How much power do we need?

Bush camping with no mains power.
2 small seperate fridge and freezer near new. Westinghouse 121 pair
50hz. 120 litre. O.9amp fridge and 1.0amp freezer. Electric only
2 iPads
DVD player
all in caravan

Thanks for your help

First it must be understood that the domestic 240v fridges are an inefficient high demand item with high start currents. They will consume many times what a 12/24 volt compressor fridge will.

If you are at all serious about off grid camping these need to go.

I would expect your 1KVA generator should run them ...... but their high start currents and poor power factor may mean that it wont ... this will also be an issue if you want to run them off an inverter.

As it stands, in round figures you have around 600VA peak demand ....... because of the inefficiency of these fridges and one being a freezer I estimate your average demand to be around 300 to 400VA ...... in hot weather and particularly if you are chilling down, the freezer has to be calculated as running nearly continuously, the fridge will probably have a 50% duty cycle or worse.

If you where to reliably supply a 400VA demand on a continuous basis from solar in the northern parts of Australia you would need at lest 1200 to 1600 watts worth of solar panels and at least 3000AH of batteries if running on 12 volts.
that is calculating a 50% depth of cycle and a 48hour rain reserve.

Running similar sized 12 volt compressor fridges I estimate you would have a peak demand of less than 150VA and an average of around 100VA.

You solar requirement would become around 300 watts and you required battery capacity would be around 500AH.

get rid of the freezer all together and ya gona cut that by 2/3 again.

So unless you get rid of the domestic 240V fridges you will be running a 2KVA generator contuinuously.

When it comes to power, solar and batteries, being optomistic simply does not pay.

cheers

Many thanks for all your knowledge Bantam...you've been a great help!

Cheers
Annie

Yeh Annie .... new fridges will probably cost you less than what you would need to support the existing fridges.

Those existing fridges would have been fine for somene doing only park stays.

cheers

Thanks for your reply Pop....I have just supplied more details to Bantam? Gen and solar run everything.
Cheers
Annie

Annie,

If I have got a handle on this so far, you are running a fridge and a freezer which between them you state draw, in round figures 2 amps @ 240 volts????

You also have a couple of Ipads which I assume get charged as required, maybe a couple of times a day.

Then there is the DVD which I assume gets a run as required but maybe not continuously.

All of this is running on 240 volts????

What I am unclear on is how the 150 watt solar panel fits into the picture. I would imagine you are charging a 12 volt battery?????

So are you running an inverter somewhere in here to also supply 240 volts???
If this is the case remember that a 150 watt rated sola panel is only capable of providing it's rated ability under perfect basically laboratory conditions.

Just as a comparison I use my Honda 2.0 during extended power outages. It runs a 400 lt fridge freezer and a 300 lt chest type freezer, along with a few lights and barely raises a sweat. Would 1.0 Honda or Yamaha do it?? No idea, never tried, but we are talking about domestic units much much larger than what you have.

Going on the figures you have supplied the 2 fridge freezer units need around 500 watts, I think. The 1.0 Honda has an intermittent rating of 1000 watts and a continuous rating around 800 watts from memory. I would imagine the Yamaha would be similar. Going on that, you should be able to run them together. Starting together may be problematical. No idea without trying.
As for charging a couple of Ipads and using a DVD I would doubt the power requirements would be all that big but once again without seeing their ratings, I have no idea.

Cheers
Pop

Hi Pop....great advice and really appreciated.

WHEW! Guess I need to get a electrician to look at it...my brain is scrambled with all the tec stuff.
I thought it would just be a matter of a larger gen or more Solar. Panels. ??

Thank you everyone for your help.

Sounds good mother hen...thanks!