How Long Will a Battery Last With a Bad Alternator

by Phil Borges // in Car

If you’re driving a car with a bad alternator, it’s important to know how long your battery will last. If the alternator is not functioning correctly, your battery will be drained much quicker than if it was in good condition. In order to figure out how long your battery will last, there are some factors that need to be considered.

You know that your car will eventually stop if the battery is constantly being drained. The time it takes to get there depends on how often you drive, but a dead alternator can lead to an early death for your vehicle and leave you stranded in no-mans land.

Your ignition system relies heavily on both the battery and alternator so everything works smoothly while driving down the road. It has been seen where batteries are not recharged as they should be because of poor quality or old age; this results in longer periods between charges which causes vehicles with weak batteries cannot continue running without stopping due to their charge draining away too quickly. This becomes even more problematic when considering cars whose engines rely solely on electrical power during times of low-speed operation such as in traffic, or at stoplights.

There are many factors affecting how long a battery will last when the alternator isn’t charging it. The type of engine, how modern the car is, and even if you’re driving in daylight or at night can have an effect on your battery’s charge–and so does its age! If you need to use headlights during dark weather conditions then that’ll take a toll on your vehicle’s power supply too. Below is two vehicle types that may help you:

Classic Diesel Cars

Older diesel cars are very interesting and a lot different from newer models. The engine is usually the main power source, but it also drives some smaller gadgets like the fuel pump or hydraulic pumps for things such as steering fluid – all without electricity! This makes them completely portable once started, which can be handy in an emergency situation where there might not be any other sources of energy nearby to use.

The battery that comes with these older engines will last you several hours on its own before needing recharging, so they’re perfect if you know your car won’t have access to electric sockets outside of emergencies; however, this does mean that when using one at home (or anywhere else) while plugged into mains power then yes-the batteries will charge up.

Gas-Powered Cars

In a gas-powered car, the engine is controlled by electronic systems. Unlike diesel, it has spark plugs that will be a large drain on the battery. The next big draw of power might come from the Engine management system and airbag systems. With all this going on, your average battery could last as little as 30 minutes or up to two hours if you’re lucky! If you have to start the car without an alternator (i.e., in case there’s no electric current), don’t turn off once things get started because the battery is quickly drained.

Bad Alternator vs Bad Battery

A bad alternator is when the alternator goes bad, and your battery will be drained much faster than if it was in good condition. A bad battery may mean that your battery isn’t holding a charge or dying much quicker than it should. Below are some signs of a bad battery:

Signs of a Bad Battery

  • When the battery is low, it may take a lot of tries to start the car. If you just hear a click instead of turning it on, try charging your battery so it can function properly.
  • If the battery is not charging, there are several things that might be wrong:
  • Corroded posts. Corroded posts are a cause for alarm, as they could lead to problems in the long run. Some signs of corrosion include loose connectors and wear on metal surfaces. Use a wrench or pliers to disconnect your battery cables before you can clean up any post residue that may be present; this is not only easier but also ensures that all connections will be properly tightened when finished! After locating corroded areas, use an inexpensive wire brush with medium-grit sandpaper wrapped around it (or simply rub vigorously) until shiny again – never touch bare metal because it WILL leave black marks which require extensive hand washing after removal! Finally, reconnect the wires securely and make sure everything’s tight by tightening them down — pay special attention however if there were multiple instances of corrosion as it’s possible that the posts may need to be replaced
  • The battery not holding charge. If you have a two to five-year-old battery, it may not be working as efficiently. There are many factors affecting the life of a car’s batteries such as how frequently they are used and their age too- especially for those that get repeated cycles from being in use to sitting idle then back again! One way to test your charger (or alternator) is by unplugging your vehicle’s electrical system altogether but still, try starting with just the key barrel engaged followed by running on the electric starter until it stalls out three times consecutively without any power at all going to anything else than through this technique alone; if there has been no improvement after doing so replace both parts before proceeding.

Signs of a Bad Alternator

All cars have a light on the dashboard that indicates if there is any electrical problem. One of the most common reasons for this warning signal coming back on again and again, which often leads to an alternator replacement, is because your car battery has gone dead due to lack of use or from leaving it in storage over time.

There are many indications that your alternator is not working correctly:

  • When your car starts without a hitch but the check engine light flashes on, it is most likely because of the alternator. This device maintains power to all electrical components in your vehicle and generates electricity for charging purposes when needed. The electric charge from this battery-like dynamo powers up headlights, radios, windshield wipers – everything that makes driving possible at night or during bad weather conditions!
  • Modern cars are equipped with a variety of features that can be activated to save power, such as shutting down air conditioning and anti-lock brakes when not in use. If your vehicle does this while the warning light is on you should suspect an alternator problem.
  • If your car’s alternator is not working properly, the headlights may get very dim at night.
  • Anything odd with the electrical system such as a battery light coming on and off or headlights flickering.

What Causes an Alternator to Go Bad

The alternator is a simple part of any car; it’s just a matter of time before the parts start to wear out. If you want your engine running smoothly, then don’t let dirt or dust build upon this important component! Below are common causes of a failing alternator:

  • If you’re experiencing a strange whirring noise while turning your engine on, it might be time to check the belt tension. In order for an alternator bearing not to wear out too quickly, make sure that the drive belt is tightened enough so there’s no slack in between when rotating.
  • Dirt, dust, and oil in the electrical windings can clog up crucial parts of an alternator which will cause it to lose efficiency.

5 Tips For Longer Driving With A Bad Alternator

  • Make sure you have the correct spark plugs in your car; this is crucial! If you notice that it takes a while to start your engine, or if it starts to speed up when you put your foot on the gas, it’s time to change those spark plugs!
  • Your car may also be running poorly because of a burned-out spark plug. If the problem persists, don’t wait for the warning light – replace them with new ones as soon as possible.
  • Replace your air filters regularly. Air filters regulate airflow into your vehicle so making sure they’re clean can potentially avoid a number of problems with other parts of the engine.
  • The battery not being charged is a common issue with an alternator. If you notice that your lights are dimming or flickering, it’s time to have the battery checked.
  • Make sure you don’t let the battery run out completely; this will help to avoid any future problems with your alternator or starter.

Can a bad alternator kill a new battery?

Yes, bad alternator kill battery with a process called sulfation. Sulfidation is the build-up of lead sulfate crystals on cell plates and grids, which occurs when the battery isn’t receiving enough charge. Sulfation is nearly impossible to stop once it reaches this point, but you can prevent it before it starts by keeping your charging system in good working order (such as a bad alternator). Also be sure not to overcharge or undercharge your battery using an underperformed alternator if one of these symptoms exist: lack of power surges while starting engine from the dead, slow cranking speeds like below 8 seconds after car was driven just 15 minutes ago; and/or for more than 10 seconds below 10.5 volts when the engine is running.

How much does it cost to fix an alternator?

The cost of repairing an alternator depends on the model and make of a car and where the problem originates. In general, though, an alternator can be replaced by a DIY instead of taking it to shop for repair. Often times this is because the part itself can be very expensive, upwards of $300 or more. An alternator could also interfere with other parts in your car when it’s not working properly so you have to take it into a mechanic every time there is an issue. An average price for replacing an alternator should typically be cheaper if done at home, but only if it’s being installed in a vehicle that uses jumper cables so that the battery can provide power to keep your radio on while you’re doing the job.

How long does it take to fix the alternator?

It depends on your skill level, what type of car you have and how proactive your owner’s manual is. The actual mechanics that go into fixing the alternator take about 10-15 minutes. However, if you don’t know where to look or are going in blind you can spend hours trying to figure it out. Better yet, call a technician who will do all the work for you!

How long does it take for a bad alternator to drain a battery?

It really depends on how bad the alternator is – if it’s completely shot, then it can drain a battery very quickly. If it’s only somewhat damaged, then it might take a little longer. Ultimately, though, if your alternator is going bad, it’s not going to be good for your battery (or your car). So, if you think there might be an issue with your alternator, get it checked out as soon as possible.

How long does the alternator last?

The life of a car’s alternator varies depending on driving conditions, things like how often the vehicle is driven or parked, and what kind of charger is used to maintain battery charge. The average alternator life for small engines is between 80-120k miles. Different factors such as what type of oil was used early in its lifetime, overcharging or undercharging with headlights and chargers which may throw off the voltage will all have a factor in determining when an alternator needs to be replaced. A new battery can also affect how long an alternator lasts by causing it to wear out quickly as well as if corrosion has occurred in the past that might cause them not to last very long after installation.

If you carry on driving your car with a bad alternator, you will have to charge your battery regularly. For the health of your battery and car, replace the alternator as soon as possible once it has failed. Ez Battery Reconditioning is a course on how to recondition that dead battery, that way you’ll never have to pay for a car battery again click the link below to learn more.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.