How much power do we need?

We have a 1kva Yamaha gen set and 150 watt sola panel.
They won't handle a small fridge and and iPad.
Can someone help with what we need please.
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Reply By: The Bantam - Sunday, Oct 30, 2016 at 11:32

Sunday, Oct 30, 2016 at 11:32
A bit more infoirmation would be helpfull.

What are you trying to achieve

Are you day tripping or do you want to stand up indefinitely without mains power?

Caravan camper, tent camp or all in the vehicle?

What fridge? Run as a fridge or freezer ... or is it a combined uint?

Compressor fridge or an absorbtion fridge?

other electrical demands?

AnswerID: 605514

Follow Up By: Annie N - Sunday, Oct 30, 2016 at 12:46

Sunday, Oct 30, 2016 at 12:46
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
FollowupID: 875267

Follow Up By: The Bantam - Sunday, Oct 30, 2016 at 14:36

Sunday, Oct 30, 2016 at 14:36
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.

FollowupID: 875269

Follow Up By: Annie N - Sunday, Oct 30, 2016 at 16:53

Sunday, Oct 30, 2016 at 16:53
Many thanks for all your knowledge've been a great help!

FollowupID: 875275

Follow Up By: The Bantam - Sunday, Oct 30, 2016 at 17:22

Sunday, Oct 30, 2016 at 17:22
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.

FollowupID: 875279

Reply By: pop2jocem - Sunday, Oct 30, 2016 at 11:39

Sunday, Oct 30, 2016 at 11:39
Hi Annie,

A few years ago we went camping with my son and his family. I had our caravan and at the time he had a camper trailer. Between us we had 2 40l Engels, 1 Waeco about the same size, and our 3 way fridge in the van, plus a bit of lighting for the van and camper. We had all the fridges running on 240 volts.
I took my Honda 2.0 and he had a Honda 1.0. The 2.0 ran everything and hardly got above idle.
We tried his 1.0 and although it was reving a lot harder, it carried the load.
So maybe you need to determine what amps your equipment is needing by doing a calculation of the wattage requirements of everything added together.
If all that adds up to a figure the Yamaha's continuous rating is or less then maybe get the genny checked out.
You also mention a 150 watt sola panel. Are you using this to charge a battery, and are you using the genny to charge that same battery?
If you are running a 3 way fridge off 12 volts they will draw an amperage that may be well in excess of what your genny and panel can supply.
Maybe a bit more detail about how you are running your appliances.

AnswerID: 605515

Follow Up By: Annie N - Sunday, Oct 30, 2016 at 12:58

Sunday, Oct 30, 2016 at 12:58
Thanks for your reply Pop....I have just supplied more details to Bantam? Gen and solar run everything.
FollowupID: 875268

Follow Up By: pop2jocem - Sunday, Oct 30, 2016 at 16:54

Sunday, Oct 30, 2016 at 16:54

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.

FollowupID: 875276

Follow Up By: Annie N - Sunday, Oct 30, 2016 at 17:05

Sunday, Oct 30, 2016 at 17:05
Hi Pop....great advice and really appreciated.
FollowupID: 875277

Reply By: RMD - Sunday, Oct 30, 2016 at 13:31

Sunday, Oct 30, 2016 at 13:31
Annie N
Are you trying to charge a battery with the generators 12v output? if so forget that as it requires the generator to run at full speed to make some current for battery charging.
Far better to use a proper 240v to 12v battery charger with a decent output current rating to top up batteries. That should allow TV/DVD and the I devices to be charged from the battery.

Does your solar system have large sized leads from panel to regulator and battery or the one supplied with a panel. Usually most people have to increase/replace the cables so voltage drop is minimized and solar energy can be effectively put into the battery.

The 1KVA generator should run the fridges ok as long as they aren't started simultaneously. They draw close to 500 watts but the gen possibly can't handle the start loads of both fridges at the same time. Just a management issue with the available power.

Not sure what you meant by they, the gen and solar won't handle the system.
The solar won't do anything for the fridges because they are dedicated 240v AC.

There must be a battery in the system but you haven't mentioned it and how it is used with the solar so the comments are based on info gleaned from the post.
AnswerID: 605521

Follow Up By: Annie N - Sunday, Oct 30, 2016 at 15:02

Sunday, Oct 30, 2016 at 15:02
WHEW! Guess I need to get a electrician to look at 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.
FollowupID: 875272

Reply By: Notso - Sunday, Oct 30, 2016 at 14:12

Sunday, Oct 30, 2016 at 14:12
Have you got a Hot Water Service in the van??

Are you plugging the Genset into the vans input plug?

If so there are a things that will draw power from the 240 volt system. A hot water service is around 900wats, the charger for the house battery in the van, if you have one will use some power as well.
AnswerID: 605522

Reply By: swampy - Sunday, Oct 30, 2016 at 14:21

Sunday, Oct 30, 2016 at 14:21
fridge freezer running via invertor from a battery charged by gene and solar ???
Need way more info on the entire system ..

AnswerID: 605523

Reply By: rumpig - Sunday, Oct 30, 2016 at 17:31

Sunday, Oct 30, 2016 at 17:31
As mentioned by Tomo and others above, you need to supply some more precise info for them to understand exactly what set up you are running for them to be of any real help.
What size battery / battery bank are you running this all off of, and what's it in? .....i'll assume there's one or several batteries located in the van somewhere, but we don't know what you have and what size they are.
How do you charge that battery bank exactly? As in yes you have a generator and solar, but when using the generator is it charging the battery via a seperate 12V charger running from the genny's 240V power, or are you using the 12V charge section that is on the genny itself? Do you just plug the power lead from the genny into the vans 240V power supply and charge it via a charger fitted in the van, if so what size charger is it?
How is the solar connected to the van for charging / via what charge controller system etc?
if you can answer those questions, people will be able to give better answers to help you out. At the end of the day, running 240V fridges and freezes from a battery set up is not a fantastic set up, to get a simple understanding of why have a read of this link, and remember that's for a fridge that uses less power then a freezer would do.
AnswerID: 605526

Reply By: Member - Phil G (SA) - Sunday, Oct 30, 2016 at 20:01

Sunday, Oct 30, 2016 at 20:01
Hi Annie,
The Westinghouse 240V fridge and freezer are the problem. They are not suitable for caravanning on the move.
They will only be usable when you are stationary and connected to 240V power. So there is no way you can run them when driving.

Most caravanners use a 3-way fridge - so it can run on 12V when driving, LPG when off grid and 240V when you have access to power. You don't need a generator if you have one of these.

The other items - Ipod, chargers, LED lights are easily managed with your 150W solar panel, regulator and a battery in your caravan. And a 12V charger helps when you have access to 240V so you can ensure the battery is fully charged.

I hope this is not confusing, but I'm thinking of a workable solution if you want to live off-grid.
AnswerID: 605536

Reply By: Motherhen - Sunday, Oct 30, 2016 at 23:52

Sunday, Oct 30, 2016 at 23:52
Hi Annie

Without all the technical stuff, when we bought an old camper, we removed the gas fridge and replaced it with a small 12 volt compressor fridge of the same dimensions. Adding a 100 ah battery and getting an 80 watt solar panel to use as a portable when stopped, plus a trickle feed from the tow vehicle, we had enough power for the fridge and a couple of lights. We decided to try it, leaving the generator at home. This would not be suitable for all weather camping.

We now have a caravan with 4 x 125 w solar panels feeding 4 x 110 ah batteries, running a small caravan fridge, an Engel car fridge as a freezer, water pumps, lights, computers, battery chargers, and a 12 v fan in hot weather. We have plenty of power in any weather conditions.

Somewhere in between would suit most campers.

Better to have more silent solar than a generator which you cannot use in most national parks and will have restrictions in many other campsites.

Red desert dreaming

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AnswerID: 605542

Follow Up By: Annie N - Monday, Oct 31, 2016 at 10:00

Monday, Oct 31, 2016 at 10:00
Sounds good mother hen...thanks!
FollowupID: 875294

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