How to buy cheap solar panels on-line

Buying cheap solar panels.

Most of us like a bargain so buying cheap solar panels from an unknown source can be appealing. There is a glut of cheap solar panels available out there and it’s tempting to dive in and go for the bargain. Why pay more than you have to?

However, there are are a number of things to look out for. Buying the wrong product can be frustrating, ultimately expensive, and in some cases pretty dangerous. Here are a few pointers:

1. Wattage.

There’s no point in buying a solar panel that is not large enough to charge your battery. If you have a boat, motorhome or caravan your battery will be of the 12 volt lead-acid type. These batteries include liquid, gel, vented, low maintenance and AGM types. All lead/acid batteries need a reasonable charge current to make any difference. We recommend a minimum solar panel size of 30 watts. This size should maintain a battery in the summer months. It will however provide very little extra power for your appliances, lights, laptops and so on. For that you need a solar panel of at least 100 watts. 100 watts has become the minimum standard on most motorhomes and on many boats.

cheap solar panels

A typical solar panel with 36 cells. Perfect for charging 12 volt batteries.

2. The number of cells.

The solar panel is made up of a number of individual cells. Each one of these cells contributes a little to the charging voltage of the panel. You have to make sure that the voltage is high enough to charge your battery. For small solar panels of 50 watts or less you can get away with 34 cells but above 50 watts you really do need 36 cells.

3. Mean power point voltage.

Check that the mean power point voltage is over 17 volts. Any less and you run the risk of reduced charge and possible no charge at all.

4. High voltage.

Make sure the open circuit voltage is well below 30 volts. There are some cheap panels out there being sold as suitable for 12 volt battery charging but are in fact ONLY suitable for building into the roofs of houses. The high voltage from these can be dangerous if used in a boat or vehicle. Stay well away from these panels. They are often very cheap and can create a lot of damage to you and your equipment.

5. Frame quality.

Make sure the frame of the solar panel is strong enough to withstand severe buffeting.  The roof of your motorhome or the deck of your boat can be a very tough environment. The cells within the panel are fragile and need the support of a strong frame.

motorhome or narrowboat solar panel kit

A strong frame will protect the solar panel cells when on top of your motorhome, or at sea on your boat.

6. General quality of cheap solar panels.

It’s hard to gauge quality from an advert especially when there is only a photo to look at or when the technical aspects look a bit complicated. For this reason buy your panels from a reputable supplier. Phone and talk to them, don’t be afraid to ask any questions and make sure you are totally happy with the products before parting with your money. Getting your money back from an unknown supplier can be very difficult.

7. Guarantee.

Look for guarantees. Most standard solar panels should carry a 5 year parts and materials guarantee and should also offer a power guarantee of at least 25 years. These guarantees are standard on good quality panels from reputable suppliers.

cheap solar panels

Low cost but good quality solar panel kit

8. Buy a solar panel kit.

It is very important that you use the correct electronic charge controller and the correct cables, with your solar panel. This will make a significant difference to the charge sent to your battery. For this reason we recommend that you use a solar panel kit. The kit should contain the correct controller and the correct cables. Examples of solar panel kits can be seen on our website. Please click here.

9. Other considerations.

Whatever solar panel system you buy you want it to last and to work continuously and efficiently without interruption for many years.

SunWorks has been building and supplying solar panel systems and components since 2002 and there are many of our systems still working well from that time. We only select panels that we would be happy to use ourselves and we have been designing and building top class electronic charge controllers for almost 20 years.

10. To learn more.

As with most things you get what you pay for. Buying very cheap solar panels will usually not save you money, and could be dangerous.

If you would like to know more, please contact us using the form below: