Topdon V1500 Manuel D'utilisation page 12

Step 2:
Connect the battery clamps to the vehicle battery.
Red clamp to the Positive Polarity (+), Black clamp to
Negative Polarity (-). The green illumination of the Tool
Ready indicator shows that the jump starter is ready for
jump-starting.
Just by connecting the clamps to the terminals
correctly, the V1500 delivers a jump to the vehicle
battery.
Step 3:
Try starting the vehicle. If it fails, disconnect the
battery clamps from the vehicle's battery and wait
for 20 seconds, then reconnect and try again. It's
recommended not to attempt more than 3 consecutive
jump starts within 2 minutes.
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