Electricity usage (and costs) of common household appliances


Expert Member
Apr 19, 2007
This depends whether you charger is all the time powering your laptop. It varies from 1 Ampere to 3 Ampere /18 Volt. with an efficiency of 84% gives you an average of (1,5 x 18 )/0.84 x 24 hours = 772 watts per day = per month 23 kwh or units. We pay R1.60 per kwh and that means R36,- having it on all the time. I normally remove the charger after use, which saves me about 20 Rand per laptop ( I have 3 running). Trust that this helps you. I like to live in the area which charges 40.1 cents/kwh instead of 1,60. I think the calculations are some 20 years old with 40.1 cents /kwh Bert
Wow, 10 years later...