Soldering/power problems please help

[Phill7]

Recently I have been working on a project trying to charge my laptop that has only a DC input with a usb c power bank. The power bank outputs 45 watts and I took a 20v 3amp USB c cable and soldered it to a 20v 2.25amp DC cable. However, when I plugged this into my laptop no power was drawn. Any help would be most appreciated since my laptops battery life is horrendous let me know if you need any more details. 

[Enderman]

That's not how electricity works.

You don't plug a "20v 3A cable" into two devices and magically get 20V 3A from one to the other.

Both the power bank and laptop are DC. There is no AC anywhere in that system.

The power supply needs to output the voltage that the laptop is meant to receive, which can be found written on the power brick.

Your power bank probably only outputs 5V or 12V.

Laptops usually use 19V or something around there.

[Phill7]

1 minute ago, Enderman said:

That's not how electricity works.

You don't plug a "20v 3A cable" into two devices and magically get 20V 3A from one to the other.

Both the power bank and laptop are DC. There is no AC anywhere in that system.

The power supply needs to output the voltage that the laptop is meant to receive, which can be found written on the power brick.

Your power bank probably only outputs 5V or 12V.

Laptops usually use 19V or something around there.

My laptop uses 20v (2.25amp) and my power bank can also output 20v (2.25amp). 

[Enderman]

3 minutes ago, Phill7 said:

My laptop uses 20v (2.25amp) and my power bank can also output 20v (2.25amp). 

Yes but if it is a USB power bank it will only output 20V when it communicates with a validated device that supports fast charging such as a specific USB-C phone or laptop.

You cannot just hook up any device to it with a positive and ground wire and get 20V out.

[Phill7]

4 minutes ago, Enderman said:

Yes but if it is a USB power bank it will only output 20V when it communicates with a validated device that supports fast charging such as a specific USB-C phone or laptop.

You cannot just hook up any device to it with a positive and ground wire and get 20V out.

Makes since do you know of any way that I could trick the power bank to output 20v?

[Phill7]

2 minutes ago, Phill7 said:

Makes since do you know of any way that I could trick the power bank to output 20v?

Like maybe taking the circuit board out of a usb c cable and soldering the positive and negatives parts to the DC plug?

[Enderman]

11 minutes ago, Phill7 said:

Makes since do you know of any way that I could trick the power bank to output 20v?

None that I know of.

 

8 minutes ago, Phill7 said:

Like maybe taking the circuit board out of a usb c cable and soldering the positive and negatives parts to the DC plug?

Probably needs to be a working device on the other end, not just any circuit board.

[Phill7]

4 minutes ago, Enderman said:

None that I know of.

 

Probably needs to be a working device on the other end, not just any circuit board.

Thank you so much for the help, and one more question why can't my laptop pull the power itself? Sorry for all the questions 

[Enderman]

5 minutes ago, Phill7 said:

Thank you so much for the help, and one more question why can't my laptop pull the power itself? Sorry for all the questions 

Because you cannot pull electricity.

Only push it, with higher voltage.

[Phill7]

2 minutes ago, Enderman said:

Because you cannot pull electricity.

Only push it, with higher voltage.

Thank you for your answers they have been very helpful. 

[Daysy]

USB Power Delivery (USB PD) is the protocol that would allow your power bank to deliver a 20v charge voltage to your laptop. It's an open standard so in theory you could make your own client side port to charge your laptop from but it would be a seriously in depth project