A car battery is something that doesn't last forever. There will come a point where the battery needs to be replaced with a new one, simply due to the old battery reaching an old age or from being used too much. Here are a few key signs that your car battery needs replacement. 

Engine Cranking Problems

Pay attention to how your car responds to turning it on.  A notable sign that you have a problem with your battery is that the car will be really slow to start up when turning the key. This is not good because the vehicle isn't getting the power that it needs as the engine is cranking.  As long as you know that you didn't leave the lights on in your car the previous night, then the battery is likely on its last legs and needs to be replaced or you could end up in a situation where you're stranded and unable to start your car. 

Headlight And Electrical Problems

You likely know better than anyone how bright your headlights and interior lights are when you use them. If it looks like the lights are a bit dim, then they are not getting the power they need from the battery. Electrical issues can also be apparent when the device receiving electricity is weak. You may even find that the strength of your horn is different, such as not being as loud as it was in the past.

Emergency Jump Problems

Does your vehicle work fine after getting an emergency jump but then intermittently run into problems later where you need another jump start? While this could be a problem with the alternator not charging the battery, it is possible that the battery is simply unable to hold its charge like it did when it was new. You may get a few more starts out of it, but you'll eventually need a jump start or battery replacement to get things going again. 

Odd Odors

A bad battery can also cause problems with odd odors coming from under the hood. It's a problem that does not come from a weak battery that doesn't hold a charge but from a battery that is overcharging and actually releasing fumes and sulfuric acid. This is not just a problem that requires a new battery but is quite dangerous as well. 

Age Issues

When in doubt about the age of the battery, take a look at the printed information on the casing to see how old it is. A Car battery can last 3–5 years before it needs replacement, but extreme heat can cause more wear and tear and lower the lifespan to the low end of that range. 

Contact a professional for more information about car batteries.