I'm trying to find out how much electricity something consumes while charging for 7 hours per week. My Gameboy says Input: 5.2V --- 450mA. I tried to get the watts by multiplying 5.2V by .45 and got 2.34W. Next I multiplied by 1, for one hour then divided it by 1000. I got the kWh? And after that I multiplied it by 7 to get how much it is charged per week. Is this how? Also, if you know how to calculate correctly, great, but if you know a site which already gives this info, please tell me it. Regards. Thanks.