Charge Laptop in Car: Guide & Tips

Hello, I'm having a problem where the laptop in the car sometimes turns off during data logging/reading.
Now I've seen a USB charging adapter that has a voltage of 5 volts and a current of 1000 milliamps.
Was wäre, wenn VCDS läuft und gleichzeitig eine andere Ladestation verwendet wird?
Same 12-volt potential, or something like that?
Or would it be better to go through the charging port?
"I was wondering, should I use a thin USB cable that only provides 1A of charging current?"
How do you do that?

I have a converter that transforms the 12V from the cigarette lighter socket into 18V for my laptop. It's working perfectly so far.

Hi,

You cannot charge a laptop via USB. A USB host port provides power, and a USB device can be powered or charged from such a port. Laptops typically only have host ports (the ones where you plug in USB sticks), while devices like smartphones or cameras are USB devices, meaning they can be charged via USB or a USB car adapter.

Furthermore, most laptops require significantly more than 5W of power; even small devices typically consume 10-12W in idle mode, while large gaming laptops can draw much higher amounts.

"For my 'Stone Age' laptop, which I use with VAGCOM, I have a universal car adapter that I bought on eBay for 15 euros back then. It converts the 12V from the car to the 16V that my laptop needs, and it provides, in my opinion, 4 amps (which is more than enough for the old Thinkpad). Just check the secondary output voltage of your laptop's power adapter and buy a car adapter accordingly. Universal adapters are not expensive and usually have an adjustable voltage of 16-20 volts and adapters for all sorts of cable types."

P.S. My equally archaic serial adapter, despite sharing the same ground, doesn't have any issues with this device.

Best regards,

Jan.

Hello,

Generally, one should be very careful when connecting circuits with different reference masses.
For proper operation, the ground connection at the OBD2 connector of the vehicle (which connects to the USB port of the laptop/netbook via the vehicle's diagnostic electronics) MUST have the same potential as the grounds of the laptop. This is either galvanically isolated from the mains power supply (which is ideal) or, hopefully, connected to the negative (-) terminal of the power supply.

Ungünstig wenn Sie von +12V, irgendwelchen internen Übertrager/Trafoabzapfungen etc. kommt, dann gibt das schwächste Glied in der Verbindung nach. Dasselbe gilt für Ladegeräte für die Fahrzeugbatterie und gleichzeitige Versorgung des Diagnoserechners aus der Steckdose. Steht also in the manual as well.

If someone uses something like this, please check the potential differences between the mentioned points beforehand!
Damages caused by unsuitable power supplies connected to the diagnostic hardware are therefore the user's sole responsibility.

Best regards, Rainer.

Hi,

Quote:

If someone uses something like this, please check the potential differences between the mentioned points beforehand!

"Yep, that's really important. In my setup, I measured exactly 0 volts between the ground of the laptop powered by the car's power supply and the ground of the diagnostic cable connected to the car, but not to the laptop – both with the engine running and when the engine was off. That's why I implemented it that way, and so far (that's been at least 6 years now) I haven't had any problems."

Best regards,

Jan.

Thanks for the answers. It should be 19 volts and 4.75 amps, so it needs an inverter.
Can it also be operated with less power, say 3 amps, and still function as a support?

teileklaus wrote:

Thank you for the answers; it should be 19 volts and 4.75 amps, so it needs an inverter. Can it also be operated with less power, say 3A, acting as a kind of support?

Hello Klaus,

How your laptop behaves when connected to a power-limited source depends on the laptop's circuit design.

The problem will mainly be that most laptop adapters are not truly current-limited. For example, if it's specified as 3A, that only means that a higher current draw may not necessarily be harmless. It doesn't necessarily mean that the current is limited to 3A. That is, the adapter could potentially break, or get too hot, or... --> Just let it .

Ich verwende ein Netzteil, dass bis zu 6A liefern kann. NTS 120.

"This allows VCDS to run smoothly on my laptop. The ground connection of the cigarette lighter is connected to the ground of the laptop charger. Inside the laptop, the laptop charger ground and the USB ground are connected."

That thing doesn't cost 18 euros.

Greetings.
Sure, here's the translation:

"Guste" is a German word that means "gust" or "gust of wind." It can also be used to describe a sudden burst of something, such as laughter or anger.

Okay, then I'll order the Reichelt 120 set.
Thank you everyone.

Okay, so in the Passat 3C, there's an optional 230-volt outlet. I don't know how much it costs from VW, but it's a nice feature, and I believe it can provide up to 150 watts of power.
You could also retrofit something like that, which would allow you to charge your laptop with the original power adapter.

Best regards, Mario.

It costs Volkswagen as much as a cheap notebook .

Yes, well, VWs are probably quite expensive.
I just checked on Amazon, and there are power adapters listed for around €15 that have a power output of 150 watts.
As an alternative to the laptop's power adapter, I think having a 230V socket in the car is a good idea. It would also allow you to connect other devices that you might need near the car.

I also have a similar device, IIRC it's the 150 model. It works with my old HP Pavilion and my newer Lenovo, both in diagnostic mode (VCDS professional system KKL+CAN), without any problems, but for the Lenovo, there wasn't a suitable adapter included, contrary to the catalog's claim.
"I actually made one of those thick tube connectors myself, using thin copper sheet with masking tape as insulation between the center and outer conductors. It looks a bit chaotic, but it's been working fine for over a year."

Hello everyone!

dieselheinz wrote:

As an alternative to power adapters for my laptop, I think a 230 V power outlet in the car is quite good, and it also allows you to connect other devices that you might need near the car.

Please remember that not all devices can or should be connected to such inexpensive inverters, as the output voltage does not correspond to a standard sine wave but rather resembles a chopped-up rectangle!
It may be true that devices with switching power supplies (TVs, small(!) power supplies with relatively high output power, cell phone chargers, etc.) are not affected by the shape of the AC voltage, as it is immediately rectified at the input. However, all devices with conventional transformers (e.g., classic car battery chargers, (the old, bulky) plug-in power supplies, other (small) battery chargers, etc.) are sensitive to non-sinusoidal input voltages and may burn out after a short period of operation (apparently without a clear reason).

If you want an inverter here that produces a true sine wave, you should expect to pay approximately 1 EUR per watt (not 15 EUR like you might find on some online marketplaces!).
With such a device, you can operate all 230V appliances without restriction, as long as the power consumption does not exceed the device's capacity.

Best regards from Munich!

...not for no reason, but the transformer is saturating due to the rectangular signal...

...and not unconditionally, because inductive loads or components with a negative characteristic can also overload such an inverter, even if the wattage appears to be correct on paper...

Best regards, Styrian.

Styrian wrote:

...not for no reason, but the transformer is saturating due to the rectangular signal... ...and not unconditionally, because inductive loads or components with a negative characteristic can also overload such an inverter, even if the wattage seems correct on paper...

Nicely observed, but since we're in a diesel mechanic forum, most people probably won't understand terms like "saturation" or "VA" instead of watts, right?

Best regards from Munich!

"No, I don't want that. I want to be able to shave and dry my hair in the car, but then I'd have to deal with 14 volts and a lot of energy loss, and then convert that to 240 volts, which would generate more heat, and then convert it back down to 19 volts, or even 12 volts again."
Hey Ulf, we don't want that, completely aside from the extra weight .

Okay, I understand volt-amperes. Saturation occurs when the oscillation process no longer functions properly in the transformer due to the waveform, and it's related to an additional primary current?
I'll stick with the Reichelt 120.