Hi all, Just wondering if someone with more knowlege than I have, can advise me on wire size for solar panels. Our van has one 130 watt panel, a 30 amp charge regulator and 2 x 100 amp hour batteries. The wires connecting the solar panels to the regulator have a core diameter of 3mm (just the copper not the insulation ) and a length of about 5 or 6 meters. I would like to add another panel on the roof and use the same wiring, as it is a fairly new van and I do not want to have to lift the cladding to upgrade the wiring or run more. Can any one suggest how many watts this original wiring can take.
Cheers Landy
Hi Landy
The cable is capable of carrying around 40A without overheating
So no problem as far as current is concerned
Voltage drop will be around 0.03V per amp[with that length]
Two 130 W panels will put out around 15A
Make sure the panels are rated at the same voltage.
So voltage drop will be round 0.46V
Getting near the limit, but as long as the REGULATOR is reasonably close to the battery, no problem.
What is the distance [run length] from reg to battery???
Simply join positive to positive & negitive to negitive AT THE PANELS!!
What type of regulatorPWM or MPPT???
PeterQ
-- Edited by oldtrack123 on Saturday 30th of March 2013 12:19:05 AM
-- Edited by oldtrack123 on Saturday 30th of March 2013 12:19:44 AM
Hi all, Just wondering if someone with more knowlege than I have, can advise me on wire size for solar panels. Our van has one 130 watt panel, a 30 amp charge regulator and 2 x 100 amp hour batteries. The wires connecting the solar panels to the regulator have a core diameter of 3mm (just the copper not the insulation ) and a length of about 5 or 6 meters. I would like to add another panel on the roof and use the same wiring, as it is a fairly new van and I do not want to have to lift the cladding to upgrade the wiring or run more. Can any one suggest how many watts this original wiring can take.
Cheers Landy
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In life it is important to know when to stop arguing with people
and simply let them be wrong.
I used the cable from Jaycar, about $4 a metre, from memory the copper was 3 or 4mm, so i think what you have would be OK. have 2x 80watt panels and a 30amp Controller. If in doubt I would call Springers in Brisbane.
I paralleled up the Solar and the batteries in such a way that the load was shared eg for the batteries, the negative of one battery went to the controller and the positive of the other went to the controller, then they were parallel up. Similar for the Solar Panels.
landy wrote: Can I tell by measuring the voltage into the regulator when the sun is shining?
There is a couple of ways you can tell if the panel is a nominal 12 V one. Firstly if you can reliably count the cells a 12 V one will have 36 cells. The other way is to disconnect the panel from the regulator from the regulator and measure the open circuit voltage in good sunlight. The voltage will read around 21 V.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
@Landy: mate, all good info provided thus far for sure; great input from informed folk etc
so.....if I may add (apologies if this is a moot point BTW), make sure that the wiring and infrastructure is connected and protected securely(i.e. suitable/robust enough for the environment you are travelling through and to).
That way, you will have no 'surprises' regarding weather/terrain issues versus power supply expectations.
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A good traveller has no fixed plans and is not intent on arriving. ~ Lao Tzu
