How can you tell if your vehicles battery is getting weak? What are the signs of a weak battery? Should I buy a cheap battery for my car just to get by? Batteries are the heartbeat of the digital age, would you buy cheap batteries for your camera, right before going on vacation, or would you by batteries that last?
A fully charged battery in your vehicle should hold a charge for hours, even with the car doors open, the radio on and the interior lights on. One of the biggest mistakes people make when listening to the car radio while cleaning their vehicle, is to leave the key in the run position with all the instrument and warning light on, blower motor running, ac fan running and you don't even realize it. If you're going to listen to the radio while cleaning your vehicle, turn the key to accessory, not run!
A fully charged battery should last at least 30 minutes, even if the key is in the run position, but it's still not a good idea to have the key in the run position because of all the other electrical items drawing electricity from your battery. If you happen to kill your battery in this way, it is possible to have it charged back to its original state, but you definitely took some valuable hours of life from your battery. I recommend trickle charging it for at least 8 hours and then do another battery test on it to verify its OK. If you need to test your battery, it's best to load test it with a hand held tester like either of the testers show below.
or a professional series tester found at your local garage, either way, load testing it will provide you with vital information about your batteries capacity and charge level.
Why is My Battery Light On?
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 as designed.
If your battery light is on and your engine turns over, have it checked as soon as possible. The vehicles 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 checked if the warning light is on, if it's on, get it checked ASAP!
Signs of a Weak Car Battery
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.
Another symptom is if you leave your map light on overnight and your car battery is dead by morning, or if you didn't shut your door completely and the interior light (one light only, most cars today have multiple lights) drained the car battery over night. If the battery is in good condition and fully charged it should last overnight with one small light burning, if it's dead by morning, it's a sign your battery is getting weak.
Some old style automotive batteries have an indicator on the top of the battery, if the battery has a good charge, the indicator will be green, if it has a low charge, the indicator will be black. If the indicator is black, I recommend charging the battery with a battery charger, don't just have your battery jump started and hope your alternator does the job for you. I recommend charging the battery with a battery charger until the indicator changes back to green, then test the battery with a hand held battery tester like the one above or have the battery charged and tested professionally to avoid being stranded with a dead battery.
Recycle Your Car Battery
If you replace your cars battery yourself, please do not throw it in the trash, the battery acid is very harmful to the environment and to anything it touches. Batteries should be recycled, just bring it to any auto parts store or garage, and ask if they can recycle it for you.
Keeping your Batteries Charged
If you own more than one vehicle, and it happens to sit for long periods of time between rides, consider buying a battery tender. A battery tender will keep a trickle charge on the car battery while it's not in use, this will keep the battery fully charged and will extend the life of your batteries. Battery tenders are mostly used on recreational vehicles like boats, motor homes, 4 wheelers, motorcycles, etc...
My motorcycle battery was dead every spring, so I would charge it up and it would be good for the summer, the only problem, I was replacing the battery every 2 years. I never wanted to spend $40 on a battery tender but yet I would replace the battery for $80 every 2 years, was that stupid or what? I haven't replaced my motorcycle battery in over 5 years now, and I have never been stranded with a dead battery, now I have battery tenders for my boat, lawn mower and 4 wheelers as well, so keep it charged.