eeindustrial

copilot

1. Input Power Source: Typically, this will be from an existing 12V vehicle battery or alternator.
2. Charging Circuit: You need to control the charging current and voltage appropriately.
3. Battery Protection: Over-voltage, over-current, and reverse polarity protection.

1. Power Source: 12V DC (from car battery or alternator)
2. Buck Converter: To regulate the charge voltage. Your "DC 6-24V to 5V 3A CAR USB Charger Module" could partially serve for this with modifications.
3. Microcontroller/Charger IC: For intelligent charging (e.g., BQ24133)
4. Current and Voltage Sensors: To monitor the charging process.
5. Protection components: Fuses, diodes, etc.

1. Power Input
   • $V_{IN+}$: Connect the positive terminal of your 12V source.
   • $GND$: Connect the negative terminal (ground).
2. Buck Converter Connections
   • Connect $V_{IN+}$:input pin of the buck converter to $V_{IN+}$.
   • Connect $GND$:input pin of the buck converter to $GND$.
3. Charger IC Connections
   • Connect the output of the buck converter to the input pins of the charger IC (such as BQ24133).
   • The battery terminal pins of the charger IC will connect to the car battery terminals.
   • Use a current sensor between the battery and the charger IC to monitor charging current.
   • Use a voltage sensor to monitor voltage at the battery terminals.
4. Protection Features
   • Use a fuse in series with the input power to protect against over-current.
   • Use a diode to protect against reverse polarity by placing it in series with the power input.
5. Microcontroller/Control Logic
   • Optionally, use a microcontroller to provide intelligent charging algorithms and status monitoring.
   • Connect the microcontroller's ADC pins to the current and voltage sensors.

• Connect $V_{IN+}$:input pin on buck converter to $V_{IN+}$
• Connect $GND$:input pin on buck converter to $GND$
• Connect output of buck converter to corresponding input pins on the charger IC.
• Connect charger IC:BAT+ to battery positive terminal.
• Connect charger IC:BAT- ($GND$) to battery ground terminal.
• Connect a fuse in series with $V_{IN+}$.
• Connect a diode in series with $V_{IN+}$:input pin of the buck converter to protect from reverse polarity.

• Thermal Management: Ensure adequate cooling for heat dissipation.
• Charging Algorithm: Lead-acid batteries typically use a multi-stage charging algorithm (bulk, absorption, float).

eeindustrial

copilot

• Fuse: Choose a fuse rating slightly above your expected max current.
• Diode: A Schottky diode is typically used for its low forward voltage drop.

• Fuse
  • Place it in series with the positive terminal of the 12V power source.
  • Connect VIN+:1 to one side of the fuse and the other side of the fuse to the rest of the circuit.
• Diode
  • The anode connects to the output of the fuse.
  • The cathode connects to the input of the buck converter.

• Connect VIN+:1 to Fuse:Input.
• Connect Fuse:Output to Diode:Anode.
• Connect Diode:Cathode to Buck_Converter:VIN+.

• Buck Converter Module: If adjustable, set it to 14.4V to 14.7V for bulk charge.

• The input of the buck converter comes from the diode we connected:
  • Connect the diode's cathode to the input of the buck converter.
  • The output of the buck converter goes to the charger IC or battery.

• Connect Diode:Cathode to Buck_Converter:VIN+.
• Connect Buck_Converter:GND to GND.
• Connect Buck_Converter:VOUT to Charger_IC:VIN+.

• Charger IC: For managing charging, typically supporting multiple charge stages.
• Current Sense Resistor: For monitoring current.
• Voltage Divider: For monitoring voltage.

• Input Power
  • Connect the VOUT of the buck converter to the input power pins of the charger IC.
• Battery Terminal
  • Connect the battery-positive terminal to the BAT+ pin of the charger IC.
  • Connect the battery ground terminal to BAT- pin (Charger IC ground).

• Connect Buck_Converter:VOUT to Charger_IC:VIN+.
• Connect Charger_IC:BAT+ to Battery:Positive.
• Connect Charger_IC:BAT- to Battery:Ground.

• Current Sensor: To measure charge current (e.g., ACS712).
• Voltage Sensor: A simple voltage divider to scale down the battery voltage.

• Current Sensor
  • Place the current sensor in series with the BAT+ connection to the battery.
  • The output of the current sensor connects to an ADC on the microcontroller.
• Voltage Sensor
  • Use a voltage divider on the battery terminals: connect one resistor to BAT+, the second to GND, with the midpoint going to an ADC pin.

• Connect Charger_IC:BAT+ to Current_Sensor:Input.
• Connect Current_Sensor:Output to Battery:Positive.
• Connect Voltage_Divider midpoint (battery voltage downscaled) to Microcontroller:ADC1.

• Microcontroller: E.g., Arduino
• ADC Connections: To monitor sensors.

• Sensor Inputs
  • Connect the output of the current sensor to an ADC pin.
  • Connect the midpoint of the voltage divider to another ADC pin.
• Control Outputs
  • Optionally, use digital control outputs to manage the buck converter or charger IC.

• Connect Current_Sensor:Output to Microcontroller:ADC1.
• Connect Voltage_Divider midpoint to Microcontroller:ADC2.

1. Protection:
   • Connect VIN+:1 to Fuse:Input.
   • Connect Fuse:Output to Diode:Anode.
   • Connect Diode:Cathode to Buck_Converter:VIN+.
2. Buck Converter:
   • Connect Diode:Cathode to Buck_Converter:VIN+.
   • Connect Buck_Converter:GND to GND.
   • Connect Buck_Converter:VOUT to Charger_IC:VIN+.
3. Charger IC:
   • Connect Buck_Converter:VOUT to Charger_IC:VIN+.
   • Connect Charger_IC:BAT+ to Current_Sensor:Input.
   • Connect Current_Sensor:Output to Battery:Positive.
   • Connect Charger_IC:BAT- to Battery:Ground.
   • Connect Voltage_Divider midpoint (battery voltage) to Microcontroller:ADC1.
4. Microcontroller:
   • Connect Current_Sensor:Output to Microcontroller:ADC1.
   • Connect Voltage_Divider midpoint to Microcontroller:ADC2.

eeindustrial

copilot

1. Using a simple linear charger IC (e.g., LM317).
2. Using an advanced switching charger IC (e.g., BQ24133).

• LM317 Adjustable Voltage Regulator
• Power Resistors: To set the charging voltage and current.
• Capacitors: For stabilization.
• Diode: For reverse polarity protection.
• Heat Sink: For thermal management.

1. Input Protection and Regulation
   • Connect VIN+:1 to Fuse:Input and Fuse:Output to Diode:Anode.
   • Connect Diode:Cathode to LM317:VIN.
   • Connect LM317:GND to GND.
2. Voltage Setting
   • Use resistors to set the charging voltage:
     • Resistor $R_1$ between LM317:VOUT and LM317:ADJ.
     • Resistor $R_2$ between LM317:ADJ and GND.
     • The output voltage is given by $V_{OUT} = V_{REF} \left(1 + \frac{R_2}{R_1}\right) + I_{ADJ}R_2$.
3. Current Limiting
   • Use a resistor $R_{SENSE}$ between LM317:VIN and Battery:Positive to set the charging current.

• Connect VIN+:1 to Fuse:Input.
• Connect Fuse:Output to Diode:Anode.
• Connect Diode:Cathode to LM317:VIN.
• Connect LM317:GND to GND.
• Connect LM317:VOUT to Resistor:R1.
• Connect Resistor:R1 to Resistor:R2 and LM317:ADJ.
• Connect Resistor:R2 to GND.
• Connect LM317:VOUT to Battery:Positive through Resistor:$R_{SENSE}$.
• Connect Battery:Negative to GND.

• $R_1$: 2.2kΩ.
• $R_2$: 5.6kΩ.
• $R_{SENSE}$: 0.33Ω (determines current).

• BQ24133 Switching Charger IC
• Buck Converter: If not included in the IC.
• Current Sense Resistor: For accurate current monitoring.
• Passive Components: Resistors, capacitors, diodes.

1. Input Protection and Regulation
   • Connect VIN+:1 to Fuse:Input and Fuse:Output to Diode:Anode.
   • Connect Diode:Cathode to BQ24133:VIN.
   • Connect BQ24133:GND to GND.
2. Charger IC Configuration
   • Connect BQ24133: VDD to the appropriate supply voltage (typically 5-12V).
   • Use resistors to configure REGN, TS (temperature sense using NTC thermistor), and other pins as needed.
3. Battery Connection
   • Connect BQ24133:BAT+ to the positive terminal of the battery through current sensor CS+.
   • Connect BQ24133:BAT- to the negative terminal of the battery through current sensor CS-.
4. Current Monitoring
   • The CS+ and CS- pins connect through a sense resistor for current monitoring.

• Connect VIN+:1 to Fuse:Input.
• Connect Fuse:Output to Diode:Anode.
• Connect Diode:Cathode to BQ24133:VIN.
• Connect BQ24133:GND to GND.
• Connect BQ24133:BAT+ to Battery:Positive through CS+:sense resistor.
• Connect BQ24133:BAT- to Battery:Negative through CS-:sense resistor.
• Use appropriate connections for REGN, SYS, and other configuration pins as per the datasheet.

• Sense Resistor: Typically, 0.1Ω for current measurement.
• NTC Thermistor: 10kΩ for temperature sensing.

  VIN+:1 -- Fuse -- Diode -- LM317:VIN --+-- Battery:Positive
                                         |
                                   LM317:VOUT -- R1 --+
                                             |        |
                                             +-- R2 -- GND
                                   LM317:ADJ
                       Fuse:Output -- Diode:Anode
                       Diode:Cathode -- LM317:VIN
                       LM317:GND -- GND

  VIN+:1 -- Fuse -- Diode -- BQ24133:VIN ----------------------+
                       |                                      |
                 BQ24133:BAT+ -- Battery:Positive -- CS+ -- Sense Resistor
                 BQ24133:BAT- -- Battery:Negative -- CS- -- Sense Resistor
                 BQ24133:GND -- GND