Ok to remove built-in Lenovo laptop battery?

Delly10 said:

What does this mean would happen if the main battery was removed for a few months? Would the functions normally performed by a CMOS battery simply be restored once the battery is reinstalled?

A bit of an example, I have a Toshiba Satellite white Notebook from aways back, has MS-DOS 6 and Windows 3.1 from early to mid-'90s. The main battery is dead but it also maintains the BIOS user settings on the CMOS. Every time I use it I have to reset/re-identify the drives available and other things, otherwise it works perfectly fine on AC power. The point is the BIOS settings are stored on the CMOS which usually is maintained by a CR-2032 battery or maybe a smaller one but on some older ones can have only the one battery.

My Lenovo does not have a removable CMOS battery - it essentially has a rechargeable battery (I am guessing it is built into the mobo rather than physically being removable). Obviously it gets charged from the mains or main battery. I have no idea what would happen after months of storage with a flat battery.

As @dalchina says, it is usually pretty easy to remove the main battery from most Lenovos - the case is easy to remove, and the battery is easily accessible.

Contrast that with my HP laptop where a 10kg sledgehammer is just about the only way of accessing parts LOL.

Regarding removable CMOS batteries, it really pisses me off that the CMOS battery is often on the "wrong side" of the mobo - you remove the cover, and it is not accessible - you have to remove the whole mobo disconnecting lots of things to get at it. This is a cynical design by manufacturers so they can charge users exorbitant rates to do a simple job!

This thread certainly went south. sorry I brought it up.

Your Lenovo IdeaPad 3-15IIL05 Does have a cmos battery. The main battery has nothing to do with it.
It is under the main board and the replacement procedure is exactly the same as per the video I linked you too.
It is not the coin style in your case, I only reffered to it like that because a 5 year old could do it in a desktop.
Below is the link to your exact cmos battery. $11.00 US

Robot or human?

When your cmos battery goes dead or is replaced, All your hardware configurations are "forgotten' and must be reset manually in the bios or it will not boot to windows. When I say "your", I mean your lenovo specificly My initial response to your post was simply somethingI I would do myself. It is your laptop to do with what you wish. Unused electronic components will corrode prematurely. A constant voltage supply will help prevent that. It is electronics 101.

The CMOS battery in the image provided may be a CR-2032 but could be another size, have seen 2 or 3 connected together in series, sizes such as used in small flashlights. It's simply encapsulated and has the 2 leads/wires welded to it, not soldered. I've peeled the plastic-type material off a few to see if they were otherwise usable but they weren't due to the wires. The wires connect to the mainboard instead of the battery setting in a socket like on desktop boards.

cereberus said:

My HP laptop where a 10kg sledgehammer is just about the only way of accessing parts LOL.

Regarding removable CMOS batteries, it really pisses me off that the CMOS battery is often on the "wrong side" of the mobo - you remove the cover, and it is not accessible - you have to remove the whole mobo disconnecting lots of things to get at it. This is a cynical design by manufacturers so they can charge users exorbitant rates to do a simple job!

My nephew gave me an old HP laptop.
The CMOS battery was quite easy to access and needed to be replaced. The CR2032 is soldered to a cable. Why not as most CMOS batteries on a socket?
The CPU and GPU heat sink was completely clogged with dust. To have access to the fan and heat sink I had to disassemble it completely, even the screen had to be removed. A Nightmare.
I have seen a HP laptop that to access the HDD you have to to disassemble almost it it completely.
Most of this stupid designs are on HP home laptops. Business laptops have a much better design.

On my Asus it was so simple to remove the fan and clean the heat sink. And the CR2032 CMOS battery is on a socket.

The use of the encapsulated batteries saves space on the motherboard and the seemingly-miniscule weight saving makes a difference when all such savings are made and to the total weight of the Notebook/Laptop. The physical size of the socket also has to be considered in the designing of the computer, think of the different sizes of the Notebooks, 11", 12", 13", 14", 15", 17" and now 16". I have all except the 11" and 16", mostly rehabbed from what people have given me for parts. Used to have an 11" but when Windows started needed more space the 32GB wasn't enough to continue with.

Delly10 said:

I noticed that the battery drains itself (even after just a few months), even though the computer is shut down (not in sleep mode)

Lenovo support recently told me that losing 2% of battery charge every day when shutdown is normal.
My Lenovo IdeaPad does that.

Delly10 said:

Upon reading that lithium batteries become damaged that way, and are unsafe to use afterwards, ...

Lithium batteries can physically degrade at 0% charge but not always. In your case, I would expect some degradation but there's no telling how much.

- I've recharged some fully-drained batteries that have been fine afterwards & have kept working for years.
- I've recharged some fully-drained batteries and they've only been able to keep the computer running for little more than the blink of an eye.
- I've attempted to recharge some fully-drained batteries but they have failed to recharge.

I suggest that you connect it to power and find out if it recharges properly while you are around to keep an eye on it.
And, after its fully charged again, find out the ratio of its current full charge to its design charge by running a PowerCfg battery report.

Code:

PowerCfg /batteryreport /output E:\PowerData\BatteryReport.html /Duration 1

using a real folder on your computer in place of my E:\PowerData path.
There is a lot of other data in a battery report but all you are interested in are its Full charge capacity & its Design capacity.


Then try using it for a while to see if it behaves itself. If it has recharged alright, if it has a decent ratio of Full charge capacity to Design capacity and if it powers the computer for a decent period then there is no reason to be worried about battery damage.
I've deliberately used decent because there are no specific numbers that are right or wrong.
- If that ratio is below 50% then I make a note to start thinking about maybe buying a replacement someday.
- If it no longer powers my computer for as long as I regard as essential, but used to, then I buy a replacement.

Delly10 said:

this one is built-in, requiring removal of the laptop's bottom cover, and then several screws from a circuit board

Your Lenovo Hardware Maintenance Manual should give you decent guidance when doing this job. I downloaded mine from the same Lenovo support section that I use for downloading drivers & a user manual.
I have never heard of a laptop that could not be used without its battery being fitted but I think you should ask Lenovo support or see if you can get an authoritative statement about it in the Lenovo user forums.

Delly10 said:

I restarted with all cables removed and pressed F1 when the Lenovo logo came up

On my own Lenovo IdeaPad, it's the F2 key. It is not Fn-F2 despite having a Fn key on my keyboard. It is just F2.
And I think all other Lenovo Ideapads use the same as the Bios key. See Recommended way to enter BIOS - ideapad - Lenovo Support GB

My own Lenovo IdeaPad's Bios does have a disable battery setting in the Bios, Configuration section.
But it states quite clearly that this is merely a temporary disabling. So it is not suitable for what you have in mind.

Delly10 said:

What does this mean would happen if the main battery was removed for a few months? Would the functions normally performed by a CMOS battery simply be restored once the battery is reinstalled?

Yes, the functions would be restored and would work again but you would have to set up some of its entries again.
So it is always worth recording Bios settings in case they get lost. I take photos of each Bios section when I get a new computer, when its Bios gets updated & when I change any settings.


I noticed some discussion of the separate subject of CMOS batteries earlier on in the thread.
My own Lenovo IdeaPad does not have one.
But some laptops do [my Dell Inspiron laptop does] so there's no telling whether yours does or not.
If your computer has a CMOS battery, your Lenovo Hardware Maintenance Manual should refer to its replacement [possibly just calling it a "coin-cell" battery].
That UTube video one shows a CMOS battery on the left-hand side.

Delly10 said:

I couldn't find where the SSD drive was

Similarly, your Lenovo Hardware Maintenance Manual should resolve that matter.
You might, like many of us, have an M.2 card as your SSD. An M.2 card is very small, about 2cm [3/4inches] wide and a maximum of about 8cm [3inches] long. Here's mine. It's a replacement. The original Lenovo one was half the length [but, like all M.2 cards, the same width] and was completely hidden by its metal heat shield.

And here is the shorter M.2 card my Lenovo IdeaPad came with and its heat shield.

That UTube video might show your M.2 SSD in the middle of the picture but it is not clear enough for me to be sure. It is definitely an M.2 device of some kind and it's the same size as the M.2 SSD my Lenovo IdeaPad came with.

NVMe M.2 cards look about the same as SATA M.2 cards. You have to look at their connections to see the difference - the layout of gaps between individual connection pins differs.
NVMe M.2 cards have really become the M.2 SSD standard these days. They are cheaper & faster and people bother making larger & larger ones whilst they've mostly stopped making SATA M.2 cards bigger than 1TB.
And NVMe M.2 cards have really become the standard for laptop 'disks'. My 2026 Dell Inspiron has an M.2 SATA 'disk' and when that computer eventually dies I do not expect to see another one.


Incidentally, that UTube video also shows what seem to me to be an unused 2.5inch SSD frame. That holds out the possibility that it can fit both an M.2 SSD [as the main OS & applications drive] and a cheaper yet larger 2.5inch SSD [for, say, mp3 files & video files].

- My Dell Inspiron laptop also has that capability & I find it extremely useful.
- My own Lenovo IdeaPad does not.
Your original specs should tell you if your computer has that capability.
And your Lenovo Hardware Maintenance Manual would also resolve that matter by including instructions for replacing both types of SSD.


Best of luck,
Denis

Try3 said:

Lenovo support recently told me that losing 2% of battery charge every day when shutdown is normal.
My Lenovo IdeaPad does that.


Lithium batteries can physically degrade at 0% charge but not always. In your case, I would expect some degradation but there's no telling how much.

- I've recharged some fully-drained batteries that have been fine afterwards & have kept working for years.
- I've recharged some fully-drained batteries and they've only been able to keep the computer running for little more than the blink of an eye.
- I've attempted to recharge some fully-drained batteries but they have failed to recharge.

I suggest that you connect it to power and find out if it recharges properly while you are around to keep an eye on it.
And, after its fully charged again, find out the ratio of its current full charge to its design charge by running a PowerCfg battery report.

Code:

PowerCfg /batteryreport /output E:\PowerData\BatteryReport.html /Duration 1

using a real folder on your computer in place of my E:\PowerData path.
There is a lot of other data in a battery report but all you are interested in are its Full charge capacity & its Design capacity.

Then try using it for a while to see if it behaves itself. If it has recharged alright, if it has a decent ratio of Full charge capacity to Design capacity and if it powers the computer for a decent period then there is no reason to be worried about battery damage.
I've deliberately used decent because there are no specific numbers that are right or wrong.
- If that ratio is below 50% then I make a note to start thinking about maybe buying a replacement someday.
- If it no longer powers my computer for as long as I regard as essential, but used to, then I buy a replacement.


Your Lenovo Hardware Maintenance Manual should give you decent guidance when doing this job. I downloaded mine from the same Lenovo support section that I use for downloading drivers & a user manual.
I have never heard of a laptop that could not be used without its battery being fitted but I think you should ask Lenovo support or see if you can get an authoritative statement about it in the Lenovo user forums.


On my own Lenovo IdeaPad, it's the F2 key. It is not Fn-F2 despite having a Fn key on my keyboard. It is just F2.
And I think all other Lenovo Ideapads use the same as the Bios key. See Recommended way to enter BIOS - ideapad - Lenovo Support GB

My own Lenovo IdeaPad's Bios does have a disable battery setting in the Bios, Configuration section.
But it states quite clearly that this is merely a temporary disabling. So it is not suitable for what you have in mind.



Yes, the functions would be restored and would work again but you would have to set up some of its entries again.
So it is always worth recording Bios settings in case they get lost. I take photos of each Bios section when I get a new computer, when its Bios gets updated & when I change any settings.


I noticed some discussion of the separate subject of CMOS batteries earlier on in the thread.
My own Lenovo IdeaPad does not have one.
But some laptops do [my Dell Inspiron laptop does] so there's no telling whether yours does or not.
If your computer has a CMOS battery, your Lenovo Hardware Maintenance Manual should refer to its replacement [possibly just calling it a "coin-cell" battery].
That UTube video one shows a CMOS battery in the left side.

Similarly, your Lenovo Hardware Maintenance Manual should resolve that matter.
You might, like many of us, have an M.2 card as your SSD. An M.2 card is very small, about 2cm [3/4inches] wide and a maximum of about 7cm [3inches] long. Here's mine. It's a replacement. The original Lenovo one was half the length [but, like all M.2 cards, the same width] and was completely hidden by its metal heat shield.

That UTube video might show your M.2 SSD in the middle of the picture but it is not clear enough for me to be sure. It is definitely an M.2 device of some kind and it's the same size as the M.2 SSD my Lenovo IdeaPad came with.

NVMe M.2 cards look about the same as SATA M.2 cards. You have to look at their connections to see the difference - the layout of gaps between individual connection pins differs.
NVMe M.2 cards have really become the M.2 SSD standard these days. They are cheaper & faster and people bother making larger & larger ones whilst they've mostly stopped making SATA M.2 cards bigger than 1TB.
And NVMe M.2 cards have really become the standard for laptop 'disks'. My 2026 Dell Inspiron has an M.2 SATA 'disk' and when that computer eventually dies I do not expect to see another one.


Incidentally, that UTube video also shows what seem to me to be an unused 2.5inch SSD frame. That holds out the possibility that it can fit both an M.2 SSD [as the main OS & applications drive] and a cheaper yet larger 2.5inch SSD [for, say, mp3 files & video files].

- My Dell Inspiron laptop also has that capability & I find it extremely useful.
- My own Lenovo IdeaPad does not.
Your original specs should tell you if your computer has that capability.
And your Lenovo Hardware Maintenance Manual would also resolve that matter by including instructions for replacing both types of SSD.

Best of luck,
Denis

Denis,
I totally agree with your explanation. Indeed it is basically what I wrote on my posts above (see post #9)

"I would only remove the Lenovo battery if it only hold charge for less than an hour.
If it does hold charge for more than an hour it may not be 100% but it still work. In this case, once a month put the battery to charge. If the laptop has a battery life extend fuction (Max charge to 80%) enable it. "

One of my daily-use Dell Notebooks [Vostro 3400] has that additional place for a 2.5" drive, haven't decided on one of the 1TB HDDs I have salvaged from otherwise junked Notebooks or a new SSD for power considerations. The boot/system drive is a 256GB NVMe.