If you’ve ever kept an old laptop or phone in a drawer for months and when you turned it on again you noticed that the battery didn’t last as long, it’s no coincidence. Lithium batteries have a very explicit way of working and, when we don’t treat them well, they let us know. Today we explain how charging cycles work and why leaving your device without battery for a long time can be an expensive mistake.
What exactly is a charge cycle?
A charging cycle is not just “once you plug in the device.” A complete cycle is equivalent to consuming 100% of the battery capacityregardless of whether you do it all at once or in parts. For example, if you use 50% of your laptop today and another 50% tomorrow, you’ve technically completed an entire cycle.
Now, how many cycles can a battery last? Lithium-ion batteries in modern phones typically perform well between 500 and 1,000 cyclesafter which the capacity begins to fall gradually. Laptops, for their part, usually have a lower range: between 400 and 600 cycles before showing primary degradation. When you exceed that threshold, the device may arrive in the middle of the day with the battery already depleted, although before it lasted perfectly.
The important thing here is to understand that every cycle counts. It is not that the battery “breaks” from one day to the next, but that is progressively degrading with each loading and unloading. Therefore, the charging habits you have from day one make a huge difference in the long term.
What happens to the battery when you leave it discharged for a long time
Here comes the part that many people don’t know. Leaving a battery completely discharged for weeks or months is one of the worst treatments you can give it.. When the lithium battery remains at critical levels for a long time, unpleasant things begin to happen internally.
First, a degradation layer forms on the electrodes and the internal electrolyte breaks down. This generates a high internal resistancewhich causes the battery to stop charging well, or simply not charge at all. In lithium batteries specifically, the built-in protection system (called BMS) can lock out as a safety measure, rendering the device essentially unusable.
Besides, Completely discharging a battery can cause irreversible damage to the internal cells and decalibrate the sensors that measure how much charge remains. This results in incorrect readings: the phone can turn off at 20% because the system no longer knows exactly where the battery really is.
What if you keep the device but with a full battery? It’s not the ultimate either. The most recommended thing is to store a device that you are not going to use with between 40% and 60% chargeat room temperature, to minimize stress on the cells.
Habits that extend battery life
The good news is that taking care of your battery doesn’t require being an electronics expert. With a few simple changes you can significantly extend its lifespan:
- Keep the charge between 20% and 80% whenever you can. This range within the low cost of stress on the electrodes and avoids extreme voltage states.
- Avoid charging overnight on a regular basis. Although many modern devices have overcharge protections, the heat generated for hours can degrade the battery over time.
- Never leave a device in storage with 0% battery. If you are going to store it for more than a week, make sure it has at least 50% charge.
- Use original or certified chargers. Poor quality generic chargers can alter the charging rate and damage the cells.
- Watch the temperature. Extreme heat accelerates chemical degradation of the battery, while cold can cause erroneous readings and unexpected shutdowns.
Many manufacturers already include smart charging modes in their devices. Samsung, Apple and Lenovo, for example, have options to limit the maximum charge to 80% precisely to preserve the battery in the long term. If your device has that feature, use it.
In short, lithium batteries are sophisticated but shiny technology. No deep discharges, no constant overloads, no prolonged abandonment These are good tips if you want your laptop or phone to continue working well in two or three years. Treating the battery right from the start is much cheaper than replacing it later.
Keep reading:
• Apple and Samsung will have to allow you to change your cell phone battery thanks to the new European Union law
• How to know exactly how many hours of battery life your phone has left
• At what percentage of battery health should you start worrying about your phone?
