I am using XTAR VC4 Plus charger. Batteries (Li-ion) are brand new 1. Sofirn 14500 920 mAh & Keeppower 14500 1100 mAh with PCB & USB port. After running grading mode on this charger ( Charge, Discharge & Charge again) I am getting final readings of just over 800mAH for Sofirn 14500 (with 920 mAh Spec); & 920 mAh for the Keeppower 14500 with 1100mAH spec.
So after running the grading / mode 2 times same results. Can anyone please kindly shed light as to why I am getting these lower readings & what if there is a fix?

  • \$\begingroup\$ Keeppower states a minimum of 1000 mAh for their 14500-1100 batteries: https://www.keeppower.com.cn/products_detail.php?id=649. Your charger might just not be very accurate at measuring capacity or your battery fails the minimum requirements. \$\endgroup\$
    – StarCat
    Commented Feb 23 at 13:51
  • \$\begingroup\$ Thank you - I have 4 of the Keeppower 14500 1100 mAh batteries & 3 of the Sofirn 14500 920 mAh they all after running grading test module grading it gives consistently min 100 mAh plus lower than the manufacturers specified capacity of the battery. So I am begging to question the accuracy of the Xtar VC4 Plus charger. NB it gave accurate readings, only 50 mAh below for Ni-MH Ikea & Eneloop battery specs. \$\endgroup\$
    – AdrianH22
    Commented Feb 23 at 14:22

1 Answer 1


Both numbers may be correct.

They are just measured under different conditions.

If you don't know how exactly your device measures the capacity, and you don't know how exactly the manufacturer has measueed the capacity, they may use different conditions and end up in a different number.


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