Charging Laptop in Car

[Jerry202]

So I have a 2019 Razer Blade and it has a 200W power brick. Will just a 200W power inverter work for charging or should I go with a higher rating?

[Levent]

This depends on your car to be honest. You have to check the current limits of the 12v socket. Most passenger cars are 5A limited. You might get away with a USB PD charger, as long as you dont use your laptop while charging.

[dalekphalm]

2 minutes ago, Jerry202 said:

So I have a 2019 Razer Blade and it has a 200W power brick. Will just a 200W power inverter work for charging or should I go with a higher rating?

I would go for a higher rating. The 200W Inverter would work on paper, but you'll be maxing the unit out (and if it's not well built this could cause serious overheating, among other potential issues).

 

Grab something like a 250W inverter instead - gives you headroom in case either company is being "generous" with their specs.

[dalekphalm]

Just now, Levent said:

This depends on your car to be honest. You have to check the current limits of the 12v socket. Most passenger cars are 5A limited. You might get away with a USB PD charger, as long as you dont use your laptop while charging.

Yes good point, you want to ensure that the car can even safely output the amount of wattage you need.

[WereCatf]

3 minutes ago, Levent said:

This depends on your car to be honest. You have to check the current limits of the 12v socket. Most passenger cars are 5A limited. You might get away with a USB PD charger, as long as you dont use your laptop while charging.

I was just about to mention this myself. OP will blow a fuse, if they try to pull 200W out of the socket in a typical car. @Jerry202you'll typically find the maximum you can pull in the owner's manual for your car.

[Jerry202]

The AC Input on the power brick says 100V-240V ~ 2.5A and DC output says 19.5V at 10.26A.

Would my amperage limit be based on the input to the brick or the output to the laptop?

[Jerry202]

Thanks for the quick replies btw, love LTT fans.

[Levent]

2 minutes ago, Jerry202 said:

The AC Input on the power brick says 100V-240V ~ 2.5A and DC output says 19.5V at 10.26A.

Would my amperage limit be based on the input to the brick or the output to the laptop?

Basic electrical knowledge for ya. If your brick is rated for 100v-240V at 2.4Amps, it would consume around 240W. Voltage*amps=watts. Your main limiting factor is your cars 12v socket and its current handling capability. If its 12v at 5amps, it can only supply 60W without the DC to AC then AC to DC losses. 

[Jerry202]

19 minutes ago, Levent said:

Basic electrical knowledge for ya. If your brick is rated for 100v-240V at 2.4Amps, it would consume around 240W. Voltage*amps=watts. Your main limiting factor is your cars 12v socket and its current handling capability. If its 12v at 5amps, it can only supply 60W without the DC to AC then AC to DC losses. 

Here's the wiring diagram to the lighters. I'm pretty sure it says I get 20A to them but can I just get a double check?

[Jerry202]

Well, it has 20A fuses, Idk about the amp rating going to the connections.

[Jerry202]

Honestly what's the worst that can happen? I just blow that fuse and have to change it? Or can I damage the laptop in any way?

[Selle]

Worst case is your car catches on fire if the wirering isnt up for the load, but most likely you will only blow a fuse. 
 

If you only use it to charge the laptop while it is turned off you will most likely be fine

[dalekphalm]

59 minutes ago, Selle said:

Worst case is your car catches on fire if the wirering isnt up for the load, but most likely you will only blow a fuse. 
 

If you only use it to charge the laptop while it is turned off you will most likely be fine

To be fair, if his fuses are 20A but the wiring is only capable of handling 5A or so, then his car is literally a ticking timebomb that is going to burn to the ground sooner or later anyway.

 

1 hour ago, Jerry202 said:

Well, it has 20A fuses, Idk about the amp rating going to the connections.

Let's assume that your 20A fuses are correct and the wiring is matched to handle the current load.

 

That gives you a maximum of 240W of available power (12V * 20A = 240W). Your power brick will draw more power than it supplies to the laptop (due to inefficiencies in all electronics). If we use the smallest voltage value, your power brick will consume upwards of 240W (or possibly higher - if we assume the inverter supplies 115V or 120V instead of 100V - since 100V AC is actually pretty rare - your Wattage might be as high as 276 to 288W).

 

It's close, but could be doable. If you were to only charge the laptop while it's shut off, I think - assuming fuses and wiring are actually 20A - that you would be okay.