a freezer or fridge. 1/3rd of the price of a Domestic type. As a fridge uses the same as our coolbox and compressor fridge.

https://www.amazon.co.uk/Alpicool-R...:Alpicool&s=automotive&sr=1-4&ts_id=303615031

 

[Refueler]

Waeco / Dometic are good but found prices a bit high ... so I went Vevor 40L portable refridgerator

Simply does what it says it should do ! And a lot less power needed once temp is reached ..

Points to consider :

Is it better to have wheels or just handles ? My 40L is with handles only - reason its slightly cheaper than the wheelie version. It means that it will be heavy if filled before placing on boat.

Do you want a split box ... you can have box that has fridge and freezer sections - but this reduces your volume of course. I went for single volume box - that can be fridge or freezer

Overall size of box ... AND VERY IMPORTANT .... which orientation is the lid opening .... where are controls ....

The above meant quite a lot of checking out websites to get right setup.

 

[noelex]

For what its worth, we have two on our current boat. A National Luna and an Engel. Both have been 100% reliable over 5 years use.

The National Luna model is beautifully made with a stainless steel exterior, a smooth one piece anodised aluminium interior (no coils to damage) and is obviously a quality product. The Engel is much cruder, but they have different type of compressor to all other fridges (a swing compressor) and they have a reputation for exceptional durability. We sail in some remote places where repair/replacement would be difficult so these more premium brands make sense in our case, but would be overkill for most applications.

There are many much less expensive fridges and despite the lower price tag even the "no name" knock offs seem to have a long life and offer great value for money. Most owners seem very happy no matter what the brand.

One of the advantages of this type of fridge (or freezer) is that unlike traditional boat fridges it is cheap enough that if it does break and you cannot fix this yourself, it can be thrown away and replaced with a new unit so there is some sense buying the least expensive unit, especially if someone recommends a brand that has been reliable, just make sure it is a proper compressor fridge.

 

[wingcommander]

+1 on the Engel , MR 40 litre model , had it running 5 Summers. Basic as in no internal light ,no thermometer display ( I have a clip on thermometer on the internal basket) ,not totally silent when the Sawafuji swing compressor kicks in .
However it will run on 12vdc or 240ac though never needed the latter, and a 2.5amp draw at circa 12 volt for around 20 min in each hour . ( yes I have sat noting its cycle whilst awaiting tides lol ) means its one of the least amp guzzlers. They ain't cheep though !

 

[lustyd]

Waeco / Dometic are good but found prices a bit high ... so I went Vevor 40L portable refridgerator

Simply does what it says it should do ! And a lot less power needed once temp is reached ..

They pretty much all have Secop (formerly Danfoss) compressors anyway so the main difference will be design and packaging.

 

[Refueler]

They pretty much all have Secop (formerly Danfoss) compressors anyway so the main difference will be design and packaging.

And price !!

My 40L Vevor from Polish dealer was 230 euro incl del

https://www.aliexpress.com/item/100...o.order_list.order_list_main.5.29881802DtAFid

Now price is up as it was special deal at the time ....

 

[Refueler]

+1 on the Engel , MR 40 litre model , had it running 5 Summers. Basic as in no internal light ,no thermometer display ( I have a clip on thermometer on the internal basket) ,not totally silent when the Sawafuji swing compressor kicks in .
However it will run on 12vdc or 240ac though never needed the latter, and a 2.5amp draw at circa 12 volt for around 20 min in each hour . ( yes I have sat noting its cycle whilst awaiting tides lol ) means its one of the least amp guzzlers. They ain't cheep though !

Just out of interest .... how do you set your temp ?

My Vevor even though one of the cheapest - has a display to set temp via the +/- buttons - then after a few secs it reverts to show actual internal temp ...

 

[wingcommander]

It has a green neon to prove a 12v supply, and just a single twist dial for temp control. I must admit not the most convenient, however once you get used to a pre set position its pretty accurate. Turned to max its -18 Celsius. The rest of the range is guess work. It was my only real gripe until I got acquainted with this control.

Just out of interest .... how do you set your temp ?

My Vevor even though one of the cheapest - has a display to set temp via the +/- buttons - then after a few secs it reverts to show actual internal temp ...

 

[geem]

And price !!

My 40L Vevor from Polish dealer was 230 euro incl del

https://www.aliexpress.com/item/100...o.order_list.order_list_main.5.29881802DtAFid

Now price is up as it was special deal at the time ....

In the USA you can get a 50 litre with secop compressor for $220. I have the same one as 42 litre. I wish I had bought the 50 now