The good news is that 70 miles is more than enough to charge up the battery. Whereas, when you are driving the same car in a busy traffic scenario, it can take up to 1 hour or more to charge the car battery. I have been working with cars for 10 years, specialized in diagnostics and troubleshooting. You also have to take in mind the kind of car battery. So, here is a recap of some of the key points. It can be low from lights being left on, an internal failure, extreme hot or cold temperatures, a failing alternator, long term storage without being used, or any number of other reasons. Worse yet, you can’t determine the core temperature of a battery by measuring the temperature of the case. Idling or going for a short start trip would partly recharge it so you can survive until you can recharge it properly. The battery now has a weak charge but it can get the engine started (barely). Let the dead battery charge for a few minutes, and then turn the ignition on the vehicle of the dead battery to see if it starts. The most common rate for car battery chargers is around 4 amps. A trickle charger, will put a very slow charge to the battery and bring it back from the dead. This is unlike the sort you get in cameras, etc - older NiCads especially- , which don't like being recharged when not fully discharged. So how long will it take for you to hit the road again? Even after considering the fact that your battery is dead, it will not take an eternity for your battery to charge. Whereas, when you are driving the same car in a busy traffic scenario, it can take up to 1 hour or more to charge the car battery. I would like to charge the battery by running the engine, but because my brakes are currently not working, I cannot take it for a drive. What if you were driving inter-state one day and right in the middle of a jungle, your car battery dies? If you let your vehicle idle for about 20-30 minutes (depends on how many RPMs your engine idles at) that should return enough charge to restart later without trouble. How Long Does it Take to Fully Charge a Tesla? You are in a hurry on the way to work, and you jump into your car and quickly turn the key – Nothing happens. What to do when Car Battery is Dead & What Causes it? Modern chargers are easy to connect and have battery charging monitoring, which will regulate the amps themselves. If a battery is deeply discharged it will not charge up properly with an alternator. The best way to charge a car battery is slowly. If it doesn’t, the battery might need to be replaced. How Long Does it Take to Charge a DEAD Car Battery? This is why we strongly advise that a car battery is recharged whenever there is a need for it. How Long to Drive A Car To Recharge the Battery Again, there is no specific correct answer. I created this blog because I was tired of finding false information on the web while looking for repair information. Here are 100 more car maintenance jobs you can do on your own. When driving your car on high-speed lanes, charging of the car battery will take up to 30 minutes on average. In this post we’ll cover battery charging by driving quick tips and the associated risks. 2-4 ampere is typical for maintenance charging, and it will take around 24 hours to fully charge a dead battery at this load. Charging a dead car battery takes 4 to 24 hours for a full charge, depending on how many Amperes your car battery charger is charging with and your car battery’s size. Low ampere is better for maintenance charging of your battery over long periods. Long-time charging with low amps is the best for keeping the battery’s lifetime long. After jumping a dead battery, drive at least 30 minutes to allow the alternator to bring the battery back to an acceptable level so that it will start again on its own. To fully charge a battery of the size 52Ah would take about 10 hours from dead to fully loaded, but you could probably start your car within 1 hour. The vehicle charging system will not completely recharge your vehicle system in an efficient/prompt manner or in a manner that will maintain a long battery life after a deep discharge event.