Editing Battery Refurbishment (section)

=== Spotting fake and reclaimed cells ===

The market for cylindrical lithium cells is full of counterfeits, and a rebuilt pack is only as good as the cells in it.

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Warning signs when buying cells'''<ref name="fake">Counterfeit-cell identification guidance from the lithium cell reseller and battery-building community, summarised across sources including [https://cellsaviors.com/ Cell Saviors] and specialist retailers. The genuine-capacity ceiling of roughly 3500 mAh for an 18650, the 42–50 g weight of a genuine high-capacity cell, and the print-quality and terminal-condition indicators are the consistently reported markers.</ref>
! Sign !! What it means
|-
| Claimed capacity above about 3500 mAh in an 18650 || '''Fake.''' Genuine 18650 cells run roughly 2000–3500 mAh. "6000 mAh" and "9900 mAh" 18650s do not exist.
|-
| Cell weighs 30–35 g || '''Fake or grossly under-filled.''' A genuine high-capacity 18650 weighs about 42–50 g. A kitchen scale is the cheapest counterfeit detector there is.
|-
| Misspelled brand names, misaligned logos, blurred printing || Counterfeit wrapper.
|-
| Scratches, dents, rust, burn marks or weld scars on the terminals || A reclaimed cell pulled from a scrap pack and re-wrapped, sold as new.
|-
| No manufacturer datasheet exists for the part number || Treat the ratings as fiction.
|-
| Price far below the going rate for a known brand || Cells from Samsung, LG, Panasonic/Sanyo, Molicel and Murata cost what they cost.
|}

The only proof is measurement: charge the cell, run a capacity test, and compare against the claim.