Using a multimeter (set to DC Volts, 20V range), measure between:
| Measurement Points | Expected Voltage (Standalone) | Expected Voltage (In Laptop, AC Present) | |----------------------|-------------------------------|-------------------------------------------| | Pin 6 to Pin 1 | 0V (FETs open) or 10.8–12.6V (rare if not locked) | 11–13V (charging) / 9–12V (discharging) | | Pin 3 (SMBC) to GND | 0V (no pull-up) | 3.3V | | Pin 4 (SMBD) to GND | 0V | 3.3V fluctuating (data activity) | | Pin 5 (TH) to GND | 10 kΩ to 100 kΩ (resistance) | 0.5V–2.5V (depending on temperature) |
Warning: Do not short Pin 6/7 to Pin 1/2 when the battery is not connected to the laptop. The protection circuit may permanently blow an internal fuse (often a 10A–15A SMD fuse).
| Parameter | Min | Typ | Max | Unit | | :--- | :--- | :--- | :--- | :--- | | P+ to P- voltage (operating) | 9.0 | 11.55 | 12.6 | V | | P+ to P- voltage (protection trip) | 4.2 (per cell under) | – | 4.35 (per cell over) | V | | SMBus logic low (VIL) | – | – | 0.8 | V | | SMBus logic high (VIH) | 2.1 | 3.3 | 3.6 | V | | SMBus clock frequency | – | 100 | 400 | kHz | | PRES pin impedance (active) | – | 10 | 50 | Ω to GND |
Before diving into the pinout, let’s establish the technical specifications of the MU06 battery: