Before finalising the purchase of a vehicle, you think about the price, the options, and the crucial factor of fuel efficiency. Very often, you have to find a compromise between engine performance and economy at the pump.
Buying a laptop is a very similar situation. You need to take into account the price, the technical specifications and the wireless performance. Be prepared to make sacrifices on certain features.
Think of the laptop battery as the fuel tank. The power and features of the computer are the engine that draws on this electrical source.
It’s logical that the more powerful a laptop is, the more energy it consumes. As a result, the rule is simple: the more high-end your hardware configuration, the more you’ll be forced to stay close to a mains socket. This applies to standard six-cell batteries.
Why in-store battery life estimates are confusing
The best-selling laptops generally fall in the £400 to £600 price range. These machines offer moderate performance and most often have a 15.4-inch screen.
They usually come with six-cell batteries, with a capacity of around 50 to 60 Wh, or 4000 to 5000 mAh. When you ask sales staff about battery life, the answer is often very vague, ranging from “thirty minutes to three hours”.
This large variation in estimates is justified. It is directly linked to the hardware specifications and how intensively the laptop is being used. The biggest power-hungry components are the processor, the screen, the Wi‑Fi module, the hard drive and the optical disc drive.
It is therefore essential to be clear about what you will mainly use your machine for.
- If your main activity is writing and light web browsing, choose a laptop with modest technical specifications.
- A smaller screen size is also a real advantage.
- This approach helps you save money and reduce weight, while significantly extending the time between charges.
How to calculate your battery’s real endurance
So how can you work out the likely battery life of a laptop for yourself? Capacity is given in two different units of measurement.
- The first unit is the watt-hour (Wh).
Batteries in standard laptops have a capacity of around 56 Wh. The power draw of modern laptops is between 10 and 40 Wh per hour, depending on what they’re doing. Using these figures, you can estimate battery life and avoid being misled.
- The second unit is the ampere-hour (Ah) or milliampere-hour (mAh).
Standard batteries offer a capacity of around 4 Ah, or 4000 mAh. The average power draw of most laptops is around 2000 mA per hour. With a 4 Ah capacity, it is therefore reasonable to expect around two hours of use under an average workload.
However, some models are more energy-efficient. The 12.3-inch Toshiba Satellite, for example, uses around 1400 mAh. With a nine-cell 7500 mAh battery, its battery life can reach around four and a half hours under normal use.
