UNSOLVED

mmaenpaa

updated

5 days ago

M

mmaenpaa

1 Rookie

7 Posts

11 Points

0

37

August 26th, 2026 16:20

Latitude 5520, 2 different laptops, *exact same* FULL CHARGE CAPACITY?

Hi, I am baffled. I have two different refurbished Latitude 5520 laptops. I have installed clean Windows 11 Pro with all the latest updates & bios updates (I believe current is 1.52 from august). However bios claims battery conditions poor & diagnostic fails on battery. powercfg / batteryreport gives exactly similar outputs. Batteries are the same but there is no way full charge can be the same on two different laptops. I suspect bios / firmware issue?

  • ejn63

    12 Elder

    31437 Posts

    155038 Points

    2

    0

    Posted August 26th, 2026 17:05

    Those serial numbers are so close together that the cells they're made from probably came from the same batch, meaning their performance will have been similar.

    And at five years old, they're due for replacement.

    You can try resetting the embedded controller (disconnect AC power and battery, hold the power button for 30 sec, and reassemble the system and re-run the powercfg command).  If nothing has changed, replace the batteries.

  • mmaenpaa

    1 Rookie

    7 Posts

    11 Points

    2

    0

    Posted August 26th, 2026 18:52

    @ejn63​ For this refurbishing company that would be bad news. As they promise >70% batteries. I will DOA them (got already one DOA accepted). By simple mathematics there is a

    0,0016 % chance that two different laptop batteries have exactly the same remaining capacity.
  • mmaenpaa

    1 Rookie

    7 Posts

    11 Points

    0

    0

    Posted August 26th, 2026 18:55

    Jus to make things more interesting I purchased third laptop (same model) from *different* refurbishing company. At least this has different readings, of course battery model is different.

  • mmaenpaa

    1 Rookie

    7 Posts

    11 Points

    3

    0

    Posted August 26th, 2026 19:01

    Each battery is coincidentally missing exactly 47,257 mWh compared to its design capacity.