The surface charge must be removed to accurately measure the voltage of the battery. You can do this by turning on the high beams for ten seconds, turning them off and letting the vehicle stand for two minutes. Then, remove the battery from the vehicle. Visually inspect the indicator eye on top of the battery to check its state of charge. If it is clear, then charge the battery. A digital voltmeter can be used in this kind of test, which is an open-voltage circuit test. With engine and all accessories off, connect negative probe of voltmeter to negative terminal of battery and positive probe to positive terminal. For a battery voltage of 12.6 volts or more, it should have enough power; otherwise means that it has to be charged before it is put into use. After that you will need to perform a battery load test with a load tester. It determines whether or not a battery has enough capacity to start a car's as well as operate other electronic parts when high electric current is required from a storage device for a short period only. The tool will show if there is anything wrong with it immediately, if the condition of your battery is weak or defective. Take off cable from negative terminal and then from positive terminal in order to replace the battery. Remove both hold-down clamp first and later on take out the battery itself too. Visually inspect tray, retainer brackets and related fasteners for corrosion or damage. In cases where corrosion exists present you should clean it up using baking soda/water solution and repaint as required in that area only. You should also clean as well as service your battery and cables whenever necessary Ensure that when buying another one just like your old one in terms of dimensions, amperage rating , cold cranking amps rating Before fixing make sure that your new cell gets fully charged To install new batteries first connect positive cable while you are supposed to attach lastly negative one. At last apply a light coat of the battery terminal corrosion inhibitor to prevent the buildup of corrosion on the connections.