Electricity usage.

[Tilly2]

How much is it costing me to have this laptop on for most of the day?
Would it be better to use the battery and then let it charge up or does the charging up bit use more electricity?

[ChuckFickens]

I'm afraid I cant see that laptop so it's a little hard to give a precise answer.

Laptops on the mains use between about 15 - 75 watts depending on a lot of factors such as screen size, processor, load, screen brightness and so on.

if it's a really high power laptop (75 watts) and assuming your electricity cost 15p a unit (which is pretty high) it would cost 27p to run for 24 hours

If it's a really low power laptop (15watts) and with the same electricity costs it would cost about 6p for 24 hours.

The difference between running on mains all the time and running on batteries and then charging is going to be so tiny it's not worth worrying about.

[Tilly2]

Thank you, chuck. The reason i didn't put model number and make is because it's a generic laptop from the local computer shop and doesn't have a name.
The only thing I can find on the label at the back, along with references to Canada, is 19v-3.42A

[ChuckFickens]

That makes it a 65Watt power supply.

the rating of the power supply will be a little above what the computer will draw as it's maximum so you'd probably be looking at about 30-50 watts depending on exactly what and how the laptop is being used, so it would cost you between 11p and 18p to run for 24hrs (again assuming 15p per Kwh cost of electricity, which is probably a little higher than you are paying.)

[Tilly2]

What a splendid answer. Thank you.