Laptop won't turn on if the battery is plugged in (black magic?)

Hi, I'm quite an expert and savvy about PC's and notebooks, I even repair hardware sometimes, but this problem is driving me nuts. I have a lenovo Y510P notebook, Windows 10. It's been working just fine all last 7 years, normally with the AC charger plugged in and the battery as well, but in "life mode", which charges the battery up to 60% and then it doesn't charge it anymore. So, the battery has been barely used, theoretically. Last week, suddenly, I turned on the laptop but it wouldn't do anything, it would stay dead, no charging light, no LEDs at all.

So, I unplugged the AC charger, removed the battery, plugged everything back again, but still, 100% dead, no charging lights, no LEDs, nothing. So I thought: ok, the battery is empty and the Lenovo AC charger magically died last night. I tried an ASUS charger with same voltage, nothing. I took the Lenovo AC charger, tried it on another notebook, worked just fine. So, the Lenovo charger was working fine. Then it must be the battery, I thought, somehow it's not only dead, but also faulty in a way that if it's even plugged in, it won't let the notebook boot up.

I removed the battery, plugged the Lenovo AC charger, pushed the ON button, and to my surprise, nothing, no response, completely dead. Then I did the opposite, plugged in the battery, removed AC charger, nothing, same result. I was starting to think the MoBo magically died last night. I removed the battery, and tried the Lenovo AC charger on another laptop to double check and it worked just fine. I was about to officially declare the Y510P 100% dead overnight, but I tried a few more times with just the AC charger, and suddenly, it turned on after 5 minutes trying. Wow, I was really bugged...
What the hell was going on?
The Lenovo AC charger works only at times?
Also the battery is completely dead?
Two major problems appearing overnight?

I started to turn the Y510P off, then turned it on back again several times. Worked every single time. So, it seemed it was the battery, which was faulty, but then, why it didn't turn on when it didn't have the battery plugged in a few minutes ago? Why it suddenly started to work?

So, I inserted the battery back again, that broke it again, laptop completely dead. Removed the battery, plugged in the AC, nothing, completely dead. OK, the battery seems to be so faulty it won't let the laptop boot up, but not only that, it will "infect" the laptop for a few minutes and even after being removed it won't let it turn on. Sounds like black magic. Tried and tried until it started to work again.

Now, I've been using the laptop without the battery, only on AC, for the last week, and it has turned on every single time. So, one could think it's simply the battery. But, can you explain to me why, after plugging the battery in and removing it, the laptop won't turn on for a few minutes, on AC and everything?

During this "dead" time after removing the apparently dead battery, I've tried to push the ON button to clear CMOS, but nothing, it really looks like the battery makes the laptop sick and dead for a few minutes, and then it recovers and can respond.

Any explanation?
It could all be reduced to "faulty battery", but the "after dead" time doesn't fit, or at least I don't understand it and doesn't make sense to me.

What I can guarantee is that the charger works fine since I've been turning the laptop on during a whole week a lot without a single problem. Today I plugged the battery, one week later, and broke the laptop again, with the corresponding "dead period", until it works fine again on AC.

Dead CMOS battery, maybe?

A quick Web search suggests that it is soldered to the motherboard, unfortunately.

I was going to ask the same thing.

Unplug battery and power lead and hold down the power button for a minimum of 15 seconds. Then connect back up.

As the battery is DC, the charger has to step down and convert from AC to store power into the cells. So if the adapter is starting to cause problems, it may not be able to switch the current. I would get a multimeter on the end of the charger lead and see if you are getting the switchable feed on both sides of the wires. Make sure you know what youre doing here

As you probably already know, a battery will only show a + voltage if multimeter connected to correct polarity. So a fully charged 6 cell laptop battery is typically 10.8v charged and about 9v flat. This is a cut off voltage so you get constant power all the way to 0%. If the Lithium Ion cells go any lower than 3.2 to 3.0v each, you will knacker the cells. So again you could point the battery problem, to a broken down adapter.

Trouble is, at the time Lithium Ions capacity wasnt great and rather than use a quality, high mah cell. They cheat and use lower spec 18650's in parallel, which halfs the voltage and doubles the milliamps.

Also have a check of the pins on the under side of laptop and also battery pins and make sure they are all clean. Some electrical cleaner and a toothbrush is good. Brake Cleaner works well too

Good luck

I have almost same problem with a Sony Vaio laptop. It was from my nephew and he used it with a damaged battery and I think it may have damaged the internal power supply.
I have replaced the battery and it work with it. The problem is the internal power supply. The external power supply (19VDC) is converted internally into 12VDC and 5VDC (and maybe into -5VDC).
It has an overload protection (due to battery fault) that cuts the power and the computer don't even start without a battery.
My Sony has a defective that cuts the internal PS but the computer remains on due to the battery.
Then you shut down, remove the external PS, wait 1 minute and plug it again and, if I'm lucky, it begins to charge the battery.

I have seen many repair videos and it's not a easy fix.
A total BIOS reset is one of the possible fix. Other is to set from partially charge (60%) to full charge.

My recommendation is to check the battery voltage. On a 3+3 cells battery it should be between 10.8 and 12.6V
On my battery, the output is on the fist and last slot.
Hope it's a battery and not the internal PS

Good information Megahertz

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Just to confirm what Megahertz said earlier about the voltages.

I did a bit of testing today so have some useless information if anybody wants to have a read

I have done a complete discharge/charge cycle on a single 18650 2000mah Samsung cell. Its from an old Dewalt drill. Its been sat in a box for the last 3 years so this is an ideal test to see what kind of condition shes in.
First did a volt check and then a discharge to 3.0 volts @ 0.5 amps. Then charge at rated capacity, 2 amps.

Initial voltage of single cell = 4.05 volts
Total discharge capacity at 0.5amps = 1536 mah's
Voltage cutoff = 3.0 volts
Initial voltage at 2.0amp charge = 3.0-3.5-4.0-4.1 volts
Full charge voltage cut off = 4.2 volts
Total charge capacity at 2.0amps = 1786 mah's
Total charge time = 1 hour 41 minutes
Voltage check after charge = 4.16 volts

Im well impressed the cell had lost basically nothing in 3 years. 1500 out and almost 1800 back in. Kind of correlates to the voltages initially.

If that was a 1.2 Nimh in storage, it would have gone flat after about a month. Useless they are. Nicads were slightly different. For total storage hydrides like to be kept fully charged, whereas the old cadnium, was best discharged to total dead (with a bulb). Remember the awful memory fade Nicads had if you didnt manage them properly? Thats why the total discharge was good unless using them.

Trying to think what i can run off this single 18650? I dont vape so thats out the question. Make a torch? Mini light for PC case? Haha i dunno

Have a good evening all

Peace

bobkn said:

Dead CMOS battery, maybe?

A quick Web search suggests that it is soldered to the motherboard, unfortunately.

How could a dead battery make it behave like that?

Only when you insert the battery, then remove it, it enters in a "limbo" for 5 minutes or so where nothing you do will turn it on, then suddenly it rises from hell and starts working. You can unplug it from AC, plug it, whatever, it will turn on every single time, as long as you have plugged the AC of course, because the battery remains removed.

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Jacee said:

Did you unplug all peripherals while draining the power?

Yes, no USB is attached during the tests.

I will answer the rest of you tomorrow, thank you so much for participating, I hope we find an explanation to this really weird behavior. I'm also knowledgeable in electronics and electricity, so I already checked the battery and there were like 10V something between positive and negative. As I said, this battery has been for 7 years constantly in "battery life span" mode, which charges the battery to 60% and then stops charging, and stays like that forever. Like twice I year it gets charged due to battery dropping to 53%. But, as far as I know, the battery should be almost brand new.

rambomhtri said:

How could a dead battery make it behave like that?

(snip)

I have no idea what I was thinking. Not a chance.

I suppose that a replacement battery would be expensive, so a casual test may not be in the cards.

Indeed. I friend of mine had a laptop that it would not boot no matter what until we replaced its CMOS battery.

eLPuSHeR said:

Indeed. I friend of mine had a laptop that it would not boot no matter what until we replaced its CMOS battery.

Yeah, I've seen that myself. I guess I will have to check the battery, but I'm quite sure I already did when I disassembled it and the battery was perfectly fine. Anyways, a problem with the CMOS battery would not explain why if I plug in the battery, the laptop won't boot no matter if I wait, or if AC is plugged or not. So, I guess it's not quite that, don't you agree?