Just installed today, the instructions for the controller aren't very good but I found some great videos on YouTube on how to program the controller. I hooked it up to my caravan's deep cycle battery and on a cloudy day I still get 12.9 volts from the south facing solar panel. I wasn't sure what to expect from that $33 but it does the job perfectly and I can always upgrade to a larger solar panel with this controller. I highly recommend this device. I have looked at several tenders for solar panels and this is by far the best offer. The most important thing is to program the controller correctly. The solar panel has not been exposed to rain, but I install the controller in the battery box. If you search the controller on YouTube you will find some helpful videos to help you program. For $33 I really like this unit, no more dead battery in my RV. I bought it because I just bought a new deep cycle battery and they aren't cheap. Very satisfied, I would buy again.
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