Harbor Freight panels
are chinese clones. They are fragile and won't last as long as the good ones. 5 watts is not much energy. That will keep your battery charged if it is full or close to it to start with, but to charge a battery that is low, it will take forever. Most people don't realise how much power they actually use. You need to quantify your power requirements and design around that. Example: assuming a 100 A/H battery that is discharged 50%, It will need about 65 A/H of current to charge them fully. A 100 watt panel will produce about 5.5 amps of current in direct sunlight. That will take about 12 hours, or 2 days to fully charge the battery. This is assuming that the panels are close to perpendicular to the sun the whole time. Factor in the real world conditions of cloudy periods and not being perpendicular it works out to more like 4 days to accumulate 65 A/H of current. A 5 watt panel would take 20 times as long. I don't want to discourage you, I use solar exclusively to power my house and it works very well, but it is a large inital cost. Google solar panels and start poking around the solar power and alternative energy sites to learn more about addressing your needs with solar. There is also alot about this in the archives.
