Batteries Starter and alterators
Automotive batteries have a finite life span. Undercharging, overcharging and heat all team up to degrade your battery. Poor electrical connections make it more difficult for even a good battery to do its job.
If the battery shows less voltage or won’t take a charge, it’s time to get out the hydrometer. This device checks the proportions of sulfuric acid and water in the electrolyte, which is a precise indication of the level of charge. Pull up the battery fill caps–if you can. Add distilled water to any cells in which the level of electrolyte isn’t touching the bottom of the fill port. Use only distilled water. The minerals in tap water will eventually reduce a battery’s capacity.