I've left my lights on and car won't start

I’ve Left My Lights On, And Car Won’t Start. Now What?

Sometimes we all get a little carried away and forget to turn off our headlights or interior lights or both when leaving the car. Maybe you’re late home after a long day, and all you’re craving is the warmth of your bed. Such days happen, and you wake the next day to a car that won’t start or a car with lights on.

When you’ve left the lights in your car or headlights on for a long time without the car running, it tends to drain your car’s battery. A car’s battery gets recharged when it’s on the move; that’s why you can charge your phone, listen to music, and even turn on the headlights and interior car lights. When the car is running, it replenishes its battery. 

It is more likely that your car will survive overnight with the headlights or any other lights on. The moment the lights are on, it means that your lights are getting energy from your battery without recharging it. It is even unlikely that those headlights will still be on in the morning when you come back to check them. 

You might have turned off your car and your lights, but other reasons could cause your lights to stay on even though you’ve turned both off, like;

  • Leaving your car boot a bit open
  • Not completely closely your car doors

The car detects such issues and, as an automatic reaction, turns on the lights. When leaving your vehicle, make sure you shut all doors entirely so that you don’t come back to a car that won’t start. That can be very frustrating. 

I've left my lights on and car won't start - Car Batteries1


What happens if you accidentally leave your car lights on?

Car batteries are not designed to keep the systems in your car running for a long time without the engine recharging them. Car batteries can only maintain their charge when you drive the car since the engine gets active and recharges it. 

When you realize that you left your car lights on for way too long than you should have, check your battery to see if it’s still in the proper condition. If you have a healthy battery, you might need a jumpstart, and you can go on with your day. Leaving your car lights on will only drain your battery which could cause stalling the next day or even inability to start your car. 

When the lights are on in your car and the engine isn’t running, the battery will drain as it tries to keep the lights on. Depending on your battery’s condition, this could mean buying a new one or recharging the available one. 

Unfortunately for you, your car insurance won’t be able to cover the cost of your battery replacement or towing your car (if need be) because battery problems are something that falls under maintenance, and you don’t have that kind of coverage. All the financial help you need will have to come from your pocket, even though leaving the lights on was an accident. 

Will my car battery die if I leave my lights on? 

The life of your car’s battery depends on how long you leave it on. How full your car battery is and how new or old it is will determine just how long it can keep the lights on and still be able to start when you switch it on. If your battery is brand new and in good condition, it could last for a few hours, definitely not the whole night. But if your battery is not in good condition, it might not even last an hour. 

The condition of your battery determines a lot. If your car has an old battery that you’ve probably changed for years, leaving the lights on when the engine isn’t running will mean that you might need to get your car a new battery. 

On the flip side, whether you have a brand new battery in good working condition, you will come back to your car with a dead battery that will need charging. Unlike an old battery, you won’t need to buy a new battery. You could jumpstart your battery if you know how to do that or with the help of your mechanic; soon, you’ll be back in your car running errands. 

Sometimes you might forget to close your car’s door all the way. Leaving it open could trigger your internal lights to stay on for the entire time you’re away from your vehicle. Even though some cars have an automatic turn-off, others don’t. You can save your battery by jump starting it, but you might kill your battery if you make this mistake several times. 

How long does it take for a car battery to die with lights on?

It is a bit difficult to give the exact numbers as it all depends on your battery. For some people, leaving the lights on for four hours still means that you can still come back and start your car successfully, while others can’t leave their car’s lights on for over thirty minutes without the battery giving out and needing charging or a jumpstart. 

An average car battery will take between thirty to ninety minutes to drain your battery completely; this will mean that you’ll need to jumpstart or recharge your battery. But if left for several hours, your battery might not survive either. It is possible that leaving those lights on for too long could kill your battery altogether, needing you to buy new ones. 

Will a dead car battery recharge itself?

No. A dead car battery can’t recharge itself. To get it charged and working, you could take it out and charge it or jumpstart it with another battery or another car. There’s no type of car battery that can charge itself without external help. 

Once you’ve left the lights on and now your battery is dead, not even the alternator will help recharge your battery. Another alternative to charging up your car battery is jump starting it and then running the engine for a while. 

But if you can access a mechanic, they could help by using special battery chargers to recharge a battery temporarily. Your car will keep recharging the battery once you’re on the road. 

There are different ways that you can recharge your battery. These include; 

  • Using another car’s battery: You can do this using jumper cables. Connect your dead battery to the one that’s running, and it will restart your battery within no time. When doing this, make sure you take safety precautions to prevent hurting yourself. 
  • Car battery charger: You can use a battery charger to connect your battery to an electricity socket and leave it there for up to twenty-four hours to charge your battery fully. 
  • Drive around: If your battery still has a bit of life left in it, don’t give up easily. Drive around to charge up your car’s battery. Driving around would require your battery to have a bit of life still left in it.

You should take safety precautions when charging jumpstarting a battery by yourself if you haven’t done it before. These are;

  • Wear gloves and protect your eyes
  • Make sure that both batteries are of the same voltage. 
  • Take off any loose clothing or jewelry
  • Ensure that both cars aren’t touching each other. 
  • Ensure that the jumpstart cables are positive red. 
  • Don’t touch the clams while the vehicle is running.
  • Don’t look directly at the battery when connecting the clamps.
  • Ensure you don’t connect the negative clamps to any car body part.
  • Always use the red positive jumper cable first. 

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Who’s the best service when I have a dead battery?

Mach1 roadside assistance is the best service to jumpstart your car anywhere, any time of the day or night. They are service-oriented, with mechanics and partners in every state. You will be charged a fair market price according to your region. Don’t be afraid of getting overcharged because that’s not what Mach1 does. 

If you’ve broken down and you think it’s your battery but aren’t sure, you can order for a mechanic on their free app, and when the mechanic comes, you can add a jumpstart to your order. 

With the Mach1 free app, you can access roadside assistance services without signing up to be a member. The only fees you’ll be required to pay are ones of the services you’ve ordered via the app. You can pay via the app or through a debit, credit card. 

When you have a dead battery, all you need to do is download the Mach1 app, input your location, and order a dead battery service. Soon enough, help will be dispatched, and the maintenance team will inform you about how long it will take for help to arrive. 

If you’re on the highway roadside, you can turn on your emergency lights and stay in your car. But if you’re not on the highway and your environment doesn’t look very crowded, you should lock yourself in the car and keep safe until help arrives. 

Mach1 services are cheap as they charge according to the market price in your area and will arrive on time since they have partners in most cities and towns. For a dead battery and any other road assistance emergency service you might need, Mach1 is the best. 


Leaving your car lights on can be an utterly accidental thing, but your battery has no idea that it was accidental and will still drain. The life of your battery will determine just how long it can keep the lights in your car on and not completely die to the point of needing replacement. A strong battery will endure draining its charge to keep the lights on, but you’ll still need a jumpstart. 

As much as leaving your lights on is an accident, you shouldn’t get in the habit of it. The more your car lights stay on; the more susceptible your battery is to dying earlier and not serving you for as long as you need it to. Replacing your car’s battery very often could result in you spending too much money, which is expensive. 

Always ensure you’ve locked your doors properly and trunk to prevent your lights from turning on and draining your battery. But since this is something accidental, whenever you need help with a dead battery, Mach1 services are the best roadside assistance services to contact to revive your battery.