Solar help

gst · Senior Member

Solar help

Cruising Cruze · Guru

G'day to you lovely people

I have an question abouth the solar power

we would be only using it for TV - ( what is an old Laptop for the time been 3.2 amp ) lights 2 x 8 watt - phone and tablet 2x .5 amp - using this say for 4 hrs a day ?? and maybe later on a new waterpump in de Van

so the usage is not much about 400 watts a day what is around 35 amphr if I'm right

beside the solar panel ( s) and the battery what else do I need, I'm realy lost on this point

no anderson plug to my car yet , dont know if I need it .would like to keep the cost down du to circumstances.

can some one tell me what parts I need to complete this and maybe were to get the parts

Thank you allready for the trouble of reading this

regards John

Cruising Cruze · Guru

G'day Greg
thank you for your reply
was thinking of getting this one
http://www.solarenergyproducts.com.au/ecommerce/12v-diy-solar-installation-kit/caravan-diy-solar-kit-160w-complete-kit-caravan-motorhome-boats.php
looks that it has an controller on it
Regards John

justcruisin01 · Guru

gst wrote:
Hi
You need a solar controler 20 can amp can pick cheap on ebay and a 100 amp hrs deep cell or 120 amp hr battery
and at lest a 85 amp solar panel or 120amp. the higher the better. If you to jay car they should be able to help you.

-- Edited by gst on Tuesday 2nd of October 2012 10:02:02 AM

-- Edited by gst on Tuesday 2nd of October 2012 10:04:24 AM

I think your 85 &120 amp panels should have read watts.

If your quote of 35 amps per day is correct then you need to be able to produce approx 1.5 times that to recharge your battery.

A 120 watt panell at full performance will give 8amps per/hr. At 6hrs of full charge is 48amps.

35x1.5= 52amps. replacement required .(approxamate)

In other words a 120 watt panel will be struggling to keep up when you consider a little adverse weather, even a few clouds throughout the day.

JC.

Cruising Cruze · Guru

thank you James it all becomes slowly a bit clearer to me :))

Loki · Senior Member

Hi John,
My calculation on your usage is about 80 AmpHours per day if you use all devices for 4 hours/day. You could cut that way back by using LED lighting, as your lights are the biggest drain. Your requirements are similar to mine and I have quite happily got by with two 105AH AGM deep cycle batteries, Morningstar regulator and a 100W portable solar panel. I use only LED lights when not on mains power, but I have a fridge that draws 2-3 amps. One other device you could consider is a DC to DC charger: You can get one that will charge your deep cycle batteries at the higher voltage they require, as the voltage direct from the alternator often is less than than the 14+ V they require to fully charge. This device will also isolate your starter battery when it gets below a certain voltage, so that your starter battery doesn't get drained if you draw too much in the house area. Also, to get the maximum life out of deep cycle batteries you shouldn't let them discharge below half capacity.
Hope this helps,
Anton

Cruising Cruze · Guru

Hi Anton

thanks for your reply mate I heard people talking about the DC to DC charger don't know btw how it works ( will look it up )
is the solar alone not good enough to charge the Battery ????
all I want is the Van being self efficient and don't want to spend an fortune with hooking the power of the car also to it just that we can go free camping a bit
we don't want to go for months at the time just 2 weeks at the time maybe ,and later on we see again
here in town they want 500 dollars to hook up an andersen plug with an Dual Battery Isolators boy o boy nearly 325dollars labour and that's why I want to run the Van on its own
that way we have no problems with the car at all ( I hope doing the right thing )

Regards John

justcruisin01 · Guru

Its a matter of working out your power usage & then the amout of solar as I quoted to fully recharge your batteries.

As for the anderson plug from the car, this system is much misunderstood by many, the bottom line is that you will never fully recharge a battery this way, you may get a small amount of charge & thats all.

If you want to be able to recharge from a car to a van the only way is to use a DC_DC charger, & that not much dearer than the anderson that you quoted which is a rip off price anyway.

JC.

PeterD · Guru

John regarding the DC supply from the alternator, you were a little short on details What size cable are they providing. Cable is not cheap, if they are using http://www.jaycar.com.au/productView.asp?ID=WH3070&form=CAT2&SUBCATID=995#1 the cable could be as much as the isolator. They could be using as much as 10 meters each of red and black.

A DC/DC battery charge (also known as a battery booster) is an inverter and multi stage charger in the one box. You could use an inverter powered from the alternator driving a standard charger. However you are making two voltage conversions with the resultant two power losses. If you use a booster you only suffer power loss from one conversion. As the process can be be made more efficient than each or the two desperate conversions you suffer less than half the loss. You will need heavy cable from your alternator but you could be able to get away with 6 gauge.

As far a being self sufficient for only two weeks, self sufficiency for more than 3 - 5 days will amount for the same equipment no matter how long you go. For backup I would recommend that you install a good multi stage battery charger of 10 - 15 A rating. If you do get into power starvation due to too long a period of inclement weather you just head for a caravan park for a day or three. That will be much cheaper than owning a generator. (You should have the mains driven charger fitted anyway.)

The kit you gave the link to should satisfy your needs. Some may consider the panel a little large but that is not really a problem.

Cruising Cruze · Guru

Thanks Peter and James for the reply

going today to the people of Jaycar here in town
and we will see what that is going to bring us

It seems to be all so simple until you start playing with it

thanks again all for your cooperation and your
thoughts

I will let you all know how we did today

Regards John

Cruising Cruze · Guru

well went and got my solar setup
going by the bloke at Jaycar need only 40 watt panel ( dont think so )
new Led lights .5 of a amp
Tv 30 watt - 4 hrs 10 amp
phone les than .5 amp 1 hrs
asus tablet the same
also e reader .5 for one hrs

that makes total 16 amp hrs a day so 80watt panel should be plenty

got it home including new AGM DEEP CYCLE 12V 100AH BATTERY hook every thing up and the mongrel charges at 17.7 volt
so back to the shop got the money back and went were I got the battery
same deal only on top of the panel extra 5 meters cable with plugs ( anderson )
a piece to conect with aligater clips and a piece with the right eyes so we can connect direct to battery also them 2 have anderson plugs on it
just set the whole thing up in the front of the house so the battery get charged all seem to be ok
charges with 13.8 till 14.4 volt this one
so I'm tickle pink now

also got small battery for the shower and a shower set, 12 volt 9 ah/20 hrs that works like a champ just try it
well this should do it all for us two and if not we have to go bigger
money is scares on the moment at least no big bills this way for the car and we hope we can charge the battery with the Sun
we going to try it out this weekend in Rossmore park ( the new name Kilkivan Bush Camping Park )
maybe we seen some of you

doei John