A vehicle's battery is one of the most important components to any vehicle. It is responsible for starting the engine, and without it, the vehicle cannot start. Throughout their service life batteries are subject to constant cycles of charging and discharging, as well as high heat conditions from the engine bay where they are most commonly installed. Since they serve the important purpose of getting the engine started, when they do fail, they can leave the vehicle stranded and cause a big inconvenience for the driver,
   So how can you tell your vehicles battery is getting weak? The most common symptom is a slow engine crank, when you start to hear the engine in your car crank slowly, have the battery checked right away. The engine draws a lot of amperage from the battery during start up, that's why the slow crank is the most common symptom.
Rack of batteries
battery test
car test equipment
   Because the alternator plays such a vital role in keeping all of the vehicle electrical components powered, any problems with the alternator can quickly develop into problems with another system or component on the vehicle. Usually, a defective or failing alternator will produce a few symptoms that can alert the driver of a potential issue, allowing time for the driver to service the vehicle before a bigger problem occurs.

#1 Hard or slow cranking, more noticeable with cold weather and first start of the day.  It is the job of the battery to provide the power to crank the engine and start the vehicle, however, it is the job of the alternator to make sure that the battery stays charged. If the alternator is beginning to have problems or has failed, it will not be able to meet the vehicle’s electrical needs, including keeping the battery fully charged. A low or uncharged battery will not be able to keep up with the load required to start an engine multiple times, and will result in a no start condition requireing imediate service.

#2 Dim or flickering lights. If you notice any sort of flickering or dimming of the lights when operating the vehicle, it may be a sign that the alternator is not generating enough power to keep up with the vehicle’s electrical needs. The dimming or flickering may coincide with certain actions when operating the vehicle, such as dimming when pressing on the brake pedal, turning on the stereo, wiper, heater or rear defrost. This may indicate an alternator that is unable to keep up with the needs of the vehicle electrical system while it is running, and when additional loads are placed on it.


   The electrical charging system is one of the most important systems on any vehicle. The charging system is made up of several components, including the alternator and battery, that work together to supply all of the vehicle electrical needs. The alternator is what specifically generates the amperage and voltage required to meet the vehicle electrical needs, including keeping the battery charged.

   I'm not sure why car manufactures put a battery warning light on the dash, it will never illuminate when your battery is dying or even when your battery is dead, the battery light is for the alternator, not the battery. If your battery light comes on, it's because your alternator is either over charging, under charging, or not charging at all. There are several components that could make the battery warning light come on, for example; the ELD, (electrical load detector) voltage regulator, a blown fuse, or a bad wire harness, but it still leads to the alternator not charging normally.

   If your battery light is on and your engine turns over, have it checked out immediately. The vehicle battery will hold a charge for a while, but not forever, especially if you're using the radio, heater, wipers and head lights, this will drain the battery quick and leave you stranded, so don't wait to have the battery warning light checked out, if its on, get it checked right away

alternator test
starter test
   Your starter can give you the same hard or slow cranking condition as the battery, more likely when the vehicle is hot.
   Bad wiring connections or loose starter bolts can cause intermittant hard or no crank.
  Clicking can be battery bad, or weak caused by alternator not charging, wiring, loose bolts or faulty starter.