Solar panel battery chargers can be a great way to keep all of your portable electronic devices charged no matter where you go. There are different products available, some that charge the device directly from the panel, others that have an internal battery, which needs to be charged, then discharges to the linking device. There are many good qualities about solar panel battery charges, but there are also some things that you should know about them before you run out and buy just any product.
For smaller electronic devices, solar panel battery charges should have an internal battery, which charges and then is hooked to the device. This is because solar power isn't continuous, and has fluctuations, depending on the sunlight available. If you get a spike, and it is directly connected to your cell phone, it might fry the battery in the phone. Many larger solar panel battery chargers for car and RV's have a built in surge protector.
The advantages of using a charger with a built in battery is that you can buy a smaller sized panel, with will save you money. The disadvantage with these is that the internal battery doesn't have a very long life, just a few years or so. The other disadvantage is that because the solar panel is small, it takes longer to charge the internal battery.
Now there are also advantages and disadvantages of using a larger wattage solar panel battery charger. Usually these panels are available in sizes of 5 watts or more, and a generally good wattage rating is 15-20. Now while these larger sizes can charge up a laptop in a short period of time, there are some things you need to think about. One is that you may need a regulator in order to prevent spiking.
When you are considering buying a solar panel battery charger to charge up you RV or car battery, there are some important considerations. There are many solar chargers available that are in the 5 watt range, but these are slow, trickle charging systems, which produce less than an amp per hour of power. Even a 15 watt panel only produces about one amp per hour.
This generates a problem when you are thinking about using a smaller panel for keeping your larger batteries charged. You have to think about this. In both a car, as well as a recreational vehicle, there are two types of electrical draws, passive, and active. When you are using your radio, CD player, pump for water, or lights, this is an active power source, which draws a lot of energy.
Even when you think you aren't using anything in your vehicle or RV, you actually are, hence the passive power source. In cars, there is still power being used to keep the clock active in your radio, and some electronics draw power even when not in use. This holds true for your RV, especially in newer models. There are internal monitors, small indicator lights, as well as electronics in your RV refrigerator that are constantly drawing power.
What this means is that even if you buy a 15 watt solar panel charger that produces one amp per hour, you are using part of that already. In order to prevent your battery from draining using solar power, you need at least a 20 watt or more panel. Most people use at least a 25 watt panel, just to keep there battery charged. The more batteries, or voltage your system requires, the higher wattage you are going to need.