- BBC World News
A fairly common question about the use of laptops is how to extend battery life (or at least, how to avoid shortening it more than normal).
Although all batteries deteriorate over time, many users question whether the use we give them can influence – even slightly – their ability to retain energy and power our devices for longer.
If so, then how should we use the batteries?
That is, should we keep them charged 100% all the time or should we connect and disconnect them according to their energy level?
Several experts with whom BBC Mundo spoke recommended the best way to use batteries, which are mostly made of lithium (either lithium-ion or lithium-polymer).
“Battery technology gets better and better with each generation. 10 years ago, the efficiency of laptop batteries started to degrade after a couple of hundred charge cycles,” says Ashley Rolfe, Lenovo’s chief technology officer. Ireland and the United Kingdom, to BBC Mundo.
Now laptop batteries typically have a life span of three to five years, in which they can complete between 500 and 1,000 charge cycles.
“You want the battery to give you as much energy as possible per charge and to last between three to five years,” Kent Griffith, an energy technology researcher at Northwestern University, tells BBC World.
How to achieve that balance?
Leaving a laptop plugged in and 100% all the time “is absolutely safe and perfectly normal,” says Rolfe, from Lenovo, to BBC Mundo.
Laptops from Lenovo and other brands “use sensors and control logic to ensure that the battery does not overcharge or overheat,” he explains.
Nevertheless, “keeping a battery at 100% all the time will slightly reduce its life“.
His colleague Phil Jakes, Lenovo’s director of Strategic Technology and principal engineer, agrees: “With the higher energy density chemistry adopted in recent years, we have found that batteries degrade much faster if they are kept fully charged, especially at higher temperatures, “he tells BBC Mundo.
The reason is that “100% charge is the heaviest condition your battery can be in because that is when the voltage is highest,” explains Kent Griffith of Northwestern University.
The manufacturer HP thinks the same, as it tells BBC Mundo: “HP does not recommend leaving laptops connected to alternating current at all times.”
“Most of today’s batteries have the technology to prevent overcharging once they reach 100%”, but this technology does not prevent the high state of charge “from creating additional stress on the battery that can accelerate its degradation over time. “explains HP.
So “if you keep the battery away from 100%, the battery can definitely last longer,” says Griffith.
The recommendation of these experts is limit the amount of time the laptop stays fully charged or instead of charging it up to 100%, charge it only up to 80% each time you plug it in.
“Technically, batteries are more ‘happy’ at 50% charge, while being under voltage at 0% or 100%, so the technicians say it is best to keep them between 20 and 80%,” says Rolfe.
While limiting the load to 80% “provides the maximum benefit, there is still a significant benefit to reducing the maximum load point to 90 or 95%,” says Jakes.
Microsoft also warns on its website that in the case of its Surface laptops (not for other brands) “batteries kept with high charge will lose capacity more quickly.”
“You can help prevent this accelerated deterioration by not leaving your (Surface) laptop connected to power for long periods of time. If you need to keep the laptop plugged in continuously, we recommend using the battery charge limit mode,” says Microsoft.
Several brands, such as Microsoft, Lenovo, and HP offer the option of limiting the maximum amount of laptop load in their configurations.
For example, HP allows you to limit it to 80% in “Maximize my battery health” mode.
In general, “if you want the battery to last longer, you could make each cycle give you a little less power (80% instead of 100%), but then the battery could complete more charge cycles,” says Griffith.
That is to say, it is about making “a balance between how long the battery gives you each time you charge it versus how many cycles it can complete” throughout its life, it continues.
How are you going to use the laptop?
But these recommendations do not necessarily mean that you should rush to disconnect the laptop immediately every time it reaches 100%.
“All laptops have control circuitry to protect the batteries and prevent overcharging. But you can increase battery life by leaving them at 80%,” says Lenovo’s Rolfe.
But at the same time, he clarifies that “batteries last so long these days that probably for most users it is not worth worrying about.”
Today “batteries are so good that they generally last longer than the life of the laptop,” he says.
Rolfe’s final recommendation is to think about how you will use the laptop. That is, evaluate if you are going to have constant access to a plug or if you are not going to be able to connect to the power for a long time. In the latter case, it would be better to take it with the full charge.
“If you’re at your desk most of the time, put a load limit,” he says. “But if you’re on the go most of the time, leave it at 100% and don’t worry about it!”
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Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.