Solar Panels

[threedogs]

Remember you can go too big in wire size, what you intend using sounds fine,
Anderson plugs worth their weight in gold love them
You wouldnt use welding cable to run an indicator would you, or would you.

[oncedisturbed]

will confirm the size when it comes in as it may be the 50A is to big and may have to drop slightly

[threedogs]

Other than powering a winch I think 6mm cable is heaps for most H/D automotive jobs
Amps and Hi tech radio equipement excluded doof doof

[Woof]

I need one just to keep my 60 litre Engel fridge/freezer running, so my question is would this one do it without any changes..........I know nothing about solary/eletricy stuff

[Cuppa]

Re.the discussion on cable size for solar

To make sense we need to refer to the mm2 of copper in the cable rather than the amps it can carry, as the size of cable to amp carrying capacity ratio varies with voltage.

6mm autocable may be sufficient for most things automotive, but often only has about 4.5mm2 copper (the thickness of the insulation being included in the measurement of autocable). 6mm autocable is insufficient for most but the smallest solar installations.

6mm2 cable would be be the minimum for a single 100w panel & 10m of cable.

You can't go too big in cable sizing from a solar point of view but of course the compromise needed is to avoid excessive weight. Also the bigger you go the more the returns diminish. There are plenty of web sites which will tell you what size cable you need for a given voltage drop. Aiming for a max voltage drop of 3% is reasonable for solar installations. For 300w of portable solar & 9 metres of extension cable I use 6 b& s cable which has 13.3mm2 of copper, which is getting close to light welding cable. To go to say 12 metres I would use 16mm2 which is light welding cable!

The following link has a good table for determing solar cable sizes
http://hobohome.com/news/?p=581

Cuppa

[Cuppa]

Another link.
http://stores.ebay.com.au/Low-Energy...opments?_rdc=1
This mob come very well recommended within the Motorhome & Caravan community.

Cuppa

[3kids]

Hi all,
I am presently setting up a camper trailer and as luck would have it I am an electrician (heavy industrial). After a heap of private research I have just put a rev 1 system together.
Firstly let me state that all prices I got from an auto spark literally tripled the cost of what I believe you need (lots of smoke and mirrors).
A 50 amp anderson plug can only just accomodate 6 B&S (13.5mm2) cable with some strands not being able to fit in the lug. 8 B&S (6mm2) fits comfortably.
As stated all cable lengths need to be below 10 metres due to voltage drop (when starting from a low base like 12 volts VD becomes a show stopper for recharging) and cable size is minimum 6mm2
The MPPT charger that is supplied with a quality solar panel is OK (but) they usually do not come with a cut out to prevent overcharging and can damage/reduce battery effectiveness. To really extract the most out of a system and keep it simple is to have a DC-DC charger that can simultaneously charge with the alternator and solar or individually. These units provide optimum charge rates (incoming voltages of say 11.5 volts are converted to 14.6 volts) and cut out to prevent over charging. You can also connect and leave connected a 240 volt charger eliminating change over of leads when you park up after the trip or hit the powered site. Ensure the charge unit or regulator is paced as close as is possible to the batteries.
Please feel free to ask questions as I am in the process of building this and so far the results have been above expectations. > 6 days and nights with 2 x 100w solar panels and the batteries never dropped below 80% running LED's and engel, by the time we returned to Perth the batteries were back to 100% via the alternator.

[Cuppa]

Which Dc to Dc charger have you fitted Dave? The Redarc BCDC1240 I have handles solar or alternator, but not both at the same time. Precedence is automatically given to the alternator. I too am similarly impressed with how well these things work.

Cuppa

[3kids]

Hi Cuppa,
At present I am experimenting with the CTek DC-DC charger with a Smartpass unit parralled with it (sampling them from 1 of our contractors on site). The unit is mounted nearly on top of the batteries being charged. Alternator feed is via a 50 Amp anderson plug wired with 6B&S cable (13.5mm2). Yes some of the flexible copper strands are not captured by the lug but I took great care to ensure no short circuits. Voltage at the rear of the tow vehicle (not a patrol) is 15.5 volts. Due to trade access I have used 6mm2 twin as a minimum for any back bone cabling with 2.5mm2 cable breaking out in short runs to LED's which aren't affected too much by VD. All joints and terminals are crimped or soldered and the main form of connectors are anderson plugs for the trailer to tug and power poles for all else (these just accommodate 6mm2 cable). The power poles are brilliant for slightly smaller cable sizes and can be used over and over without compromising the quality of the joint or being too bulky.
1 point I am researching is that new alternators (2010/2011 onwards for all makes and models) are not capable of delivering a voltage of consistency to work like this due to electronics. I will be searching for a solution (and or confirm this is the case) to this as my new toy as of tomorrow is a 2012 Patrol (cant wait).
The two panels are cheapies but after using a tong clamp I am reading 7.9 amps in the morning prior to driving off for the first time. At camp I was only recieving full sun from 10 AM onwards. The main thing to have for me is the cut out for protection of the batteries and if using a regulator/controller it is of the MPPT variety C/w cut out. All the regulators/controllers I have viewed to date dont seem robust enough and I have my doubts.
The other advantage of the CTek was being able to leave the 240V charger permanently connected without worry of discharge. The manuals wiring diagrams are simply put together.
I must repeat the bit about modern alternators, the expense of a new Ctek arrangement is steep (I reckon) and I want to ensure it will be compatible in the future. Talking to a technician the company is currently working on it.
Will take photos over the Easter break

[Cuppa]

As I understand it many newer vehicles have alternators which put out voltages too low to effectively charge 'house' batteries, restricting the charge voltage to a little over 13v, enough to replenish the crank battery ready for the next start only. I believe this is to help reduce fuel consumption & that dc to dc chargers are a good solution on these vehicles to charge 'house' batteries. However I would be surprised if a vehicle like a Patrol, commonly fitted with a dual battery system, would have such a 'restricted' alternator ...... but you never know. Let us know when you get a chance.

Cuppa