Forgetting to Charge Your PHEV: The Risks and Potential Damage

PHEVs are, of course, different from your typical hybrid vehicle. The clue is in the name. PHEVs can be plugged in every so often to charge the battery. if there is no charge in the battery, then the vehicle will automatically switch to running on gasoline instead.

Now, while it is suggested that you charge a PHEV, do you need to charge a PHEV? What happens if you don’t charge a PHEV?

If you don’t charge a PHEV, then your vehicle is essentially just going to be a gas vehicle. It won’t really run on the battery at all. There won’t be enough juice in the battery to run the motor. Your vehicle won’t stop. It will just run on gas instead.

Let’s take a look at this in a bit more depth, shall we?

Do You Need To Charge a PHEV?

No. You do not need to charge a PHEV. However, it would be rather pointless to own a PHEV and not charge it.

The whole idea behind a PHEV is that it can run on both battery power and on gas power. It will run on the electric battery as standard. However, if the electric battery runs out of juice, it will switch over to gas power. This should be, at least with most PHEVs, a fairly seamless transition. 

What Happens When PHEV Battery Runs Out?

Assuming that you have gas in the tank, your vehicle will just start running on that instead. As we said before, this is going to be a fairly seamless transition.

If you never charge your PHEV battery again, you will be able to continue to use your PHEV as you would with a normal gas-powered vehicle. However, at that point, it would be rather pointless to own a PHEV. You are eliminating pretty much the main advantage of ownership.

If you don’t think that you are able to keep up with your standard PHEV charging, then it would be better to roll with a hybrid instead. A hybrid would at least be able to keep a bit of juice in the battery, even if it is not going to be as fuel-efficient as a fully-charged PHEV would be. 

Don’t worry. As long as you have fresh gas in the tank (more on that in the next section), your vehicle isn’t just going to stop working. It will continue to work. You aren’t going to be stuck in the middle of nowhere like you would be if you were driving a fully electric vehicle. 

What Happens If You Don’t Charge a PHEV?

By now, you know that the vehicle is going to keep running as long as you have gas in there. However, there are a few things that we need to point out. This is because things aren’t quite as simple as you would expect.

Gas Expires

This is an issue that many people are not aware of, mostly because many people have driven gas-powered vehicles for their whole lives. It isn’t really an issue that enters the equation if you are driving a hybrid vehicle either. After all, with a hybrid vehicle, that gas is still going to be burned away. It just isn’t going to be burned away as in a full-gas vehicle.

Gas has a shelf life of around 6-months. If it is sitting around unused for longer than that, then the quality of the gas will start to degrade. If the quality of the gas has started to degrade, not only is it going to be less efficient when burning, but it could end up dropping all sorts of contaminants inside of your engine. It isn’t fantastic.

Because a PHEV can easily go a good distance before the battery powder dwindles away, most people’s PHEVs very rarely switch over to gas. This is especially common for those that are using their PHEV purely for commuting. They will still keep gas in the tank, though.

This means that if you don’t charge your PHEV and there is old gas sitting in the tank, then it could be pretty hard on the engine. It may not destroy it, but your vehicle certainly won’t be pleasant to drive.

Your Fuel Efficiency Will Be Very Low

PHEVs have very large batteries. This is what helps them to run on a battery for longer periods of time than a hybrid vehicle would run.

Of course, if you aren’t charging your battery, that battery doesn’t just disappear. You still have that whole set-up inside of your vehicle. It is very, very heavy too.

If you are not charging your vehicle’s battery and it is running constantly on gas, then the fuel efficiency is going to be absolutely woeful. It is going to be far less fuel-efficient than almost every gas-powered car out there, and it is certainly going to be a lot less fuel-efficient than a hybrid vehicle.

So, once again, we want to point out that if you are not charging your PHEVs battery and keeping it charged, you are pretty much eliminating the only benefit that a PHEV offers over hybrids and their gas-guzzling pals.

In fact, not only are you going to be eliminating the only benefit that is there, but you are also going to be doing it in a way that makes things much worse for yourself. You aren’t just bringing your PHEV on-par with a gas-powered vehicle or a hybrid, you are making it much less fuel-efficient than both of those.


A PHEV is designed to run on both electric and gas. If the battery runs out, then the gas will kick in. So, if you don’t charge your PHEV’s battery, then your vehicle will essentially become a gas-powered vehicle.

However, this doesn’t mean that you should avoid charging your PHEV. If you don’t charge it, then your fuel efficiency is going to be awful, and you are going to be eradicating the main benefit of owning a PHEV.