power supply

Submitted: Monday, Aug 22, 2005 at 14:45
ThreadID: 25789 Views:2316 Replies:3 FollowUps:5
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hello......this would have been talked about heaps i know......sometimes there is too much info on here to find what your after.....We live in nth qldand trying to decide which power souce would be best for us.....we need to run a 12/240 fridge/freezer.still to buy...depending on what i read here...size ....50-60. Not so worried about the light situation, but would like something we might be able to run a fan.....12 and/or240, becourse of our heatwe camp anywhere from 2 nights t0 a week without power.............thanks......
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Reply By: Member - Roachie (SA) - Monday, Aug 22, 2005 at 15:35

Monday, Aug 22, 2005 at 15:35
G'day Tildo,
You'll get 2 basic schools of thought on this subject......... Generators & Solar Panels.

I went with a very quiet Yamaha gen set (1kva). It honestly doesn't disturb anybody, cos we only run it about every 2nd day and only for a few hours during the day when there is usually a fair amount of other camp-site "noise" anyway. I use a 30 meter long extension cord, stick the genie behind a tree and unless you go over to check the petrol level etc, you'd hardly know it was there. It also has the added benefit that it can run your fridge (if it's a true 240 volt unit, like our 2 Engels), while it also charges your battery/ies and can also be used to run a decent sized drill, grinder or whatever.

Solar is also great; but i decided it didn't suit our particular needs. The panels seem to be more difficult (in my case) to find a place to carry; you really need to be re-pointing them every hour or 2 if you want to get best benefit/s; get a few cloudy days and their output is seriously compromised; only good for charging your battery/ies....so you still need to run your fridge/s off the batteries while you're trying to charge them up; result is that the solar panel/s are probably only putting back in the same amount of juice the fridge is also sucking out during the day.

Just my thoughts.....I know Jimbo has posted quite a lot of his successful findings regarding solar panels earlier this year; he was rapt in the way his system works and I am very pleased for him.

Good luck

Roachie
AnswerID: 126304

Follow Up By: Mainey (WA) - Monday, Aug 22, 2005 at 18:18

Monday, Aug 22, 2005 at 18:18
Tildo,
As Roachie has stated Jimbo has posted various positive results, because he also actually knows how to use his Solar system, he now understands how they work and he also knows of any limitations.
Solar panels only need to be re-positioned every hour or 2 if you want to get 100% charge, and not many people I have ever met in the bush worry at all, mine sits flat on my vehicle 24/7 and is permanently recharging the Aux batteries; when you get a few cloudy days their output is not seriously compromised because my Solarex panel actually work better in mild cloud cover than in bright sunlight due to the reduction of panel temperature; They are a fantastic device for charging your batteries because there is no extra fuel to carry or set-up regime to follow and you are not having to look after them all the time from the light fingered folk.
you can be sure they are working all the time with the addition of a decent Solar Regulator with an LCD screen to show you what you have used and what is being produced and going into the Aux batteries....
You run your fridge off the Aux batteries while you're charging them; result is that one large solar panel is probably putting back in AT LEAST the same amount of power the fridge is using, and after all that is all that is required of them.

Do the numbers, I believe Engel uses ~1.8 A/h and cycles on/off, so off time is using no power, and one large panel puts out at least 3.7 Amp continuously for AT LEAST four hours daily, down South, more up North, even if you loose ten amps in 24 hours, how many days will you still have a viable battery system before you go for a drive to get food or water.
Hypothetically
Fridge draws ~2 amps x 14 hours/day = 28 Amps used.
Panel delivers 4 amps x 6 hours = 24 Amps to the Aux battery daily = 4 Amp loss
Panel delivers 4 amps x 4 hours = 16 Amps to aux battery daily = 12 Amp loss
That’s using only 4 hours of sun, for comparison my panel starts putting power back into the Aux batteries from just after sun-up till almost sun-down, yes the early/late numbers may be smaller but they all add up to often well in excess of 30 amps daily.

Then you have to consider the problem of camping in National Parks as Generators are not permitted to be used in them at all, and often when you have to camp in close to existing campers and they see your genny and ask you not to camp so close because they are there for the tranquillity... what will you do then to recharge your batteries?

You will get really good sounding advice from all and sundry, however those who have no problems with their solar system will tell you they are terrific and likewise those with a genny will passionately tell you they have the answer, the places where you camp may define your choice of a battery charger for the outback.
As you can see there is for and against for both options.
Those without either system are telling you what you already know :-(
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FollowupID: 380955

Reply By: Jimbo - Monday, Aug 22, 2005 at 17:23

Monday, Aug 22, 2005 at 17:23
Tildo,

You'll need a decent auxillary battery to start with. I'd recommend an AGM (Absorbed Glass Mat) battery; brands are Remco, Fullriver and Lifeline. They'll set you back between $250 and $400 for a 100 amp depending on brand and how well you bargain.

You'll also need an isolator (Redarc or similar) to isolate your start and aux batts, around $120. Then cabling and fitting. Talk to an auto elec, but expect around $750 all up for the dual battery setup.

The big advantage of AGM over wet cell is that they accept charge very quickly. This is particularly important if you go the generator route; you won't need to run the genny as long to recharge. If you do decide to go the genny, do like Roachie and get a good one. The voltage regulation with cheapies is poor, they can put out up to 10 volts which will "Wellington Boot" your battery.

Solar will work very well in NQ; I lived in Townsville for eight years and know just how sunny it is. I would recommend and Amorphous typre panel as they get more efficient the hotter it gets. A polycrystalline panel loses efficiency above 25 C, the loss is around 20% at 35C and you'll see plenty of that.

I get by in the Melbourne summer running an 80L Waeco off a Uni Solar 64 watt amorphous panel. The advantage of the AGM Battery is if it is cloudy and you're not getting enough charge, idling the car for 15 minutes 2 or 3 times a day is a backup. I've only had to this once in the Melbourne winter. I doubt you'll encounter that problem.

64 watt Uni Solar, plus regulator and cabling will be about $700.

As for fans, you can get those little 12volt car fans from K Mart for about $15 and they draw about 1.5 amps ie bugger all unless you run a lot for a long time. I'm guessing you only want to run them for a few hours at night.

Whether you go Solar or Generator is a personal choice. They both work.

You could get by with a genny and your start battery. Run everything from your start battery and keep it regulalrly topped up with the genny. It's not a route I would go as, if you regularly discharge your start battery, you run the risk of stuffing it quickly. If this happens, no amount of charging from a generator or solar will give ut enough charge to start your car and you will be stuck.

Hope this helps,

Cheers,

Jim.
AnswerID: 126316

Follow Up By: Jimbo - Monday, Aug 22, 2005 at 18:49

Monday, Aug 22, 2005 at 18:49
I said "The voltage regulation with cheapies is poor, they can put out up to 10 volts which will "Wellington Boot" your battery."

I meant up to 19 volts.
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FollowupID: 380960

Follow Up By: Brew69(SA) - Monday, Aug 22, 2005 at 18:57

Monday, Aug 22, 2005 at 18:57
Hi Jimbo, i used to think i needed an isolator too but now i just run the batteries in parallel. Advantage is extra running time for the fridge........... my waeco will actually stop running before i can't start the patrol. However in the unlikely event that it won't start i have my faithfull battery pack which i use for portable fluro lighting.
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FollowupID: 380961

Follow Up By: Jimbo - Monday, Aug 22, 2005 at 19:05

Monday, Aug 22, 2005 at 19:05
Stu,

Have you ever actually used your battery pack in anger?

Do they actually work on your motor. We have one in my wife's little car and tried to use it on our son's EF 4.0 L Falcon. It wouldn't even turn it over.
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FollowupID: 380965

Follow Up By: Brew69(SA) - Monday, Aug 22, 2005 at 21:28

Monday, Aug 22, 2005 at 21:28
Well i have not used it for jump starting no. What size was the one you tried using. Pesty has used his on his lads Commodore (i think) for quite a long time and said it works a treat. 900 amp pack
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FollowupID: 380984

Reply By: Mainey (WA) - Tuesday, Aug 23, 2005 at 11:31

Tuesday, Aug 23, 2005 at 11:31
Checked the solar panel output last night at 4.45pm
it was still putting out 0.5 Amp, however nothing was going into the Aux battery as it was fully charged @ 13.9v, as it was being charged all day due to the solar system.

Have checked again this morning at 7.50am and Solar system was putting out 0.2 Amps, with the full 0.2 Amps going to the Aux battery as it was only 12.7v due to it running accessories during the night, without being driven for a few days the only power being supplied from sunlight, not direct sunshine...at 7.50am this morning the sun was still not actually shining on the panel and it is still overcast.

It's now 9.20am and still overcast, the panel is still not in direct sunlight however the Aux battery is now 13.2v with 0.4 Amps produced at the panel and the full 0.4 Amps will be sent to the Aux Battery till it gets to 13.9v.
AnswerID: 126423

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