What happens when the battery is fully charged but still connected? The question here depends on the type of battery being discussed. Since most devices now have Lithium-ion and Lithium-polymer batteries, we will take that into consideration. That said, let us take a step back. Any battery if overcharged will heat up or blow up or lose capacity. However, technology has advanced enough that it can be avoided. In this post, I will discuss what happens when the battery is fully charged but remains connected. It applies to laptops, mobile phones, and rechargeable batteries.
What happens when the battery is fully charged but still connected?
Many of us keep our phones and laptops plugged in and charging overnight. It ensures that it’s ready for prime time when you wake up. However, many feel worried if it will blow up or overheat as a full charge usually takes 2-3 hours tops. Here is the deal. OEMs have ensured that those batteries are not overcharged, even when stored for long periods.
Protection Circuit
Most phones, laptops, and other devices today utilize smart chargers that automatically detect when the battery is fully charged. Once the battery is fully charged, the charger tapers off the current or switches to a Trickle Charge mode.
Technically, these days batteries don’t overcharge, thanks to OEM’s implementation of internal protection feature. As soon as the battery hits 100% mark, the internal circuit disconnects the power source from sending any other current. The power circuit is designed to detect the upper limit and will disconnect the power when it reaches the limit.
As soon as the battery is fully charged, it stops receiving charging energy. The circuit bypasses the current directly to the laptop’s power supply system. It breaks one of the laptop battery myths that the battery always powers laptops.
Rechargeable batteries
In the case of rechargeable batteries, it entirely depends on the OEM. While it works on the same principles, check with the OEM if they offer a circuit breaker when the charge is complete.
Most mobile phones and laptops come with this feature, but it’s still a good idea to check with your OEM.
I hope the post was able to answer what happens when the battery is fully charged but still connected and other questions around charging and battery.
Should you keep the laptop plugged in all the time?
There is no straightforward answer to this. Every OEM has its recommendation. Some OEMs are ok if you keep it on charge all the time, while some recommend you to discharge the battery from time to time. It keeps the battery functioning properly.
That said, here is another factor you need to consider. If you live in a place with high temperatures, it’s a good idea to unplug it from time to time and plug it in only when the battery percentage falls below a certain level. High temperatures usually reduce battery capacity.
TP: You can create a laptop battery full charge notification on Windows.
Is it better to remove Laptop battery when plugged in?
It’s not a good idea because if the power fails, you will lose your work. However, many follow this pattern thinking it will increase battery life as the use will be less. That said, internal heat is one of the significant factors which impacts battery life.
When using the laptop for casual work that doesn’t require heating, keep the battery in the laptop. If you are doing intense work that generates a lot of heat for a longer duration, it is best to take a break.
So it’s not just about the ambient temperature but also about the internal temperature. A lot of gaming laptops offer a cooling feature which increases fan speed and bent-out heat or lower CPU usage, etc. These cooling features can also be activated manually for certain laptops.
TIP: Take a look at these free Battery Limiter software for Windows.
How does over-discharging impact battery life?
Just like overcharging, over-discharging is terrible. If you do not charge the battery for an extended period, it loses its capacity. The battery develops internal resistance, and the chemicals start depositing. That causes problems.
