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How to calibrate your laptop’s battery and fix inaccurate wear info

By Douglas Black , last updated on September 12, 2019

The issue I’ve been coming across recently seems to be mostly with Dell’s XPS line of laptops, though it can certainly affect others: My new XPS 13 9370, XPS 15 9575, and XPS 15 9570 showed 8, 14.5, and 10% battery wear out-of-the-box, respectively (a battery wear of 10% means that the battery is only able to charge to about 90% of its rated capacity).

Normally, batteries will only show this much wear after a year of heavy usage, and it isn’t something you should accept in a new laptop. I realized something was up when every single XPS 15 I checked out new had around 10% battery wear reported, however.

Battery calibration hasn’t been much of a necessity since lithium-ion batteries got so much smarter over the past few years. Thus, even as someone who considers themselves to know quite a bit about notebooks, properly calibrating the battery in my new XPS laptops (showing incorrect wear percentages out of the box) was something I had to do a bit of reading up on combined with some trial and error to get right, and so I thought I would write a brief guide on how to do it right the first time.

Following this protocol, I was able to reduce the reported wear levels significantly to the low single-digits and recover a good deal of battery life.

Checking your battery’s reported wear

Before bothering with a calibration, it’s necessary to check the reported health of your battery. If your battery is new and showing less than 95% of its original capacity then it is probably worth recalibrating.

Go to the Start menu and search “cmd” to show the Command Prompt (PowerShell will do fine as well). Right-click the search result to run your choice of app as an administrator. Copy and paste the following line into the command line: powercfg /batteryreport

The battery health report will be output to the Windows\system32 folder by default.

Copy the directory path and paste it into your favourite web browser to view it. Once it opens, you can scroll down a bit and you should see your battery’s health as a function of design capacity (rated capacity) and full charge capacity (actual amount the battery reports it is able to hold).

After calibration. Before calibration, the full charge capacity was only 87,000 mWh, or less than 90% of advertised.

By doing some quick math you should be able to see how healthy your battery currently is. Technically it is not good to fully charge and discharge a Li-Ion battery often (which is what calibration requires), so if your battery is not new and the wear percentage seems reasonable, it may be best to leave it. If you see only 90% of capacity on a new laptop, however, then this guide will definitely help.

The procedure

Step 1:

First, you will need to let your laptop charge to its “full” capacity. OEMs like Dell and Lenovo allow the user to set charging-thresholds on the battery in order to preserve the battery health (this is a very good practice that I encourage all OEMs to follow). Thus, to charge the laptop fully, you’ll need to find that setting and set your charging threshold temporarily to 100%. On XPS machines, this is done through Dell Power Manager or the BIOS.

You’ll need to set the charging behavior to “Standard” or change the slider manually to 100% to complete the first step. Once this is done, make sure your laptop is plugged-in and allow it to charge completely.

Step 2:

Next, you need to let the battery completely discharge until forced shut-off (not just hibernation). There are a few ways to do this, but my favourite method is the simplest: Restart the laptop in BIOS mode, then go out of the house for the day. With this method, you don’t need to worry about the laptop going to sleep or hibernating as these features are not enabled when viewing the BIOS. Additionally, power-saving states are not enabled for the CPU when in the BIOS either, meaning the laptop will run down significantly faster than it would in Windows under normal usage.

You could also use the laptop normally and let it run down until it automatically hibernates, then leave it in BIOS as described above as well. This requires your turn off all of the sleep and hibernation timers in the Power Options control panel first, however.

Step 3:

WAIT. Do not immediately charge the laptop; be sure the laptop has been sitting cool and unplugged for 3-5 hours before the next step. Failing to perform this step can result in making your reported battery wear worse.

Step 4:

Plug the laptop in and let it charge to maximum uninterrupted. You should be able to use the laptop in Windows at this point, but I let it charge in BIOS out of superstition. When you generate your battery report again, you should (hopefully) see a much higher rated capacity for your new battery.


That’s it! Using this method I was able to reduce my 9575 reporting 14% wear down to 4%, my 9570 reporting 10% down to 3.8%, and my 9370 reporting 8% wear down to 4%, and I hope it fixes the problem for you simply as well. As always, try to practice good battery care to prolong their lives: Keep them cool, don’t run them dry, and don’t charge them to maximum often. If you are interested in reading more about safety and care for Li-Ion batteries, you can check out this guide for further reading.

Did you also get an XPS laptop with double-digit battery wear? Please share your results in the comments.



Based in Hong Kong, Douglas Black is a veteran editor of Notebookcheck, university lecturer, researcher, and writer.


  1. imin

    July 18, 2018 at 11:46 am

    Nice article! But shouldn't Dell at least have a better QC prior to releasing their laptop?

    • Douglas Black

      July 18, 2018 at 11:48 am

      Absolutely — the lack of QC is, imo, one of the main reasons why companies like Apple can exist despite being noncompetitive in almost every other arena. I would guess that whoever has been supplying their batteries is the same company for all 3 XPS machines, thus why they all have incorrect wear/capacities.

  2. Matthias

    August 8, 2018 at 12:12 pm

    worked for me perfectly on my new xps 9570. from 87 to 93mWh.

    If i repeat this process, will i get to 97mWh at some point or is 93 the best result i can get for my battery and it will only get worse from this point?

    • Andrei Girbea

      August 10, 2018 at 2:11 pm

      As far as I know, it shouldn't get worse, so you could try it one more time, but it won't probably do much. 93/97 is not bad though.

      Update: Also see Kirikshi's the reply below.

      • kirikshi

        November 28, 2018 at 2:22 am

        That is not true, as any Li-Ion battery is very susceptible to complete discharge.
        It is said to resist quite low (1-2 dozens) of complete harsh discharges (as in the article) till its completely "dead" in terms of residual capacity. So, this experiment (albeit it can help with the calibration) is not a fortnight trick. No one promised that following complete discharge will damage battery (decrease capacity) less, than it rescales the calibration.
        Another reason not to risk – Li-Ion batteries show thermoelecric effect – voltage of a unified battery depends on temperature. (example: https://www.nature.com/articles/ncomms4942#f1) As a result, if you drop your charge to critical level and afterwards your laptop battery cools down – it goes below critical level, damaging the cell.
        All of this means that the procedure, even if it leads to calibration with winning around 5-10% of capacity, shouldn`t be implemented often (more than 4-5 times for the battery life).

        • Douglas Black

          November 28, 2018 at 5:22 am

          That is correct — I hoped I made it clear in the article not to do this unless your battery should be brand new but is showing unusual wear (such as the case with many Dell laptops).

        • Andrei Girbea

          November 28, 2018 at 1:29 pm

          Thanks, you're right, I was only suggesting performing this one more time. I'll edit the initial reply to make it more clearly.

  3. Will

    September 2, 2018 at 9:23 pm

    Worked great for me! Went from 90% to 96% on a brand new XPS 15 9570. Thank you!!!

  4. hp support

    September 26, 2018 at 2:28 pm

    Turn on the computer and immediately press the F2 key repeatedly, once every second until the HP PC Hardware Diagnostics UEFI menu displays. Click Component Tests in the main menu.

  5. Lacy

    November 10, 2018 at 4:28 pm

    Thanks for this article. I'm here because of my Dell XPS 15 9570, FullHD, 97Wh.
    The first weeks the battery last about 8-10h with my use case which look like this:
    60% Videos/Streams via LAN
    25% Office Work
    10% Music via external speakers
    05% Gaming

    After about ten weeks, the battery only last about 4-6h with the same use case.
    So, I just have done the "cmd" step, and the battery has a "full charged capacity"
    of 77Wh, compared to 97Wh! After ~twelve weeks just 80%! of the capacity is left.

    I hope with the steps the capacity will increase again, if not this was the first
    and last time buying such an expansive notebook from Dell…

    • Lacy

      November 13, 2018 at 12:29 am

      So, after 2.5 days, and about 6.times repeating the steps 1-4,
      the battery is now mostly "healed". From 77Wh to 89Wh in just a short time.

      I also know what one problem was.
      Like with the smartphones-batteries, I thought it would be okay to
      charge my notebook at about 15-20% up to 97-100%. But this notebook
      looks like it does not work with this way of charging.
      But, in my opinion the notebook should handle this kind of charging
      in a better way. I mean, I can not wait everytime to charge up to
      100% and then leave my flat.

      Thank you for this steps, saved my money for a new battery ;).

      • Douglas Black

        November 13, 2018 at 3:06 am

        I'm glad to see it worked itself out!

        • Terafile

          March 19, 2019 at 10:02 pm

          Just repeated this process 3 times with my 9575, but unfortunately my battery went from 13% of wear (laptop is only 4 month old and was shipped with 5.7%) to 23%. I discharged it from the full state in BIOS. Then I waited for 5-13 hours to discharge more and then didn't touch it when it was charging. What am I doing wrong? BTW the time I switched from charging from max 94% to 100% (and started using Manjaro Linux) I saw a drop in a capacity to that 13%, I've previously mentioned.
          BIOS 1.2.0 (latest)

  6. Bautista

    January 6, 2019 at 5:26 am

    Hi, I ve been checking the actual capacity, and it fell from 96000mah out of the box, till 88000, about 2 months later. The weird thing is that now after a full charge, I disconnect it and it inmediately drops from 100 to 95, or 98 in today's case. I did this calibration yesterday but didnt solve the problem!

    • Douglas Black

      January 6, 2019 at 7:23 am

      That sounds like it's what you're battery's actual capacity is. It isn't great but not malfunctioning yet

      • Terafile

        March 20, 2019 at 12:28 pm

        My 9575 on 1.2.0 bios (don't know if that matters) after 3 of these procedures went from 13.5 to 21.5 battery wear? I charged the laptop to 100% then opened bios and sit there till it powers off. Then I waited 5-10 hours and plugged back in to charge to 100%. Every time I opened the OS the battery capacity slowly had gone out. What am I doing wrong? Laptop is only 4 month old and was shipped with 5.7% wear.

        • Douglas Black

          April 29, 2019 at 8:46 pm

          sorry for the late reply. I would suggest calling for a new battery before your laptop is 6 months old – you may really have 21% battery wear, and batteries are usually only covered for the first 6 months of warranty. Tell them it's at 21.5% wear and it's running out much too soon, and they should help you out with a new one.

  7. Sanju

    March 23, 2019 at 12:49 pm

    I did so as you mentioned..but the wear level increased to 20% from 14% dell 4 cell 41mah battery purchased before 1 week. At first recharge wear level was 5% and my lappy automatically goes to hibernate at 37% and suddenly it show 8% then after wear level increased to 14 and now it's 20. Backup is approx 3 hours all settings are normal. Did I got the defective piece…it's nearly 4 months old manufactured as mentioned on box. I conslulted dell they took several tests and all tests were cleared successful…and told me to charge discharge some more cycles for stability. Should I opt for replacement as the retailer gives me full 1 year warranty at his shop. Can you suggest me what should I do….thanks

    • Douglas Black

      April 29, 2019 at 8:48 pm

      Sorry for the late reply! If you have a new battery with 14% wear that re-calibrated to 20%, I would return it to the shop indeed.

  8. just

    April 4, 2019 at 2:02 pm

    From 18% to 10% wear level

  9. M. Garrison

    May 6, 2019 at 4:20 am

    There is no way to keep the 9370 (XPS 13) from turning off at critical battery level (which cannot be set lower than 2% in advanced power settings) even if I am in BIOS. I keep turning it on and then it turns off after booting up again and again. I don't know if this impacts the calibration process. I calibrated it a week ago and gained 10% capacity (design is 52Wh and it had increased to nearly 48Wh) but three days later it dropped to 41Wh so I hesitatingly, as attempting it once more. One other question, the 9370 BIOS allows me to set charging between 50 and 90%. But when I do that it stops at 90%, gives me the message plugged in not charging but never leaves 90%. So it doesn't discharge down to 50% ever. Turned that off after a day setting at 90%. Is this a problem with Modern Sleep or can I change something in registry? I tried asking this on Dell without any luck.

  10. Daniel

    June 1, 2019 at 5:35 pm

    I did the steps from 1 to 4 for my XPS 9570 and I managed to decrease the wear from 10% to 4,3% (from 87MWh to almost 93Mwh).

    It is crucial to leave you laptop discharged for 3-5 hours before charging it again to full capacity.

    • Thomas

      September 26, 2019 at 4:45 pm


      First of all I would like to thank you for the guide. Unfortunately it has not been helpful for me. The battery in my X1 Extreme went down from 75MWh to 72MWh. Its design capacity is 80MWh and it only has 25 recharge cycles so far. I also mostly use the laptop plugged in with a 80% threshold activated. Does this mean my battery is faulty and should I file a claim for a new one? Or should I try to recalibrate the battery one more time? Thanks so much, your support is greatly appreciated.

      • Douglas Black

        September 26, 2019 at 5:06 pm

        Batteries are so mercurial that I almost feel like recalling this guide. I've successfully re-calibrated batteries with this process quite a few times, but mostly from Dell. Lenovo seems to play on the conservative side with their firmware (batteries included) I think, in order to keep things more reliable. Just a theory. After 25 cycles and you're at 72Wh though, I'd try recalibrating once more (leave it a good while to cool off before charging) before trying for a new battery.

        • Thomas

          September 26, 2019 at 5:20 pm

          Hi Douglas,

          Thanks so much for your quick reply. Will recalibrate one more time before trying for a new battery then. Thank you!

          • Douglas Black

            September 27, 2019 at 6:54 am

            welcome! wish you best of luck

  11. Alex

    June 13, 2019 at 10:20 pm

    Hi ,two days before I had a sudden battery failure. The first time that I did the recalibration to the battery following these steps I had a 0% wear and after 8 months of use my battery was at 94WHr / 97 Whr.

    After changing the battery I tried yesterday to calobrate my battery but I dont remember what I have done in the past . So yesterday I let it fully discharged after replacing the battery. Then recharged to full after 5 hours. Today I used the laptop and I let it to fully diacharged again and I charged it to 100% but the battery is 93Whr / 97.

    Will be a problem if I repeat the steps again – one more time ?

  12. Mahammed Ehab

    September 6, 2019 at 11:57 pm

    Your artical didnt help i still have the battery wear

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