Thetford Fridge

[Walkingmox]

We have changed from our lovely Burstner motorhome with a 3 way fridge to a camper van with a Thetford electric only fridge. Although we have a rooftop solar panel which runs the leisure battery and thus the fridge in grey weather or parked in the shade to keep cool will it produce enough to avoid using a campsite in order to plug into the electric. Sited just inside the sliding door ie: in the sun we need to run it on high to keep the freezer cold which seems to produce ice build up at the internal back wall and when this defrosts there doesn't seem to be an adequate well under the salad drawer to catch the ice so it floods the floor and carpet outside. we have never had any problem before. are we doing something wrong. can we wild camp and still run the fridge. Sorry lots of questions

 

[wildebus]

To get a meaningful answer, you need to provide more information.

You have a solar panel. How large?
You have a leisure battery. What size and type?

 

[merl]

We have changed from our lovely Burstner motorhome with a 3 way fridge to a camper van with a Thetford electric only fridge. Although we have a rooftop solar panel which runs the leisure battery and thus the fridge in grey weather or parked in the shade to keep cool will it produce enough to avoid using a campsite in order to plug into the electric. Sited just inside the sliding door ie: in the sun we need to run it on high to keep the freezer cold which seems to produce ice build up at the internal back wall and when this defrosts there doesn't seem to be an adequate well under the salad drawer to catch the ice so it floods the floor and carpet outside. we have never had any problem before. are we doing something wrong. can we wild camp and still run the fridge. Sorry lots of questions

On the back wall.of the fridge towards to bottom you should see a shaped recess that catches condensation as it runs down the rear wall, this recess has a hole and a drain tube which diverts the water away, this pipe can get blocked and then the water can't drain away and eventually ends up at the bottom of the fridge and then spills out of the door. A bit of wire or a pipe cleaner down the drain hole and pipe is probably all you need to do.
WRT the ability to use the fridge off grid, that will depend on many factors, batteries, solar, amount of driving/ charging pre park up, length of time off grid, amount of sun, time of year etc not to mention how much other equipment you use on 12v while off grid.

 

[Walkingmox]

thanks for the tip with the pipe cleaner . it's dark now but I'll check in the morning ands I'll also look up the size of the battery and solar panel. I should know these things but as we didn't previously have a solar panel it's all new to us. In the Burstner we had 2x leisure batteries and now we only have the one we could also choose to run our fridge on gas. I guess we will only find out by experimenting. Our new campervan is a Malibu

 

[Canalsman]

Not directly related but I have a Thetford absorption fridge installed in my 2007 Autotrail Dakota.

I've owned it since 2015 and I've long had oveflow problems with the drip tray below the condensor fins. There's a pipe that runs through the back of the fridge and empties into a small reservoir positioned over part of the fridge cooling circuit that gets quite hot. The water evaporates as a result.

Over the years I've repeatedly cleared the pipe with a length of wire to get rid of accumulated grot.

A few weeks ago this process stopped working and I couldn't work out why.

Upon closer investigation I discovered that a plastic plug was inserted in the end of the pipe at the reservoir end!

I assume that this should have been removed back in 2007 when the fridge was fitted...

 

[Walkingmox]

That’s interesting. I’ve obviously got a lot to investigate today including the solar panel about which I could find absolutely nothing in the paper work.

 

[Pudsey Bear]

Parking in the shade to keep it cool sort of defeats the solar aspect of the setup I think.

 

[merl]

That’s interesting. I’ve obviously got a lot to investigate today including the solar panel about which I could find absolutely nothing in the paper work.

If you can measure the approximate width and length the output can be calculated from that.

 

[Pudsey Bear]

Doesn't each square tile of the panel equal the same regardless of newer types as well Merlin?

 

[Robmac]

Regarding the fridge, which I assume is a compressor type, the following article may help;

How Long Will a 100Ah Lithium Battery Run a 12V Fridge?

Discover how long a 100Ah lithium battery can power your 12V RV fridge. Learn simple methods to calculate runtime and tips to optimize your energy use for extended trips.

www.redodopower.com

Factor in what you will be running alongside it as well.

Personally, I have been running 2 x 6V 240AH batteries in Paralell which doubles the voltage to 12V and keeps the AH to 240. I can run our Vitrifrigo fridge for 3-4 days alongside using lights, pumps Etc. without needing EHU or alternator power. That is with a 100W solar panel up top.

However, there's always a bit of power anxiety involved which is why I'm upgrading to 2 x 300AH Lithium batteries and 850W of Solar, but then I will also be using a lot of 240V via an inverter.

It would be worth measuring the space you have for batteries for any upgrades you may consider but get the most out of what you have already and see how it goes.

 

[merl]

Doesn't each square tile of the panel equal the same regardless of newer types as well Merlin?

Yes, as long as the squares are the same size. Ultimately 220W per square metre (of actual black panel) will be close enough for jazz. The cheapest Chinese flexible panels are a big chunk less I've found.

 

[merl]

Regarding the fridge, which I assume is a compressor type, the following article may help;

How Long Will a 100Ah Lithium Battery Run a 12V Fridge?

Discover how long a 100Ah lithium battery can power your 12V RV fridge. Learn simple methods to calculate runtime and tips to optimize your energy use for extended trips.

www.redodopower.com

Factor in what you will be running alongside it as well.

Personally, I have been running 2 x 6V 240AH batteries in Paralell which doubles the voltage to 12V and keeps the AH to 240. I can run our Vitrifrigo fridge for 3-4 days alongside using lights, pumps Etc. without needing EHU or alternator power. That is with a 100W solar panel up top.

However, there's always a bit of power anxiety involved which is why I'm upgrading to 2 x 300AH Lithium batteries and 850W of Solar, but then I will also be using a lot of 240V via an inverter.

It would be worth measuring the space you have for batteries for any upgrades you may consider but get the most out of what you have already and see how it goes.

From previous posts from many users It seems that a decent rule of thumb is 50Ah/day, so a 100Ah battery will give you potentially 2 days of fridge use. This of course assumes 100 actual Ah so a half knackered lead acid battery is going to give you way less, and you have to account for anything else you're using in the van. Then you can start calculating and adding the gain from solar panels but of course they need sunshine and although you can guestimate sunshine you can't guarantee it

 

[Walkingmox]

We can't find any information on the solar panel except that it measures 9x4 squares ie 36 squares but my husband has measured it as 54cmW x 120cmL

 

[Pudsey Bear]

You can measure the volts and amps to find the wattage.

 

[Walkingmox]

The fridge is a Thetford T2090

 

[merl]

We can't find any information on the solar panel except that it measures 9x4 squares ie 36 squares but my husband has measured it as 54cmW x 120cmL

Allowing for the border that'll probably be a 120W panel.
In full sun in the summer you'll probably get 100W so you'll need about 6 hours or so of full sun to recover enough solar energy to run the fridge for 24hours including the evening when you're not getting any sun at all. To this you'll need to add anything else you use like TV, phone/laptop charging, lighting etc.
I'm sure you can now see that in glorious summer weather and not parked in the shade you'll probably be fine, if you know of such WC places with guaranteed sunshine please list them here so we can all access them!!

 

[Walkingmox]

High-tech compressor performance​

Thetford have expanded on the already-popular performance of the T1090, finding big efficiency gains with the T2090. The fridge's battery efficiency gives you an incredible 8 days (on 2 x 95 Ah batteries), making it perfect for extended off-grid trips. The display has been upgraded to a modern capacative touch screen, allowing you to easily switch between operating modes. The Thetford T2090, for example, includes a Night Mode function, which reduces the noise of the fridge to a whisper, letting you get a good night's sleep. These features can also be controlled via the latest campervan, motorhome and caravan control panels, thanks to the inclusion of CI-BUS compatibility.

Thanks for all your help. I have run this (above) off the internet which seems to suggest that the fridge itself has 2x batteries that will run for 8 days? I wonder! I have also read through your link Robmac which seems to suggest 3 days so it's back to not worrying and try it. Yes park in the sun and hope for the best. We checked behind the drip tray and sure enough there is a little plug but it isn't mentioned anywhere in the manual. The manual does suggest rotating the storage lock in order to leave an air gap for over winter storage but our storage lock is fixed unless I get the screws out ?

 

[Walkingmox]

There's a wonderful CP at the back of the beach in Ettrick Bay on the Isle of Bute that I would recommend but nowhere seemingly on the island to empty the toilet unless you actually stay at a campsite.

 

[merl]

which seems to suggest that the fridge itself has 2x batteries that will run for 8 days?

No, the fridge doesn't contain ANY batteries, the bumf is saying it'll run for 8 days IF you have 190Ah of PERFECT batteries in your van AND those batteries are powering JUST the fridge AMD you discharge those batteries to 100%, There WILL be a degree of exaggeration in their bumf too.
If you've got old Lead Acid batteries you'll likely only get a small proportion of their suggested capacity I'm afraid.

 

[merl]

Theory and practice often don't align I'm afraid.