Most helpful positive review
123 of 125 people found the following review helpful
Works exactly as it is supposed to ...
on May 6, 2012
SOLAR PANEL: This panel is very well made, reliable, and seems quite weatherproof. It puts out the full 5 watts in bright sunlight. I put some silicone caulk where the wire exits the back of the panel, just to be safe.
EDIT: The charge controller failed after 19 months, and two replacements from Instapark were dead on arrival. The techie at Instapark said they are replacing that model of charge controller with a different model. So I can't recommend it any more. The solar panel is still good, but the charge controller didn't last long enough. So ... read all the information below with the failure in mind.
CHARGE CONTROLLER: The housing is definitely not weatherproof, but it does work properly. Some reviewers reported rusted connectors. Mine arrived without any rust. I created a battery box for an electric fence. The solar panel is mounted on top of the box, and the solar charge controller is inside the box with the battery and the fence energizer (protected from weather).
Don't use it with a large panel (as one reviewer did), because it's only designed to take a small current. It is rated for only 3 amps. 3 amps x 12 volts = 36 watts. So ... don't hook up more than 36 watts of 12-volt solar panels to this charger.
Another reviewer said the charger allows the battery to discharge into the solar panel at night. That's not really true. I did many tests and figured out what is going on. There is a green "Power" LED light on the charge controller. That light is on whenever it is connected to the battery. That light draws about 5 milli-amps from the battery at night, which is negligible. During the day, the solar panel powers the green LED.
So ... when the solar panel gets no power from the sun, electricity flows from the battery to the green LED. But that is the only draw on the battery. I tested it, and there is no current flowing into the solar panel from the battery. The 5 milli-amp draw is minimal, and really has no effect on the battery at all. Consider that during bright sunlight, the panel pours about 400+ milli-amps into the battery. Even that amount is just considered a "trickle" charge.
I put a blocking diode (1N4001) between the battery and the charge controller, which even blocks the 5 milli-amp discharge at night. Now the green "Power" light only comes on when the panel gets light.
I also verified that the charge controller stops charging the batter when it reaches about 13 volts. That protects the battery from being over-charged.
Hope this helps.