TheBackShed.com

Forum Index : Solar : newbie solar & portable fridges questions

Author

Message

bobt
Newbie

Joined: 26/12/2009
Location: Australia
Posts: 17

Posted: 02:25pm 02 Jan 2010

Copy link to clipboard

Print this post

g'day everyone,

Since i first posted in my previous post "newbie solar questions",
Iv sat down and thought about the answers you experts gave me.

Also iv been reading alot of forums these past few days
dealing with solar and camping and off the grid questions and windmills as well.

So this posting is about the fridge issue i mention in the first post.
I wont be worrying about running the bar fridge on solar

instead

Iv decided to buy one of the waeco fridges or something simular
I read on one of the specs was one of the products uses 12v/0.84 amps

I calculated that it uses 10.08 watts/ hour (i think thats correct)

So with a battery of 100AH that equates to roughly 2 days before
running out juice??

also will my 380 pure sine wave inverter be enough to run a waeco fridge?
and keep it going non stop for indefinately on solar??

as the solar panels i will be using will be around 100 watt panels.

I hope the 100 watts solar panels (which i reliase might only be around 80 watts
and averaging around 4.5amps/per hour)
should be sufficient to keep charging the battery or 2 or 3 batteries connected
to each other continiously.

I am also considering a small portable windmill later on down the track to suppliment the solar setup.

I hope some you guys can offer me some other advice for solar stuff.
I just want to cut my grid consumption by half and also take the solar stuff
with me when i go camping.

cheers
bob

Tinker

Guru

Joined: 07/11/2007
Location: Australia
Posts: 1904

Posted: 03:03pm 02 Jan 2010

Copy link to clipboard

Print this post

Bob, the first thing about deep cycle batteries you must take in (if you want them to last a while) is:
Your 100Ah battery gives you only 25 usable Ah before it must be recharged.

Its a bit like having a full 100 liter tank in your car but you are only allowed to use 25 liters before you must fill her up again.

Yes, it sounds crazy but that is how deep cycle batteries work. If you fully drain them they will last only a few cycles, if you use only 25% of the charge they last many hundreds of cycles.

You do not require an inverter to run your 12V Wayco fridge, run it straight of your 12V battery - its more efficient doing it that way.

On my little sailboat I have a very efficient boat fridge, perhaps a bit better than your Wayco. I have 140W of solar and 200Ah battery (2x100Ah) to run that and the instruments, stereo, boat lights. Works fine on sunny days but with cloud 2 days in a row I need to turn on the 12V generator to keep the batteries full.

The above may give you some ideas, for you it is perhaps better to start with one panel, one battery and one item connected to it. Observe how it performs over a week or so and you will know if your set up has the capacity to connect something else as well.

Klaus

Tim_the_bloke

Senior Member

Joined: 15/11/2009
Location: Australia
Posts: 105

Posted: 09:45pm 02 Jan 2010

Copy link to clipboard

Print this post

bobt said
Iv decided to buy one of the waeco fridges or something simular

Good on you. A 12V fridge will be much more efficient than running a 240V fridge through an inverter. Also, it won't stall on starting like many 240V ones will due to start up surge.

Barry T Coles

Senior Member

Joined: 30/07/2009
Location: Australia
Posts: 109

Posted: 09:58am 03 Jan 2010

Copy link to clipboard

Print this post

G'Day Bob
I've got a GS50 Waeco " decent size" and I can run that comfortably for 14 hours overnight & not have a problem starting the cruiser next day, also with the Waeco they will cut out at low voltage to protect the battery.

Cheers
Barry

I need to learn from the mistakes of others.
I dont have the time to make them all myself.

Print this page

To reply to this topic, you need to log in.