Laptop battery when using power cord (installed, work, remove, memory)
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If a laptop is plugged into the wall power, does the laptop use the battery absolutely zero? Or does it use the battery a small amount?
It depends on the make and model and the charging/power technology used.
In older models and some newer models, typically, the machine would still primarily use the battery and would also allow it to be charged if it was plugged into a wall outlet.
Newer machine might be using a trickle charge function, charge up to 99% +/- 0.5% and switch to using the battery until it drops to a certain level then kick it into charging mode.
Some models switch to AC power while monitoring the battery charge level. It really depends on the charging technology and battery used in the machine.
So, for most make and models, if the battery is installed whether AC power is connected or not, battery is in use as this serves as a redundancy for power and data loss while also shortening the battery's life ergo creating business for the company.
I am thinking that is one of the main reason why newer laptops come with an internal battery. Another is likely to be cost.
More and more newer model laptops are coming with no CMOS battery so the machine relies on the presence of the internal battery to keep its settings, time/date info in the BIOS.
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We have an older laptop and even if it's plugged into power, the battery charge decreases by small amounts. It could just mean it's old. And yes, it is really old.
Again, this also depends, on not so much the age but its overall condition/health, build quality and type (NiCad, NiMH, Li-Ion). NiCad is cheap and lighter than NiMH but requires more frequent recharging due to its lousy charge retention. NiMH is sturdier, heavier and holds charge longer but more expensive. Both types are prone to charge memory effect. The more expensive Li-Ion is not prone to this "memory effect" it also can hold the charge almost as good as NiMH but handles recharging much better hence much longer lifespan.
So, whether you want to keep the battery in all the time or remove it when using AC power will also very much depend on the battery type!
As rjm1cc mentioned, most any laptop I worked on requires battery to be present during BIOS update due to the off chance that AC power is gone, you do not want to end up with a dead laptop.
This topic has been covered in quite a few other threads but in a nutshell, hard to give definitive answers/suggestions due to all the abovementioned variables.
My ~10 yo Lenovo T440 came with an Li-Ion battery. I remove the battery when I am using AC which is 98% of the time. Pop the battery in couple of times a year to keep it charged.
That is it. Battery still has 100% health and holds 100% charge.
Important Note: You can use a charger with higher wattage than required but you can/should not ever use a charger that is underpowered! Example: laptop requires 65W charger and you plugged in a 45W charger.
This can damage any or all of the following components: DC check, motherboard, battery and the charger itself. It could even start a fire!
Last edited by TurcoLoco; 05-14-2023 at 03:58 PM..
Important Note: You can use a charger with higher wattage than required but you can/should not ever use a charger that is underpowered! Example: laptop requires 65W charger and you plugged in a 45W charger.
This can damage any or all of the following components: DC check, motherboard, battery and the charger itself. It could even start a fire!
This is not an issue for USB chargers. The laptop and charger will negotiate the safest wattage to use for charging and it won't damage any components.
This is also true of magsafe (Apple), Lenovo Slim Tip (yellow flat connector) and modern Dell chargers. I'd stick to a standard USB charger than a proprietary one, however.
That being said, if your laptop cannot draw enough power, it will throttle the CPU and/or GPU. And it will cut off charging the battery as the laptop draws higher power.
One other thing to note is that laptop chargers are designed to power the laptop at full load while charging the battery at the same time with some overhead. Most of the time, you aren't maxing out a charger.
This is not an issue for USB chargers. The laptop and charger will negotiate the safest wattage to use for charging and it won't damage any components.
Not sure what a "USB charger" is, I don't think I have seen or used one.
(AC) charger I was refer to plugs directly into a wall outlet to provide DC power to a Windows laptop.
Not sure what a "USB charger" is, I don't think I have seen or used one.
(AC) charger I was refer to plugs directly into a wall outlet to provide DC power to a Windows laptop.
A USB charger plugs into an AC outlet and into a laptop's standard USB port to charge the laptop. This is used by Apple, Dell, HP, Lenovo and several other brands. Many models still use legacy proprietary chargers as well.
A USB charger plugs into an AC outlet and into a laptop's standard USB port to charge the laptop. This is used by Apple, Dell, HP, Lenovo and several other brands. Many models still use legacy proprietary chargers as well.
I think you meant USB-C, not regular USB (2.0/3.0).
That is a very important distinction.
Only newer laptops have that port and not every USB-C port supports power delivery and charging.
It is very device and also port specific. If the device came with its own proprietary charger, it is not likely to allow charging using any other generic USB-C chargers regardless of the port used.
Even though USB-C based chargers are more universally interchangeable, it is not always the case.
I believe Apples are much more unified in that sense where certain Windows OEMs make proprietary USB-C chargers that do not allow users to use just any charger due to device's specific requirements.
Again, that server two purposes, it protects the device from getting damaged while also allowing OEM to sell their own proprietary chargers for additional revenue.
I think you meant USB-C, not regular USB (2.0/3.0).
That is a very important distinction.
Only newer laptops have that port and not every USB-C port supports power delivery and charging.
It is very device and also port specific. If the device came with its own proprietary charger, it is not likely to allow charging using any other generic USB-C chargers regardless of the port used.
Even though USB-C based chargers are more universally interchangeable, it is not always the case.
I believe Apples are much more unified in that sense where certain Windows OEMs make proprietary USB-C chargers that do not allow users to use just any charger due to device's specific requirements.
Again, that server two purposes, it protects the device from getting damaged while also allowing OEM to sell their own proprietary chargers for additional revenue.
"Standard USB" (the term TL used) and USB-C are the same. I think you're referring to "Legacy USB" when you reference 2.0/3.0 (also, I think you mean USB A/B here).
Newer is relative. HP, Lenovo, and Apple made the transition 9-10 years ago. I have a 9 year old HP Spectre that uses USB charging. Also, in many cases, on laptops of these brands, all the USB ports (except legacy ports) supported charging.
Also, newer Apple Macbook Pros come with proprietary magsafe 3 chargers and still support USB charging. As does many Thinkpads including the T470, T570, X270, 370 Yoga (all of which were ~2018 era).
One thing about USB PD is that it's backwards compatible and you can use older lower wattage chargers to charge your laptop without causing harm. Legacy USB chargers have circuitry to shut off if to high of a load is requested as many of them (USB 1.0) don't negotiate amps. But USB spec itself starts at 500mah and negotiates up. Some laptops (such as Macbooks) can actually trickle charge at this low rate when they are off without damaging or overheating the charger.
"Standard USB" (the term TL used) and USB-C are the same. I think you're referring to "Legacy USB" when you reference 2.0/3.0 (also, I think you mean USB A/B here).
Yes, I was using "specification" as it is more commonly known. My reference to "standard" USB is Type A which is the most common USB port on desktops and laptops (see attached image for clarification).
Type B is not even in the discussion.
I have to disagree; Type A and C are not the same thing. Not visually or specs wise (data/power delivery). Completely different standards altogether.
I was saying I have never seen a laptop charged via Type A port before, only Type C, and that is an important distinction so using "USB" go vaguely and generically can create confusion.
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Newer is relative. HP, Lenovo, and Apple made the transition 9-10 years ago. I have a 9 year old HP Spectre that uses USB charging. Also, in many cases, on laptops of these brands, all the USB ports (except legacy ports) supported charging.
Also, newer Apple Macbook Pros come with proprietary magsafe 3 chargers and still support USB charging. As does many Thinkpads including the T470, T570, X270, 370 Yoga (all of which were ~2018 era).
True, "newer" is relative but it doesn't take a genius to figure out that it really doesn't cover machine that are like 10 years old. I typically refer to machines that were built in the last 5 years as newer. I wasn't covering Macs in my post and also even though the Type C has been around about a decade, the number or makes and models that utilized it was hardly high enough to consider it a common feature.
From the machines I worked on in the last 2.5 years different makes and models, only the ones manufactured in the last 5 years seem to have at least 1 Type-C port (again only Windows laptops).
I do agree, since Mac is a single brand and typically quicker with newer technology, they had adopted it quicker throughout they available models.
I don't typically separate or identify USB Type A/B as "legacy", I only refer to USB 1.x and 2.x as "legacy" as they are almost identical with the exception of 2.x supporting flash drives and arguably the most common port with older machines still in use today. This opinion is based on dozens of different desktops and laptops I work on each month and 98% of the machines are 10 years old or newer.
What I don't quite agree on is the bold part. Does your laptop actually supports charging via Type A/B port? I have only seen little devices and smartphones charged via Type A/B ports, Type C for charging bigger devices like laptops but if I am mistaken, please provide a make and model, I'd like to check it out.
2018 definitely falls into the "newer" category for me. Also, when you say all those models support USB charging, again what USB were you referring to?
I was never disagreeing with Type-C being used for charging laptops, that is/has been the case for as long as it has been available but the only exception is not every USB-C port may support "charging".
This is not due to a restriction of the Type-C but more so the port due to the OEM's manufacturing. I have seen quite a few cases of HPs, Lenovos and Dells where without their OEM USB-C charger, they'd not charge.
On the flipside, I used Apple USB-C chargers to charge/power Windows laptops that use Type-C for power.
I just can't tell which is more common practice amongst OEMs, using generic chargers or proprietary but proprietary ones definitely exist. That is all I am going to write on this. Each reader can take whatever they want from it.
Last edited by TurcoLoco; 05-15-2023 at 09:09 PM..
It can destroy a plastic laptop when the battery heats up.I had one where the screen started to come apart right where it sat over the battery when it was closed.It was a dell laptop.
It can destroy a plastic laptop when the battery heats up.I had one where the screen started to come apart right where it sat over the battery when it was closed.It was a dell laptop.
The actual screen? That is interesting.
The most common side effect of bloated/blown up battery is typically non-working or glitchy touchpad.
That is typically the case with both Mac and Windows laptops as touchpad typically sits right above the battery so when the battery expands, it pushes against the touchpad and either temporarily or in some cases, permanently damages it.
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