The Battery Box or Platform should be checked for acid corrosion. Neutralize corrosion with baking soda and water. Battery strength, cables and electrolyte fluid should be checked. A voltmeter reading should not show below 7 volts. Cables should be replaced if very rusty or corroded.
Batteries emit explosive gases.
Never smoke or light a match when working near a battery. Wear safety glasses. A vehicle's engine generates enough heat to destroy itself. The cooling system protects against damage, keeping the engine operating within the correct temperature range. Surveys among auto mechanics indicate the cooling system is among the most neglected aspects of car care.