To put some figures on it, that solar panel generates 13.2 watts. Probably in ideal conditions, i.e. direct, strong sunlight. To run a coolbox drawing 5 amps you would need 60 watts, but even then that would be in ideal conditions. If I wanted to run a coolbox just from a solar panel, I would be looking for one that could give out at least 100 watts.
As they say in the advert, that solar panel is ideal for charging phones, and that's about all I would imagine.
USB is 5V, with 500mA maximum current output as the standard. There are charging "addenda" that allow up to 2A if the socket and device are capable. 5V at 2A is 10W.
It is possible to convert 5V up to 12V, but you're still limited by that power output. The conversion will only be about 80% efficient, so even if you could get a full 2A output from the USB (unlikely), you're looking at about 8W, or less than 0.7A at 12V.
So looking at it another way. Could the cigarette socket power leads to charge up a spare leisure battery as we drive? This way I would have a spare battery to power the fridge when stationery
Not an ideal way to do it, but I'm sure it would work. However, bear in mind that the continuous drain of a coolbox will flatten quite a large battery in a matter of hours, which is why most caravan fridges run on gas or mains EHU when on site.
Another thing to bear in mind is that the wiring to a cigarette lighter socket in a car is probably not capable of handling the large current required to charge a large, flat battery. If you want to go down that route it would be a better idea to have a proper split-charging system wired in to your vehicle. Its quite easy to do.
Yes, Fleck2, I quite agree. I once had a coolbox on my boat, and it completely flattened my leisure battery in less than a day, whereas on the next boat I bought I fitted a compressor fridge. On one occasion I forgot to turn it off when I went home and the following weekend it was still running.
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Topic: Usb ports to a 12v socket possible?? Help
