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Fridge on Solar
Posted: 20 Jun 2008, 03:27
by Dubwana
8) I'm setting up my "new" to me 1981 T25 for use in East Africa for Camping. So no 240V hook up for the electrics. I've got an old 3 way Electrolux fridge, I'm disconecting the gas as I have no way of testing it. So its the split charger which I'd like to back up with Solar Power. The fridge says its 100W so at 12 V that's 8.33A supply. So if I go out and buy a solar panel of a higher rating, will it run the fridge during daylight hours? I know the battery would be flattened if I tried to run it overnight, I tried my spare 63A battery and it goes for around 2 hours.
My concern is security, not every place we will go will be so safe... so the larger panel I put on, the more it draws attention to the vehicle and makes it more likely to be broken into. So smaller the better. But not so small that it doesn't work.
Anyone tried running a fridge off solar? Is it realistic or should I just run it off the alternator?
I'd appreciate any suggestions.
Dubwana
Posted: 20 Jun 2008, 04:58
by maxstu
HI Dubwana.
How's life down your way. Another beautifully sunny day I expect.

Lucky man
A bit too early for any replies from the usual mob. Wait til they've had their boiled and toasted soldiers then prepare for an avalanche of pertinent replies.
Me? I know nothing and am off to bed.
My weekend starts here

Posted: 20 Jun 2008, 07:21
by tonytech
Running a fridge on 12 for long periods of time is not recomended, there is no thermostat, so the fridge will ice up, That said, some one on here built a thermostat circuit (have a search)
A 100W solar pannel will only give that output in ideal conditions (should be ideal in your part of the world) and will set you back £500 or so,
Others with more experience will wander by later.
T
Posted: 20 Jun 2008, 08:25
by kevtherev
best one I could find....
ALDEN KITECO 100W SOLAR PANEL KIT C5411
These 100 watt solar panel kits are for people who want high quality solar panels at a competitive price. With mono-crystalline cells fitted in metal frames, they are ready to mount on vehicles or boats.
Alden recommend fixing them with Sikaflex adhesive and this is included. A regulator and wiring also come with the kit.
* 1350mm L x 575mm W x 80mm H
* Weight: approx. 18Kgs
* Max. nominal output: 8 Amps per hour
most solar panels above 150 watts are 18volt or 24 volt
Mitsubishi seem to be the market leaders in these things
Posted: 20 Jun 2008, 10:24
by Dubwana
Thanks for those quick replies. I can see already that what I was thinking isn't so practical for my needs as it would result in a great big thing on the van which is not what I need. So.... is it possible to trickle charge the battery while I'm using the fridge to lengthen the time that the battery will last OR possibly, and probably more realisticly, to charge it up during the day so I can run it for a couple of hours in the evening/morning to cool down beverages etc.
If it's the latter, how small (and inconspicious) a panel could recharge a battery in a day of decent sunshine.
I have a feeling I'm clutching at straws as I ask this but if anyone can guide me through this so I don't chuck out money on something impractical I'd appreciate it. It may be best to get it cold on 240V before I leave home, run it on the alternator on the way and be happy with that...
By the way if it makes anyone feel any better, its the short rains right now so its chucking it down every day in tropical torrents.
Thanks again,
Dubwana
Posted: 20 Jun 2008, 10:43
by 1664
Why not just reconsider the gas option? By far the easiest provided you can get hold of gas out there.
Posted: 20 Jun 2008, 10:46
by toomanytoys
Would be either better to get the gas side sorted or replace the fridge with a new one..
12v while driving.. gas while stopped.. or fit 2 or 3 extra batteries to run it for a bit when stopped.. or get a small cheap generator to run it on 240..
Solar, costly and fragile.. not ideal...
Posted: 20 Jun 2008, 10:52
by 1664
The camper I hired in NZ had an electric only fridge but it wasn't an absorption type like we have, it was a compressor driven unit like you have in the house and had a very low power consumption, easily little enough for overnight running etc. Don't know if you can get them over here though....
Posted: 20 Jun 2008, 12:46
by toomanytoys
Yes you can, but they aint cheap...

Posted: 20 Jun 2008, 13:06
by AngeloEvs
We ran a Waeco Compressor fridge on a 120W solar panel during a long tour of Greece, Spain and Crete where temperatures soared to 40. The compressor types are expensive but they are far more energy efficient and freeze. Neither are they affected by gradient. The problem in high temperatures is that you want to park in the shade, I eventually removed the solar panel and set it up away from the van on a make shift frame. Didn't bother with the 3 way fridge unless we were on hook up, it barely cooled on gas. All the best with the trip and you might consider a portable 800W generator. It was one item that I wished I had taken.
Posted: 22 Jun 2008, 04:06
by Dubwana
Thanks for your help. I'm going to live with it on 240/12 V and if I ever want more I think the small generator option is the most practical. Certainly don't like the idea of having to park in the sun to get cold drinks. Seems to defeat the purpose. Thanks again. Dubwana
Posted: 22 Jun 2008, 07:15
by Headley18
Just another angle. If you want to go down the solar panel route, try running an inverter off your leisure battery (charged by solar) then run the fridge on 240v from the inverter. I'm not sure what the draw would be but might be worth a test.
We run a TV and play station (OK! low draw) off an inverter and it last around 8 hours continuous play on a 85amphour battery.
Posted: 22 Jun 2008, 13:39
by lloyd
12v running 12v heating element is much more efficient then inverting 12v to 240v to run 240v heating element cus inverter uses power to do the conversion to 240v. Heating elements are probably same wattage.
http://www.fridge-and-solar.net/fridgetest1.htm is a test of 12v inverted to 240v compressor fridge vs 12 compressor fridge.
Batteries don't stand a chance of keeping up on a 3 way fridge in hot weather.... in any weather. You need to use gas or change fridge for a compressor one. I had a compressor one in camper years ago... not chest kind.. and found in 30+ heat a 130amp battery would last 24 hours. Part of reason is constant getting in and out dumps cold out bottom of door every time door is opened and hot air displacing it has to be cooled when door is closed again.
Engel makes very good chest fridge/freezers. You might consider using one of them as a freezer, and using cool packs in a cooler for unfrozen goods and drinks.
http://www.4x4store.com.au/Portable-Fri ... 12960.html