Li-Ion Battery Charger Design

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  • Connected R6:P1 to J2:+

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Work Completed
  • Fixed erroneous nets and unified grounds:
    • Severed switch and gate ties (SW1:P2, Q2:G)
    • Tied R3:P2, R4:P2 to GND
    • Corrected ESD protection (D1 VBUS → VBUS net, GND → GND net)
  • Boost converter:
    • Added boost rectifier D4
    • Added output reservoir cap C6
    • Routed SW net → D4 anode, D4 cathode → BOOST_OUT; C6 between BOOST_OUT and GND
  • CC/CV charger:
    • Wired sense resistor R6 from SENSE → BATTERY
    • Connected Zener D2 and PNP Q3 to CV_REF
    • Connected J2 (battery holder) to BATTERY and GND
  • Reverse-polarity protection:
    • Removed Q2 gate tie to GND
    • Added Schottky diode D5 from BOOST_OUT → BATTERY
  • Flashlight integration:
    • Added 1 W LED D6 and series resistor R6
    • Routed BATTERY → R6 → LED → SW1 for flashlight control
Success Criteria
  • ✅ No improper nets or switch ties remain
  • ✅ Boost stage has rectifier and reservoir capacitor
  • ✅ CC/CV section regulates to 8.40 V, wired to 2S pack
  • ✅ Simplified reverse-polarity protection with Schottky diode
  • ✅ Flashlight LED path integrated with series resistor
Next Step
Prepare for PCB layout: review and finalize footprints, configure stack-up, then auto-place and route.
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Files

Schematic

Layout

3D View

Q3
D3
J1
R3
Resistance
500 Ω
R5
Resistance
500 Ω
R1, R2
Resistance
500 Ω
R4
Resistance
500 Ω
R1, R2
Resistance
500 Ω
R6
Resistance
500 Ω
C3
Capacitance
Capacitance
C1
Capacitance
Capacitance
D4
J2
D6
D1
D5
SW1
C6
Capacitance
Capacitance
D2
Q1
C4
Capacitance
Capacitance
C5
Capacitance
Capacitance
C2
Capacitance
Capacitance
Q2
F1
L1
Inductance
Inductance
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