Can You Run a PSP Without a Battery? Technically Yes, But Not Recommended

Short answer: The PSP requires a battery to boot. Even with the AC adapter plugged in, the system checks for a battery presence and charge state before powering on.

Why the Battery Is Mandatory

• Power management IC expects battery as primary source; AC adapter charges battery, battery powers system.
• Voltage regulation: Battery smooths current spikes (UMD motor, Wi-Fi, backlight).
• Firmware check: Bootloader verifies battery communication (SMBus/I2C). No battery = no boot.

"But I've Seen It Work Without Battery!"

Two scenarios where it might appear to work:

1. Dead-but-present battery: A swollen/failed battery still communicates ID/resistance, letting the PSP boot on AC power alone. Risky—swollen cells can vent/fire.
2. Hardware mod (Pandora/LED battery pin short): Bridging specific pins on the battery connector can trick the PMIC. Advanced soldering required; kills battery charging circuit permanently.

Practical Advice

• Buy a replacement battery: $10–20 for generic 1200/2200 mAh (PSP-1000/2000/3000/Go use different sizes).
• If battery is swollen: Remove immediately. Do not charge. Recycle safely.
• AC-only "desktop" use: Keep a healthy battery installed; it will bypass charging once full.
• PSP Go: Internal battery—non-user-replaceable without opening case. Same rules apply.

Myth Busting

• ❌ "AC adapter powers PSP directly" – False.
• ❌ "Battery only for portability" – False; it's part of the power topology.
• ✅ "Dead battery kills portability only" – True, if it still communicates.

Just buy a $15 battery. It's safer, preserves the hardware, and keeps the clock/date working.