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I recently purchased a new Li-ion battery for my HP Probook 4520s PC which claims to be 5200mAh/58Wh. When I ran battery scan with windows powershell, I saw that the capacity was 45Wh.

I was directed by the user manual to use the battery till 2% then fully charge the battery to 100% (The battery was at 72% when I bought it new). But the battery shuts down at 38% (From the 72%). I fully charged the battery and then try to use it to 2%, but It always shuts down before 10%.

I ran the battery scan now on powershell and discovered that the battery capacity has reduced to 40Wh. Photo of the Scan, Second Photo of Scan

How do I stop the battery from shutting down before 5/10%. And is there a way to increase the battery capacity back to 45Wh or even to the claimed capacity of 58Wh? Thank you.

scisamir
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    Is it truly new, or "been sitting in a warehouse for 15 years" new? Did it arrive with some charge or completely empty? – u1686_grawity Apr 15 '22 at 11:27
  • It is a new battery. It was manufactured on 29/11/2021. It was 72% charged when I purchased it. – scisamir Apr 15 '22 at 11:37
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    Try to return it or have it replaced. I have replaced batteries on my Laptops and they have always worked to full spec. Check your BIOS settings to see if you have Battery Threshold set and maybe set too low. – John Apr 15 '22 at 12:10
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    As @John mentioned, easiest way to resolve is to exchange it for a different one; I would run a battery hardware test via the BIOS'/UEFI firmware's built-in hardware diagnostics _(usually accessible via the BIOS/UEFI firmware settings or the BIOS/UEFI firmware boot menu)_. Rechargeable batteries always have a charge at manufacturing, but not a full charge, due to the physics of how rechargeable batteries work _(this is why it's recommended to charge a new rechargeable battery)_. Battery Wh capacity will decrease as amperage decreases from usage: `(5200/1000)*10.8v=Wh` _(mAh/1000=Ah) * V = Wh)_ – JW0914 Apr 15 '22 at 12:43
  • Thanks for your replies John and @JW0914. I don't think my laptop has the feature for battery diagnostic in its BIOS/UEFI – scisamir Apr 15 '22 at 13:54
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    @IdrisSamir there's not an option called [_Diagnostics_](https://imgur.com/a/IjOKPHZ)? Most laptops have built-in hardware diagnostics, and once selected, it boots into a diagnostic environment and begins a short test on all hardware components, one of which is the battery. You can stop the diagnostics test and just run it on the battery – JW0914 Apr 15 '22 at 16:49
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    Is it your OS that shuts down early or really the battery? If it is the battery, it is simply _empty_ (the shown percentage is just a guess done by the OS!). If it is the OS, you will have settings for changing that cutoff point. – Aganju Apr 15 '22 at 21:46
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    @Aganju OS battery percentage isn't a guess, it's a simple mathematical formula [Ohm's Law] – JW0914 Apr 20 '22 at 10:40

1 Answers1

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I've found this to be pretty typical behaviour of aftermarket batteries. These OEM knock-off's made in China (some even with OEM branded labelling) never quite perform as advertised.

I suspect it's due to not-quite-right (poorly designed/reverse engineered?) battery management circuitry and/or inferior (cheap) lithium cells - at least in comparison to the OEM equivalent.

The mAh/Wh always fall short to varying degrees (some sellers are better than others... if you find examples priced significantly lower, they've probably cheaped out with LiPo cells), the empty/0% state of charge tracking is off (by about 10%), and capacity drops VERY quickly when under load at low charge states (e.g. playing FHD video can drop you from 25% charge to a powerless state rather suddenly).

But for basic tasks/office work/web browsing they do the job. And as they say, you get what you pay for... these are typically much cheaper than OEM and conveniently are still available long after the big-brands ceased production.

My reccommendation is to;

  1. Always buy the largest capacity battery you can (and make sure they're LiIon cells, preferably from Japan or Korea) &

  2. Find that sweet spot for where it actually reaches 0%, and adjust your systems power management settings accordingly, to avoid sudden/unexpected shutdowns (e.g. set low power warning at 20%, etc.).

Far from ideal, I know, but I hope that helps.

user1138
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    There's nothing wrong with aftermarket laptop batteries _(it's simple physics)_. They, like most li-rechargeable packs, are clusters of 18650's and if an issue occurs, it's likely going to be with the firmware on the battery's PCB _(incl. overcharge protection)_ or lack of a pressure release function on the 18650's casing, not the chemistry itself. Laptop OEMs _(like printer OEMs with toner/ink)_ massively overcharge by 100%+ for batteries and there is no tangible benefit, quality or otherwise, to buying OEM vs aftermarket provided the aftermarket battery comes with a 1yr warranty – JW0914 Apr 15 '22 at 12:55
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    mAh/Wh can't fall short, as it's simple physics _([Ohm's Law](https://en.wikipedia.org/wiki/Ohm%27s_law))_: `(mAh/1000)*V=Wh` - as amperage decreases from usage, Wh available decrease _(e.g. watching GPU intensive video will use more amperage and drop available Wh accordingly, as Wh are relative to the amount of current [Amperage] remaining in the battery)_. Lithium batteries output their rated voltage until the contained amperage is exhausted, which is why lithium batteries are preferable to NiCad, or why non-rechargeable lithium batteries are preferable to alkaline batteries [AA, AAA, etc.] – JW0914 Apr 15 '22 at 13:08
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    Additional context also missing: Lithium batteries have a finite charge/discharge cycle _(~200)_ before they begin losing charge capacity; this is why it's recommended to only charge lithium batteries to 80% since it almost doubles the charge/discharge cycles compared to charging the battery to 100% full - it's common for laptop batteries _(OEM or aftermarket)_ to only have ~50% charge capacity after 1 - 2yrs and the charge capacity can be seen by running a laptop's built-in hardware diagnostics _(usually accessible via the BIOS/UEFI firmware settings or the BIOS/UEFI firmware boot menu)_ – JW0914 Apr 15 '22 at 13:19
  • @user1138; The battery manual says to use it to 2% before charging. I didn't charge it before using it for the first time. Could that be the cause of the problem? – scisamir Apr 15 '22 at 13:57
  • @IdrisSamir No. Please refer to my comments under your question and this answer – JW0914 Apr 15 '22 at 17:58
  • No Idris - that won't be the cause. For the War & Peace version of battery chemistry/electronics fundamentals read JDub's comments (or an Electrical Theory/Engineering textbook 8-P )... otherwise my answer still stands: most, but not all aftermarket laptop batteries are made the same - I've got stacks of them, pulled them apart, tested the cells and they can/do differ, wildly! Like I said, I've even seen some pretty rubbishy LiPo cells used in some. So again, if that price on eBay/AliExpress is too good to be true, it probably is! – user1138 Apr 16 '22 at 00:28
  • And even without defying Ohm's law, mAh/Wh CAN and DO fall short of the advertised capacity, irrespective of the system load - I've tested supposedly like for like cells and again they vary in performance. But to clarify, the battery management circuitry/PCB/firmware (call it what you will) and it's handling of state of charge (SoC) is more so the issue at low charge states under load. – user1138 Apr 16 '22 at 00:28
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    Just try to buy reasonable quality (look for ones with good reviews/lots of sales), look after it as JDub suggests (adjust your systems power management settings to help in this regard), & you'll get plenty of life out of it. Then, if you've got other gear that uses 18650 cylindrical cells (torches, bluetooth speakers, etc), when the battery does eventually fail, it's usually just one cell that's carked it, & you can crack the pack open & get a heap of use out of the other 5. That's why I love my older laptops - they're cheap, still run great, & I'll never buy AA's again! :-) Have fun! – user1138 Apr 16 '22 at 00:36
  • @user1138 "_And even without defying Ohm's law, mAh/Wh CAN and DO fall short of the advertised capacity, irrespective of the system load_" On a new battery with no issues? Is it possible they're rounding up when >500mAh/>.5Wh? – JW0914 Apr 16 '22 at 13:43