I’ve just written a post about the battery charging problem in Peugeot vehicles and got some questions about the same issue in Volvo cars. Although the message is pretty similar saying “12V battery critical charging fault”, the reasons and solutions are different.
If you see this message in your Volvo (often with an adorable turtle pictogram), the reason may be the software issue, the alternator, the dying 12V battery, or one of the electronic control modules that have an impact on your battery.
Unfortunately, DIY diagnostics will not always work due to very complicated technologies and the need for an expensive scanner to read the fault codes in all the modules. But I will try to give you some ideas.
What cars are affected?
Any modern Volvo vehicle can throw this message. This is most common for the XC90, XC60, and XC40 and it doesn’t matter if there are pure gas, hybrid, or battery electric vehicles. They all have a 12V battery and several modules controlling it.
Surprisingly, this happens a lot with new Volvo vehicles that have just one or two thousand miles on the clock. So, the battery death is not probably the most obvious reason. Let’s look closer!
Common reasons for this message
So, the “12V battery critical charging fault” says that the 12V battery in your vehicle isn’t currently getting proper charge. In a fuel-powered vehicle, this originally means that the charging system can’t provide the battery with 14.0-14.7 volts to boost its charge.
So, every time you start the engine, the battery is losing its charge and it won’t compensate for the losses after that. If you keep driving, the battery will die and leave you stranded.
Here are the most common reasons for this message:
1) Control module issues (or software)
Volvo perfectly knows about this problem. In the US, they even sold a part called “Total Upgrade”. This is a small control unit that fixes some communication issues in the XC90 and XC60 exactly to fix the charging glitch that killed the battery very quickly.
While some owners claim that the “Total Upgrade” part managed to fix the issue, some others say things got even worse.
I believe there is a huge bug in the software and instead of reinventing all the software from scratch, Volvo decided to issue some kind of additional control module that would fix the wrong signals. But it’s a doubtful way to treat this problem, in my opinion.
2) Battery drain
You’ll be surprised how fast a battery can be drained these days. I know one person with the Volvo XC40 who got this problem after two weeks of owning the vehicle. It appeared to be a small piece of plastic that got into the hatch door and prevented it from locking properly. So, the light in the trunk was always on.
If you don’t lock your Volvo, it stays active and may be draining the battery heavily. After just two days of chilling in this condition in your garage, the car may not start and the battery may have ridiculously low voltage.
The vehicle may also throw other error messages and do some weird things like clicking relays, appearing and disappearing warnings, etc.
3) Alternator malfunctioning
If you have a hybrid or pure ICE car, the alternator must charge the battery. If something goes wrong with this part, the charging voltage may drop.
The problem may be with the alternator itself, with the voltage regulators, or with the wires connecting the alternator to the electricity system in your car.
To check if the alternator is working, measure the voltage on the battery terminals when the car is started. It should be 14.5-14.7 volts when the battery is charging.
4) Common hybrid problems
Some hybrid systems in Volvo cars charge the 12V battery using the 48V hybrid motor generator. In this case, there is a voltage regulator that reduces the voltage to charge the battery properly.
If this voltage regulator fails to do its job, your battery gets 48V and dies at the same moment. If you connect the multimeter to the battery after such an event, it will probably show something like 5-6 volts and the car won’t start.
5) Connectivity problems
Some dealer mechanics and Volvo owners admit there is a connection between the battery charging problem and the TCAM problem. Owners notice that when TCAM (Telematics and Connectivity Antenna Module) is glitching, they may randomly see the charging fault message.
I don’t know if this helps, but it’s worth checking the TCAM as it’s proven to be very faulty in the latest Volvo generation. Also, I can’t confirm that there is a connection between these two problems but forums are filled with this guess.
What does a turtle pictogram mean?
Very often, the “12V battery critical charging fault” error message pops up along with the “turtle”. This is the pictogram that says about the limp mode. The engine control unit has just cut the power of your vehicle.
You may still drive, but the power will be minimal to maintain a speed of 10-20 MPH. Why so? Because your Volvo thinks there is a problem with the alternator. To avoid further damage, it doesn’t let you rev up the engine or use up a lot of power from the hybrid system.
What can you do to solve the problem?
Well, to fix this problem, you will need to go to the dealer and ask for proper diagnostics. After that, the mechanic will tell you if there is a problem with the software, control module, or just with the dead battery.
Without a proper diagnosis, you can’t solve the issue on your own. But there are some things you may try doing to avoid paying for a tow truck or waiting for roadside assistance.
Here they are:
1) Jump-start the car
If the vehicle doesn’t start, you may try jump-starting it. Before you do so, have a look at the driver’s manual for your Volvo. There is a different process of jump-starting the vehicle for all kinds of hybrid cars and you shouldn’t experiment with this!
After jump-starting, the message usually disappears or at least lets you drive the car, maybe even in the limp mode, as described above.
2) Disconnect the 12V battery for some time
This may or may not work for different vehicles because sometimes the hybrid battery may back up the system and it won’t allow the electronic control modules to reset properly. But, in many cases, battery disconnection will reset the control modules.
Disconnect the battery (start with the negative terminal), press the honk or anything else to use up the remaining power, wait for 5-7 minutes, connect the battery, and see if the problem disappeared.
If the battery voltage is still OK, the car may start and go without any messages. But remember that this isn’t the fix – it’s just a temporary thing to try and drive your car on your own instead of calling the tow truck.
3) Use your multimeter and check the voltage patterns
This problem is tightly connected to voltage, so measure the voltage when the vehicle is off, when it’s cranking, and when it’s on. It should be 12.5 volts when off, not less than 11-11.5 volts when cranking, and 14.0-14.7 volts when the engine is on and charging the battery.
By doing this, you may have a better idea of what’s going on with the car. But sometimes, wrong readings can be obtained because of the control module issues and software problems. Keep this in mind.
4) Have the software upgraded
Although the dealers may not confess they know about this issue, they really do because this is an extremely common problem with almost all new Volvo cars.
So, take it to the dealership and let mechanics inspect the vehicle. Usually, this takes about half an hour to see the actual reason for the problem. Sometimes, they will just charge the battery, but in most cases, the dealer will upgrade the software or even replace the faulty control modules.
Can you drive with this message?
Whenever you see the “12V battery critical charging fault” message in your Volvo, you should understand that the battery may not be getting any charging voltage at all. This means that it can be drained after some time. Depending on its current condition, it can be several minutes or several hours.
So, if you are on the highway, make sure you take the first chance to stop. But don’t panic – the car won’t die immediately.
If you have Volvo roadside assistance service available, use it. If not, call the dealer and ask them to pay the tow truck bill. Fortunately, Volvo dealers are often very client-oriented, so they may solve the problem for free even if the warranty period is over.
Do you have any experience dealing with this error message in a Volvo car? Please share it in the comments below!
