AUTOOL OBD II Memory Saver Cable 12V — Digital Voltage & Current Display, 3A Fuse and Anti‑reverse Protection

If you need to change a 12V car battery without losing on-board memory or want a simple way to detect electrical leakage, this compact OBD II memory saver supplies emergency ECU power while showing live voltage and current. It plugs into the vehicle OBD port and uses an external 12V DC source—like a spare battery or running starter—to maintain settings and monitor current draw. The unit includes a 3A fuse for overload protection and anti-reverse connection safeguards to prevent damage from incorrect hookups.

How does this cable preserve ECU memory during battery swaps?

When the car’s main battery must be disconnected, the AUTOOL cable supplies continuous 12V power through the OBD port so the vehicle’s ECU and other modules don’t lose learned settings or radio codes. This avoids reprogramming sequences and preserves stored faults and calibration data.

• Uses any 12V DC source (spare battery, running starter, or power outlet).
• Plugs into the vehicle OBD II port for a direct ECU feed.
• Built-in 3A fuse provides overload protection during swaps.
• Anti-reverse design prevents powering if connected backward.

Can this device help find battery drain or electrical leaks?

Yes—the integrated digital display shows voltage (red) and current (blue), so you can monitor changes as you remove fuses. By unplugging fuses one at a time and watching for current drops, you can isolate which circuit is drawing abnormal current and trace the offending component.

• Live voltage and current readout for precise measurements.
• Works by comparing current before and after removing fuses to locate leakage.
• Useful for tracking parasitic drains caused by accessories or faulty modules.
• Requires main battery disconnected for load to be drawn from the external source.

What safety features and warnings should I follow when using it?

The AUTOOL memory saver includes a replaceable 3A fuse and anti-reverse connection protection to reduce risk during use. The display flashes and warns if abnormal voltage or current is detected. Always ensure the vehicle power is off during battery replacement and avoid performing other electrical work while the external source is connected to prevent sudden current spikes.

• 3A fuse protects against overloads; replace if blown.
• Digital alerts for abnormal voltage/current conditions.
• Anti-reverse clamp prevents powering when hooked up incorrectly.
• Disconnect vehicle main battery and avoid other electrical operations during swap.

How do I set it up with a spare battery or starter?

Connect the memory saver’s alligator clips or fused lead to a 12V DC source, then plug the OBD connector into your vehicle. Confirm the digital readout shows expected voltage and that current flows when the vehicle’s main battery is removed. If the main battery remains connected and charged, no current will flow from the external source, so removal is necessary for proper operation.

• Attach clips to the spare 12V battery (observe polarity).
• Insert OBD II plug into vehicle connector to feed ECU power.
• Verify voltage/current on the display before starting replacement.
• Ensure main battery is disconnected to allow load from the BT30 circuit.

Who is this for: The AUTOOL OBD II Memory Saver is designed for professional mechanics, DIY enthusiasts, and fleet technicians who regularly replace batteries, troubleshoot parasitic drains, or want to protect vehicle settings during maintenance. It's practical for anyone who needs a compact, easy-to-read tool to maintain ECU data and quickly locate electrical leaks without bulky equipment.