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Will My Car Battery Recharge Itself?
A car battery is a lot like any other battery in that it needs an external power source to be recharged. While there is wireless charging available for cell phones, self-recharging battery technology is not something that has been invented yet. So with that said, can a car battery recharge itself?
No, a car battery does not have the ability to recharge itself. Car batteries need to have an external power source such as an alternator or battery maintainer to keep the battery charged up.
But can car batteries be recharged without a jump, or do you first need to recharge the battery? Can a completely dead battery be recharged? What’s the best way to charge a car battery without damaging it? Keep reading to find out.
Can A Car Battery Recharge Itself Overnight?
A car battery needs a power source to charge it. Normally the car’s alternator will charge the car battery while the car is running but if the car is not running overnight the alternator won’t be able to provide electricity to the car battery.
The only way to charge a car battery overnight with the car not running is via a trickle charger or external battery charger/maintainer.
To charge a car battery overnight a trickle charger would need to be hooked up to the car battery and be hooked up to a wall outlet to be able to provide electricity to the trickle charger and to the car battery.
Will A Car Battery Recharge Itself Without a Jump?
A car battery won’t be able to recharge without the engine running and the alternator providing power to the car battery. Typically when you need to jump a car battery the battery charge has been depleted so much that it can no longer provide enough energy to start the car.
This could be from a multitude of things but usually, it’s because the car battery is old and is no longer able to properly hold a charge or the alternator is failing and is not able to provide enough energy to the car battery to keep it fully charged.
If you are interested in learning what the symptoms are of a failing alternator check out my article. You may also want to know how much it would cost to replace an alternator if yours is bad. If so check out my other article about how much it cost to replace an alternator.
Can A Completely Dead Battery Be Recharged?
Yes, a dead battery can be recharged provided that the battery cells inside the battery aren’t damaged. As long as the battery cells can still hold a charge an alternator or trickle charger would be able to recharge the battery to a fully charged state after a couple of hours.
Alternators aren’t designed to charge your car’s battery if it’s been fully discharged, they are only designed to keep your car battery charge topped off. If your car’s battery has been fully discharged it’s best to charge your car battery using a battery maintainer. 
How Can You Keep Your Battery From Dying?
The best way to keep your car battery from fully discharging is by allowing the alternator enough time to charge the battery. Every time you start your car it drains some of the stored energy from your car battery. If you make a lot of short trips your alternator won’t have enough time to charge your car battery to a full charge.
Obviously you should also be careful to not keep anything on that could drain the battery while the car is off. This includes things like your headlights, car radio, and HVAC. If your car allows you to charge electronic devices while the engine is not running this can also drain your car battery.
How Long Should A Car Battery Last?
A car battery is designed to last around 5 years give or take from when the battery was originally manufactured. Some car batteries may last longer than 5 years while some may last less than 5 years.
The amount of time that the car battery set on the shelf will also impact how long the car battery will last as the 5-year window starts from when the car battery was manufactured not when you first put it in your car.
Do You Need To Replace Your Car Battery?
To learn more about how to test a car battery to see if it is going bad and the costs associated with replacing a car battery check out my other article how much does it cost to replace a car battery?
How Can You Preserve the Life Of Your Car Battery?
The best way to preserve the life of your car battery is to keep the battery fully charged even when it’s not in use. Damage can occur to car batteries when they are not fully charged.
Extreme temperatures can also have an impact on car batteries. Car batteries can freeze once the charge level gets too low. To learn more about why car batteries can freeze if temperatures outside dip too low check out my other article can car batteries freeze?
Extreme heat can also have an impact on battery life as it can cause the liquids inside of the battery to evaporate causing damage to the battery. To keep your car battery lasting as long as possible it’s best to shield your car from extreme cold or heat.
If you are expecting extremely cold temperatures you’d want to park in an insulated garage. If you are expecting extreme heat you’d want to park under something that would shade your car from the sun like under a tree or in a garage.
If you plan on storing your car for a long period it’s best to hook up a battery maintainer to the battery to keep the charge topped off during the storage period. That way it isn’t damaged by allowing the battery charge to get too low.
How Do You Preserve Electric Car Batteries?
Electric cars (EV’s) and hybrid car batteries are a bit different than normal lead-acid car batteries that you would find in most cars on the road. EV’s and hybrid batteries are made up of lithium-ion batteries which are the type of battery that you would find in your cell phone.
Lithium-ion batteries don’t like to be fully charged all of the time or fully discharged. To maintain the longevity of lithium-ion batteries the battery charge should be kept in the 50-80% range.
Tesla advises against fully charging their car batteries to 100% charge unless you plan on going for a long drive where you need to use the full range of the battery pack.
You also shouldn’t allow your battery charge to drop below 50% with lithium-ion batteries. Allowing your battery to fully discharge below 10% can damage the battery pack over time and reduce the range of the battery pack over time.
Accelerating hard with an electric car can also damage your battery pack over time. With high-performance Teslas they specifically state that you can reduce the overall battery pack lifespan by launching your car from a stop.
But in general, if you drive your electric car normally and keep your electric car battery level from dropping below 20% that should help your electric car battery last longer.
How Do You Preserve Hybrid Car Batteries?
The same applies to hybrid batteries which are also comprised of lithium-ion batteries. But typically with hybrids, your car will maintain the charge of the lithium-ion battery pack.
So with hybrids, you don’t really have to worry about what level of charge the battery pack is at as long as everything is working properly. But if you are going to be storing your hybrid car for an extended period it’s best to keep both the car battery and hybrid battery pack charged.
The easiest way to do that is by periodically starting your car so that it will have a chance to charge your battery pack. You can also hook up a battery maintainer to your hybrid battery pack.
Related Questions
Do You Have to Replace A Car Battery After Jumping It? No, just because a car battery needed to be jumped doesn’t mean that it’s bad and needs to be replaced. If you are consistently needing to jump your car there may be a problem with your alternator not providing enough charge to the battery while the engine is running.
To learn more about the symptoms of a bad alternator check out my other article. If you are interested in learning how much it costs to replace an alternator check out that article.
But if your car battery is about 4 or 5 years old and consistently won’t hold a charge you should think about replacing the car battery with a new one.
Does A Car Battery Charge While Idling? Yes, your car battery will charge as long as your car’s engine is running and your alternator is working properly. You don’t need to drive around to have your alternator charge your car battery.
If you’d like to learn more about alternators and if they will charge your car battery while in neutral check out my other article does a car battery charge while idling.