My Battery Reads 12.5 Volts but Why It Won’t Start?

If your battery reads 12.5 volts but won’t start, there are a few things you can try. The easiest solution is to check the connections on your battery. You might have a loose connection somewhere, or maybe a wire is frayed or broken inside the terminal.

If you find that one of these issues is causing your problem, tightening the terminal or replacing the wire will fix it right away. If that doesn’t work, you may have a faulty battery. A car battery should last at least five years before needing replacement, so if yours is older than that, it may be time to replace it with a new one.

If none of these solutions seem to be working for you and your car still won’t start after checking all of these things, then it’s time to take it into an auto shop for professional help.

Why is this important?

The battery on your car is the heart of the electrical system, and it’s important to understand what 12.5 volts means, why that number is important, and how you can keep it in a good range.

Let’s talk about what those numbers mean. The voltage measurement tells you how much energy is available for use by your car’s electrical system. The higher the voltage reading, the more energy is available for use by the electrical system and the more power-efficient your car will be.

What happens when the battery reads 12.5 volts?

Your car’s battery provides the power necessary for your engine to turn over and start. If your battery isn’t working properly, it can cause all sorts of issues with your vehicle’s electrical system.

If you check your battery and it reads 12.5 volts or higher, it’s still good! You can use this to troubleshoot other possible problems. If you check your battery and find that it’s below 12 volts, then it needs replacing as soon as possible you may have a bad cell in the battery or something else wrong with it that could lead to more serious issues down the road.

Why do batteries read 12.5 volts and not other numbers?

If your battery is reading a number other than 12.5 volts, then that means something is wrong with your charging system. If you try to start your vehicle and nothing happens, it may mean that the alternator is not charging the battery properly. In this case, your battery needs to be tested or replaced before you can drive again.

What are some signs that your car battery might be going bad?

One of the most common signs that a battery is going bad is that it won’t start the car. If you’ve got your keys in your hand, turn the key and nothing happens, or if you’re trying to start your car and it turns over but doesn’t catch and start, then your battery may be at fault.

The first thing you should do if this happens is to check your battery’s voltage level if it reads less than 12.5 volts, then you’re going to need to replace it. Another common symptom is that the lights on your dash are dimmer than usual this could mean that your alternator isn’t working properly and needs replacing as well.

How long has it been this way?

If your battery has been reading 12.5 volts for a while, the problem could be one of two things: either your battery needs to be replaced or your alternator is failing.

If you’ve noticed that your battery keeps dying after only a short time of use, then it’s probably time to replace it. If you’re unsure whether or not it’s time, then try charging the battery with a charger and see if it holds its charge overnight. If it doesn’t, then you know that you need a new battery.

If you have an alternator that’s failing, then the best thing you can do is take it in to get checked right away. Alternators have become more expensive than they used to be, so don’t wait too long before getting yours fixed.


The 12.5 volts the battery is reading isn’t enough to start the car. This can happen if there’s a problem with your alternator, or if you’re trying to run too many accessories while the engine is off. If you’re just trying to start the car and it won’t turn over, but your battery reads 12.5 volts and there are no other issues with your car, this could be caused by a bad starter.

Steven Hatman
Steven Hatman

We break down every information into easy-to-understand articles that cover all the categories anyone who owns a car needs to know about, such as oil , brakes , tires and etc. Our car guide is free and updated regularly for you to use as a resource, not only when you have an issue with your car but even before buying a new or used car! We also give tips on what to look for in each category or part of your vehicle.