You only have to need a power supply, and then you can use it all day long. You should use it on a table or something else to block the air coming out from the vents and let them circulate to keep the system fresh and perform better. You can also connect your laptop to AC power so you can use it for a whole day or maybe for two days. Our Acer Aspire 5 A515 is best for everyday use, and its battery works great for daily routine tasks, movies, Netflix, and youtube videos.