Check the battery by visually examining the acid bulb located on the top of it and determine how much electrolyte. To test using a hydrometer, measure the specific graveness of the electrolyte. Use a digital voltmeter to perform open circuit voltage testing. If it has less than what is specified, charge it first before you proceed. To determine its capacity to run amperage draw heavy devices such as starter and accessories, use a Battery Load Tester. Check for constant drains on electrical system by doing a battery drain test. Before removing a battery, start with a negative cable then disconnect the positive one; remove battery hold-down clamp and lift out battery; check if there is corrosion in the battery tray and clean if necessary. After that, when fixing batteries ensure that you align the notch at center with hole for holding down clamp and then you screw tightly with bolt. Unplug PCM and remove liner (if equipped) from tray used in retaining batteries after which take off all mounting bolts attaching tray itself to vehicle's frame; reverse procedure for installation.