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What's DOS?
Posts: 1
Registered: ‎04-22-2015
Location: Canada
Views: 4,320
Message 1 of 4

Y40-70, turns off when unplugged.

Hello Everyone.

I bought a Lenovo y40-70 computer in early January and so far I've really loved it. But just the other day, I started having some strange issues that I'm frankly at a loss to solve. It's progressed in several stages, and I'm a little concerned for my laptop. I wanted to know if anyone had any fixes/ suggestions:


1- First thing I noticed was that the battery icon would not show the battery 'filling' up while it was plugged in. I remember reading that the battery icon doesn't always refresh, and as the battery said it was charging, I didn't worry.


2- Again, yesterday. After using my computer without the charger for some time, I plugged it in to work. It was plugged in for a good two hours, and yet the battery continued to read at 17%. It wasn't going up.


3- I unplugged my computer to check on the battery status. My entire computer shut down (Instant off, black screen, fans stopped etc). Turned it on while it was still unplugged to watch it reboot just fine. Battery was still at 17%


4- Repeated the process of plugging/unplugging the computer to find that the computer shut off everytime. The battery did wind up filling to 94%, so it did charge. I finished up my work for the day and went to bed.


5- Tried to start my laptop, unplugged, today while I was out. It would not turn on, despite the fact that I know it had a full battery before I put it away. I then plugged it in and tried again. It turned on, displaying a near full battery. Removing the plug while the computer was still on, once again instantly shuts it off. Several more retries and it's pretty clear I cannot use my computer unless it is plugged in.


And that's pretty indicative of the situation so far. I don't know if this is just an issue of a faulty battery, or if something else is at work, but I was wondering if anyone had any advice before I called in support.



Retired Support Specialist
Posts: 4,447
Registered: ‎04-22-2013
Location: Philippines
Views: 4,304
Message 2 of 4

Re: Y40-70, turns off when unplugged.

Hi ritzbitz,


Welcome to Lenovo Community Forums!


Can you try to Manually resetting  the battery out.

    Boot the System into BIOS by hitting F2 when you power ON the computer.

    Now stay in BIOS and let the computer run with Only the Battery in that mode.

    Let the computer turn OFF By itself due to battery power loss.

    BIOS Does not have any feature to turn off the system on minimal charge but It will be OFF once it is Fully Drained.

    Now Let the computer OFF and charge the computer with the AC adapter for 30 Mins.


    Power ON the computer and Let it charge to a 100% then Observe if that resolves the Issue.


Hope this helps



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Former Employee
Posts: 1,664
Registered: ‎09-16-2014
Location: US
Views: 3,307
Message 3 of 4

Re: Y40-70, turns off when unplugged.

In response to customer reports of unexpected battery gauge behavior on Y40-70 and Y40-80 laptops, Lenovo determined the battery gauge software is performing as expected. The unusual gauge results being reported are a reflection of the battery reaching end of life.


Lenovo has released a Service TIP to assist customers with obtaining battery replacements under warranty, or if out of warranty, to find a replacement battery from Lenovo-approved vendors. The Service TIP can be found here:


The part numbers for Y40-70/80 batteries are:

Y40 SP/A L13M4P01 7.4V48Wh 4cell bty (Y40-70/Y40-80) 121500248

Y40 LG L13L4P01 7.4V48Wh 4cell bty (Y40-70/Y40-80) 121500249 substitute part 121500251

Y40 CP/C L13C4P01 7.4V48Wh 4cell bty (Y40-70/Y40-80) 121500259 substitute part 121500251


To determine which battery came with your Y40 notebook, instructions for removing the bottom cover can be found in the Hardware Maintenance Manual pdf here. An alternative to opening your system (which does not void warranty) is to search for batteries using the model/product number located on the bottom cover.


Thank you,

What's DOS?
Posts: 1
Registered: ‎05-08-2018
Location: CA
Views: 1,999
Message 4 of 4

Re: Y40-70, turns off when unplugged.

I have just recently bought a new battery, and updated the BIOS. Still having this same problem.

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