Check the battery type (lead-acid wet cell, AGM, or gel) and match the charger settings accordingly
Verify the charger is compatible with the battery voltage (typically 12V) and battery capacity (Ah)
Wear eye protection and gloves
Work in a well-ventilated area away from flames, sparks, and smoking
Turn off the vehicle and all accessories (lights, radio, HVAC)
If charging in the vehicle, set the parking brake and keep the engine off
Identify the battery terminals: positive (+) and negative (–)
Inspect cables and terminals for damage, corrosion, or loose connections; clean corrosion if needed
If using a battery charger with ring clamps, ensure clamps are secure and not touching each other
Connect the charger positive (red) clamp to the battery positive (+) terminal
Connect the charger negative (black) clamp to the battery negative (–) terminal
If instructed by the charger manufacturer, connect the negative clamp to a grounded metal point on the vehicle instead of the negative terminal (only when specified)
Plug in the charger to a properly grounded outlet
Set the charger mode and current/voltage settings (or select “battery type” and “start/charge” as directed)
For manual chargers, start with a low charge rate if unsure, then adjust within the recommended range
Monitor charging progress (especially if not using an automatic/maintaining charger)
Stop charging if the battery becomes excessively hot, emits heavy fumes, or shows swelling/leaking
When charging is complete, unplug the charger from the outlet
Disconnect clamps in reverse order: remove the negative (black) clamp first, then the positive (red) clamp
If you removed the battery, reinstall it securely and reconnect terminals in the correct order (positive first, then negative), tightening clamps firmly
Check battery voltage with a multimeter if available
Dispose of any old batteries properly at a recycling facility