Editing Battery Refurbishment (section)

=== Chemistry ===

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''The four chemistries found in vintage computer and handheld packs'''
! Chemistry !! Nominal !! Fully charged !! Discharged !! Typical era and use !! Notes for the rebuilder
|-
| '''NiCd''' (nickel-cadmium) || 1.2 V/cell || ~1.45 V || 1.0 V || Late 1970s–early 1990s laptops, portables, calculators, RTC backup || Tolerant, but cadmium is toxic and NiCd packs leak corrosive electrolyte as they age. Pre-tabbed cells are still made.
|-
| '''NiMH''' (nickel-metal hydride) || 1.2 V/cell || ~1.45 V || 1.0 V || Early–mid 1990s onwards; the usual NiCd replacement || Higher capacity than NiCd in the same can. Same nominal voltage, so it is often a drop-in.
|-
| '''Li-ion''' (cylindrical) || 3.6–3.7 V/cell || 4.20 V || 2.50–3.00 V || Mid 1990s onwards; laptops, camcorders || Never soldered. Requires protection electronics.
|-
| '''LiPo''' (lithium-polymer pouch) || 3.7 V/cell || 4.20 V || 3.00 V || Late 1990s onwards; PDAs, organisers, thin handhelds || Soft foil pouch. Extremely easy to puncture. Never soldered at the cell; the tabs are the only place an iron may go, and even then reluctantly.
|}

Chemistry is normally printed on the pack label, on the cell wrapper, or moulded into the casing. If the label is gone, cell count against pack voltage is decisive: a 1.2 V nominal cell only ever produces multiples of 1.2 V (2.4, 3.6, 4.8, 6.0, 7.2, 9.6, 12 V), while lithium packs come out at multiples of 3.6 or 3.7 V (3.6, 7.2, 10.8, 11.1, 14.4, 14.8 V).