Follow general precautions:

•Always wear proper eye, face and hand protection.
•Always charge batteries in a well-ventilated area.
•Keep vents tight and level.
•Turn the charger and timer “OFF” before connecting the leads to the battery to avoid dangerous sparks.
•Never try to charge a visibly damaged or frozen battery.
•Connect the charger leads to the battery; red positive (+) lead to the positive (+) terminal and black negative (-) lead to the negative (-) terminal. If the battery is still in the vehicle, connect the negative lead to the engine block to serve as a ground. Be sure the ignition and all electrical accessories are turned off. (If the vehicle has a positive ground, connect the positive lead to the engine block.)
•Make sure that the charger leads to the battery are not broken, frayed or loose. Never attempt to charge a battery if you are unsure. Make sure you switch the engine off and get in touch with us.