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Review of Caravans Plus Service
Super fast delivery even in covid times. Always recommended. Thankyou
This article is the second in a series, if you have not read "Calculating how big your battery needs to be." I suggest you read it first, as it explains a lot about batteries and how they should be set up. There is already a lot of information out there, but our articles are directly related to RV's and the Australian situation. The article will expain how to get more from your batteries by either supplimenting the charging with solar or going for a complete solar system.
Not everyone who reads this needs a full system, I will cover the basics first.
Above: Glass Solar panels have been around the longest and offer the best solution in household and commercial installations.
Above: For mobile applications the semi-flexible panels offer some advantages, but generally at a more expensive price.
Above: Folding panels in both glass and flexible are very popular with Campers due mainly to the ability to move them around to catch the most sunlight.
A solar panel is a grouping together of individual solar cells to produce an electric current. The electric current leaves the solar panel and goes through a solar regulator then into a battery. While you can run a 12V appliance or light directly from some solar regulators, a more basic setup connects everything to the battery.
Above: A single panel generates around 17 to 19 volts. The solar regulator then reduces that voltage to a suitable charging voltage for your battery.
Multiple panels and batteries can be connected to a single regulator but that will be discussed later.
A solar panel is made from solar cells. Different solar cells can produce a different number of watts from a given surface area. This is particularly important for the limited mounting surfaces available on a Caravan or Motorhome.
As detailed above, the cells can be bonded to glass or a semi-flexible base. The temperature of the panel surface can effect the output also. This is a reason given to support the use of raised glass panels. While I have not tested the difference in output in identical circumstances, I chose a flexible panel due to the weight reduction, durability, and ease of cleaning. The cost was only marginally more after the price of mounting brackets was added to the glass panel cost.
Fixed panels are extremely convenient and more secure from theft compared to portable panels. Portable panels allow for maximising solar capture by locating and pointing the panels directly at the sun. Theft of portable panels can be an issue particularly if leaving the campsite unattended. You also need to allow storage space for portable panels that are packed up and not operating during travel.
A panel that can be fitted to a roof during travel and only removed when setting up in a shaded position is also a real option.
The specifications of a solar panel will indicate the output voltage and output wattage. Solar panels can be joined together to give additional wattage output at the same voltage.
Remembering from above, a solar regulator controls the voltage that comes from the solar panel to what the battery needs to charge correctly.
The solar regulator will have a specification for the maximum number of amps it can accept from the solar panel(s). Adding the total number of amps from multiple connected panels will give the minimum sized regulator you need. Don't skimp on this, as many people decide to increase panel numbers or size after a while. Another reason not to cut it too fine is that solar panels can actually exceed the quoted output in ideal conditions, especially in full sunshine but cold ambient temperature.
Another important consideration is if the solar regulator can vary the output to maximise the battery charging like a multi-staged battery charger. This allows faster battery charging at the beginning and float charging to get the battery up to 100%.
Some other features that a solar regulator may have are:
Some solar panels come with MC4 connectors which allow for easy waterproof wiring. We also sell the easy to add connectors. There are adapters available that permit joining two cables to one. An easy way to add any number of panels to the one set of wires. These provide a perfect junction for testing if a fault occurs.
Many people install solar panels by cutting the connectors off and soldering, but troubleshooting problems is easier with the connectors in place.
The instructions that come with the solar regulator will identify the wire thickness required depending on your distances, but RV applications normally use 6mm square UV stabillised wire connecting your solar panels to a solar regulator. The same thickness wire can connect the regulator to the first battery. When connecting batteries together you are advised to use premade battery leads available through automotive parts suppliers. If you have a large inverter, say 2000w, you would also connect it with battery leads to the battery bank.
Many people love their first solar panel and the free power they get, so they decide to upgrade. It is an easy upgrade if you have the space.
Above: 2 panels (or more) can be connected in parallel (positive to positive) resulting in the same Voltage, but double the Watts. Also 2 or more batteries can be connected together in parallel to double the storage capacity. Having 2 or more batteries allows larger inverters to provide 240V for equipment like microwaves.
An example installation may have 4 x 100 watt panels, that produce (4 x 5.5) 22 amps. This is within the capability of a 30amp regulator and will give a healthy charge to your battery bank.
Above: This diagram represents a more comprehensive 12volt/240V system that is very functional and would meet the requirements of most Caravans and Motorhomes.
a) A battery charger will be used to charge your battery(s) when 240volts are available.
b) A multi-stage charger is best, plus the higher the Amperage output of the charger, the faster it will recharge.
c) When the sun shines, the solar panels will feed a current to the solar regulator.
d) The solar regulator will first try and supply current to any 12volt devices (f) connected directly to it.
e) Any excess current from the solar panels will go to the batteries to recharge them. The batteries can accept charge from a battery charger and a solar regulator at the same time.
f) While 12volt lights and devices could be connected directly to the batteries, the better solar regulators will prevent over-discharge of your batteries if you connect the devices to the 12volt load terminals provided on the regulator.
g) Most installations will now include an inverter, which generally gets connected directly to the batteries. The inverter produces 240V that you can connect any **240v appliance to.
**Warning: Do not connect your battery charger to this 240v outlet. Specialised switching is required to input the 240v back into your 240v circuit.
For more information on how many panels and how many batteries you need, see "Calculating how big your battery needs to be."
Super fast delivery even in covid times. Always recommended. Thankyou
Caravans Plus is a fantastic place to find heaps of very good items for your caravan. They also let you know if items are in stock or not. Some other sites you can put an order in for items only to find that they are out of stock & you have to wait until they come back in again before your order is sent. I started out with just one order, however I have now made 3 or 4 orders. Everything in all of the orders I made was received very quickly as well. They are also very helpful with advice if you have any questions. I would definitely recommend Caravans Plus to everyone. On a rating out of 10, my rating would be 20. C U L8R. Phil
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