How long should a car run after getting a jump? Boy, oh boy, is that ever a complicated question to answer. On the surface, it doesn’t appear as if there would be very many complications. Truthfully, it’s not as if there are a dozen or anything like that.

The reality of the situation, however, is that this question needs to be addressed and analyzed in a few different ways. There are some outside variables that will greatly alter the answer to the question. That’s where the complications are going to come into the fold.

Now, some people know all too well about the problem of a vehicle not starting due to a dead battery. Jumpstarting a vehicle is the solution that many will employ to attempt to get their car up and running again. And that leads to the question of this post. How long should a car run after getting a jump?

For a brief answer, it’s going to depend greatly on whether or not the vehicle’s alternator is functioning properly.

With a failed alternator, a car (after getting jumped) needs to head directly to the nearest mechanic for a replacement (and the vehicle might not get very far).

With a functioning alternator and a dead battery, it’s going to vary how long it takes to fully recharge the battery (from 30 minutes to several hours).

Oh, and what happens if you’re trying to get a jump in the bitter cold in the middle of the winter? That can play a significant role too. But, to start, let’s look deeper into the issue of jumpstarting a vehicle with a bad alternator.

A failing alternator makes for a different beast altogether

Photo by Joshua Aragon / Unsplash

The reason the battery in your car stays charged is due to the alternator. It’s vital and if the alternator isn’t working properly and charging the battery, problems are going to arise. A simple jumpstart of the battery isn’t going to fix a faulty alternator. So, in other words, if this is the issue, it needs to be addressed firsthand, right away.

However, you can possibly avoid needing a towing service if your destination to get the alternator fixed is in close proximity to where you are (very close). Seriously, you may only get five minutes until the battery dies again. In other words, you can jump the battery but you’re taking a massive risk of being stranded.

Of course, if you have a jumper pack (which is a portable jumping system that allows you to charge the battery in your vehicle without the assistance of somebody else), you could still provide yourself with a jump without any help.

Still, if the alternator needs to be replaced, the answer to the question of how long should a car run after getting a jump would be, “not very long…as in a couple of minutes maybe.”

The good news is according to Firestone Complete Auto Care, alternators will typically last the lifetime of vehicles. It doesn’t always happen that way, however, so don’t just assume that it will never be an issue for you.

How long should a car run after getting a jump if the alternator is perfectly fine?

As mentioned earlier, this whole question becomes much different if the alternator in your vehicle is functioning as it should. With a dead battery and an alternator ready to charge it (which will only occur if the vehicle is actually running), a jump can allow the alternator to do what it does.

The appropriate question then becomes how much driving would it take to fully charge the vehicle’s battery? Generally speaking, the battery is going to charge faster at higher speeds. The more RPMs (revolutions per minute) the engine generates, the faster the battery is going to charge.

So, if you’re traveling at speeds 55 miles per hour or faster, the recharge time is going to be faster. At highway speeds, most vehicles will need about 30 minutes for a full recharge. That’s just an average, though, and it may take longer depending on how severely discharged the battery is.

What about when the car is idling?

How long should a car run after getting a jump is a very different topic when you take into consideration the following. Are you allowing the vehicle to sit with an idling engine? After all, the battery will still be recharging in this state, but it’ll be doing so at a much slower rate as opposed to if you were driving.

Not generating a lot of RPMs will result in your car battery taking much longer to charge. And this isn’t talking about a few additional minutes, either. Several hours would be necessary to recharge your battery this way, so it’s probably best to drive it around and give it some higher speeds.

The problem when you need a jump in the winter

If a VW van can look unhappy, I’m sure this is it!
Photo by Dan Freeman / Unsplash

Anyone who’s had to get a jump to get their car started knows that it’s not an enjoyable experience. Yet, it’s even worse in the winter. Even if you have a car battery in good condition, it’s going to lose half the potential power it has at 0 degrees Fahrenheit. Additionally, fluids will thicken more, and more battery power will be required to start the vehicle.

Thankfully, there are a few different ways to prevent a jump from needing to be done in the winter:

  • Replace the battery. Yeah, we know, more money. However, buying a new battery with the highest CCA (cold cranking amps) rating possible for your vehicle can help a lot. Of course, if you just installed a new battery, the hope is that you bought one with a good CCA rating.
  • Install a battery blanket. A blanket to help heat your battery. Huh, they’ve really thought of everything. Indeed, this is a thing and a heated blanket specifically for your battery can help prevent the battery from losing power and voltage when it gets cold.

How long does the average car battery last?

Photo by Daniel @ / Unsplash

If you need to know, “how long should a car run after getting a jump,” then, chances are, it might be getting close to a battery replacement in your vehicle. That leads to this next question. How long does the average car battery last?

It depends on who you ask as the answer may be slightly different. The general consensus, though, is three to five years. Some cars may be able to get six years out of a specific battery, while others may be lucky to get just three. It depends because there are various factors that can shorten battery life. Speaking of which…

What are some of the factors that can affect battery lifespans in vehicles?

As mentioned, there are quite a few factors, and the following are some of the most common:

  • Leaving your interior lights or headlights on for several hours while your vehicle is parked.
  • The battery terminal connections are either loose or corroded (or starting to corrode).
  • The battery itself is simply in poor and old condition and needs to be replaced.
  • Leaving your car parked for extended periods of time without driving it.
  • The charging system experiences some type of failure.
  • The vehicle is taken on a lot of short driving trips in a row, thus draining the battery very quickly.
It’s good to get in the habit of taking a 30-minute highway drive at least once a week to give your alternator the time (and speed) it needs to fully recharge your battery.

On a side note, and it’s on topic, you can also kill the battery if you leave the radio on for too long with the engine off. However, how long would it take for your car battery to die with the radio left on?

Here are some signs to indicate that your car battery is low

To wrap this up, let’s discuss some warning signs that you can look for that can possibly indicate your car battery is close to expiring. After all, you can possibly prevent the need for ever needing to know how long a car should run after getting a jump.

  • Your car is taking longer to start. If you notice that your engine is cranking longer than it used to (and that the ignition is not turning over as fast), the battery’s charge could be getting weaker. Of course, getting your vehicle to turn over in the frigid, cold morning is going to be harder than usual. So, don’t mistake that for a potentially bad battery.
  • The interior lights are not as bright as they used to be. Outside of this, your vehicle may also have a dashboard light that will come on to indicate the battery is low.
  • Check the battery for damage. Look for corrosion and cracking. Additionally, check for a pungent sulfur smell. Any signs of that type of stuff will mean a battery replacement is in store.

Final thoughts

So, how long should a car run after getting a jump? It’s sort of a difficult question to answer. If the alternator in your vehicle is functioning the way it should, a highway drive of possibly an hour or two (or potentially even less) could fully recharge your battery if you had to get it jumped.

On the flip side, you’re not going to be able to run your vehicle for much time at all if the alternator is junk. You’d maybe have a few minutes to get it to a local mechanic. The goal is to not need a jump, in the first place, so keeping an eye on your battery and practicing good driving habits are very important.

And, before you go, do yourself (and us) a favor by checking out our post detailing whether or not there are any battery-operated heaters on the market.