12 Volt panels produce more than 9 V
The previous reviewer must have missed something like a charge controller and may have a bad battery or a 9 Volt system. Good Panels produce 18 volts or more (always check the specs) and if you do not use a battery charger - or charge controller and are simply connecting the panels directly to the batteries you are wasting 50% of your power because (a) the voltage will never be higher than the battery pack. (b) the panel can actually over amp the battery causing battery failure, and (c) modern charge controllers have MPPT which helps optimize the array (if more than one panel is connected) and helps with less than ideal conditions or shade. Someone should call that guy in the Bahamas...
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