Battery connected... but not being recognized

I have a 5V boost regulator (TPS61030 - 5V/2A output) circuit connected to the Li+ of the Electron. All functions normal under light current loads. When I pull more than 100mA from the 5V regulator, the Electron battery appears to become electronically disconnected.

How can the battery - if plugged into the JST connector - no longer be functioning?


Observations (Malfunctioning State):

  • PMIC responds to all I2C commands (no faults)
  • Fuel gauge (0.15V and 0% state of charge)
  • Battery is charged :slight_smile:
  • Multiple batteries were tested (none are recognized)
  • No parts are getting hot
  • Reproducible on two Electrons
  • I can’t see on the schematics how a direct connection from BAT to Li+ could be broken?!?

Symptoms (Malfunctioning state):

  • USB disconnected - Battery connected:
    - no voltage on Li+
    - Electron not running (no LED or anything)

  • USB connected - Battery connected:
    - all internal Electron functions are normal (5V regulator not working of course)
    - PMIC has no fault status
    - PMIC charging status LED on (not blinking)
    - PMIC charging status LED stays on (not blinking), even when battery removed

Checked the circuit - TSP61030 5V regulator chip was dead. Replaced with a new TSP61030 = all functions back to normal operating conditions.

Question:

The goal is to provide 3.3V (from Electron) and 5V outputs (from 5V boost regulator) from the LiPo battery.

Is it safe to use a 5V boost regulator circuit connected to the Li+ pin?