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Lithium Ion Batteries

This is

By Julian Stacey

Batteries : Directory Above

A search of the web 2021-12 ref. Lithium Ion Batteries, especially for recovery of over discharged batteries, & what risks in recharging, & what charge current for 18650 cells.

External Links

Editor's own batteries:

  • Sony Energytec US18650 S STG (Blue colour)
    10 in a pack saved from a dead Compaq laptop. pairs of 2 in parallel, stored for years, @2021-11 4.08 V on each pair, except 1 pair (end of serial stack with red wire) at 2.95 V
  • Panasonic Lithium Ion CGR18650 Matsushita Electric (Pink)
    15 in a pack from Black laptop.
  • Dell From a Dell Latitude E6530 laptop gj@ later gave jhs@ 2021-11, battery labeled: 11.1V 60Wh.
    Laptop battery light gave some unusual flickering, BIOS showed zero charge even after plugged in hours.
    Drilled out the plastic rivets, squeezed the case with movable axle pliers, to stress the glue join along the case, finger nail at corner, 2 screwdrivers alternately working along to crck the case shell apart.
    6 orange colour cells, Cells in pairs of 2 parallel wired, 3 pairs in series.
    Cells labeled LG ABC21865 L332K276A2,
    2 thin wires: 1 green (@ 4V), 1 yellow (@ 8V), 1 red thick wire (@ 12V) going back from each pair of cells voltage stage to PCB controller of battery pack. + 2 thin black wires adjacent, probably a temp detector. Battery PCB marked Dell MaCallan
    Cell voltages (- end) 0.922 V , 1.035 V , 0.906 V (+ end)
    Recharging: I used 50 mA into all 3 in series, within minutes they each went to 2.4 Volts
    0:00 2.40 V  
    1:30 3.08 V  
    2:00 3.13 V  
    2:30 3.25 V  
    4:00 3.46 V 1.8 ohms
    4:45 3.57 V  
    5:15 3.57 V  
    5:30 3.57 V  
    6:15 3.62 V  
    7:00 3.64 V 2.27 ohms
    8:00 3.58 V 0.56 ohms
    8:02 3.57 V 0.33 ohms
    9:00 3.58 V 0.33 ohms
    10:30 3.61 V 0.33 ohms
    11:00 3.62 V 0.39 ohms
    13:00 3.67 V 0.33 ohms
    HH:MM v.vv V _.__ ohms
    Internal Resistance = V-on-charge = V-open-circuit / 50mA charge current / 3 (cells in series)

    Later when higher voltage, I will return it to standard charging on laptop, then as it may have lost capacity, I may do a discharge test, & or swap the cells for Sony cells

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