10 amps is the maximum this charge controller will pass on the OUTPUT side. That will be at battery voltage. The amps you are referring to is the amps on the input side which will be at a different voltage. The recommended max panel wattage for this controller in a 12 volt battery system is 145 Watts and if you do the Watts = Volts x Amps math you will see that is based on the battery being at 14.5 volts