Laptop car charger help

joey1211 · 11 Apr 2023 at 14:27

A bit late in the day but wouldn't you have been better off with a tablet and detachable keyboard? What are you doing that needs the power of a laptop?

Edit: Oh, just searched the laptop and it's a gaming one.

AtaRo · 12 Apr 2023 at 18:56

Rroff said:
Was meaning the vehicle battery - if you connect something like a booster converter up it won't have any protection against flattening the vehicle battery and potentially damaging it.

You are supposed to removed it after using otherwise as you said it is gonna drain the battery same with if the headlights are left on.

AtaRo · 12 Apr 2023 at 19:03

jigger said:
Hence why I said wiring is direct to the battery is a no no. It’s a terrible idea for lots of reason.

It is not supposed to wired directly to the battery, the 12V accessory outlet can be used.
I did not say wire it directly to the battery, you are the one implying wiring it to the battery directly.

jigger · 12 Apr 2023 at 19:05

AtaRo said:
It is not supposed to wired directly to the battery, the 12V accessory outlet can be used.
I did not say wire it directly to the battery, you are the one implying wiring it to the battery directly.

Wire the boost/buck converter?

AtaRo · 12 Apr 2023 at 19:30

jigger said:
Wire the boost/buck converter?

What are you referring to? You mentioned it several times.

jigger · 12 Apr 2023 at 20:24

AtaRo said:
What are you referring to? You mentioned it several times.

Wiring the boost converter is only one issue. Other challenges aside, what are you planning to do with the 19v DC output? Cut the jack off the power supply and plug straight into the laptop?

AtaRo · 12 Apr 2023 at 21:09

jigger said:
Wiring the boost converter is only one issue. Other challenges aside, what are you planning to do with the 19v DC output? Cut the jack off the power supply and plug straight into the laptop?

Getting a compatible adapter and using its jack.
Then set converter current output to match the adapter so it can be plug to the laptop.

jigger · 12 Apr 2023 at 21:21

AtaRo said:
Getting a compatible adapter and using its jack.
Then set converter current output to match the adapter so it can be plug to the laptop.

Driving the laptop direct at constant current/voltage? No thank you.

Chinese products like this have a place. It’s not in a wagon powering expensive electronics though.

Rroff · 12 Apr 2023 at 21:31

jigger said:
Driving the laptop direct at constant current/voltage? No thank you.

Chinese products like this have a place. It’s not in a wagon powering expensive electronics though.

Depends on the laptop - you get anything from simple 2 wire DC supply through to like 5-6 wires with negotiation/monitoring or a separate charging supply, etc. (or in the case of some high-spec laptops the second supply is dedicated to the GPU or second GPU).

jigger · 12 Apr 2023 at 21:44

Rroff said:
Depends on the laptop - you get anything from simple 2 wire DC supply through to like 5-6 wires with negotiation/monitoring or a separate charging supply, etc. (or in the case of some high-spec laptops the second supply is dedicated to the GPU or second GPU).

Depends on many things… Fill your boots chaps, just try it with your own kit first?

AtaRo · 13 Apr 2023 at 12:36

jigger said:
Driving the laptop direct at constant current/voltage? No thank you.

Chinese products like this have a place. It’s not in a wagon powering expensive electronics though.

Current pull will be determined by the laptop charging circuit and not by the converter.

jigger · 13 Apr 2023 at 12:56

AtaRo said:
Current pull will be determined by the laptop charging circuit and not by the converter.

Try it AtoRo. Capture the install and testing on dash cam.

AtaRo · 13 Apr 2023 at 13:13

jigger said:
Try it AtoRo. Capture the install and testing on dash cam.

Current will be determined by the load and not by the power supply current rating , I =V/R.

jigger · 13 Apr 2023 at 13:15

AtaRo said:
Current will be determined by the load and not by the power supply current rating , I =V/R.

Will it? Try it my guy.

Rroff · 13 Apr 2023 at 13:35

Unless into ultra high voltage breakdown territory the current flow will be the product of impedance as per above.

jigger · 13 Apr 2023 at 14:53

Rroff said:
Unless into ultra high voltage breakdown territory the current flow will be the product of impedance as per above.

You are quoting theory and recklessly ignoring the potential dangers here.

I don’t know what part of the system is designed to do what in this particular laptop.

What I do know is this is a dodgy AF solution and the generalisations and assumptions being present are dangerous. You chaps seem to know just about enough to get into real trouble TBH.

Rroff · 13 Apr 2023 at 15:09

jigger said:
You are quoting theory and recklessly ignoring the potential dangers here.

I don’t know what part of the system is designed to do what in this particular laptop.

What I do know is this is a dodgy AF solution and the generalisations and assumptions being present are dangerous. You chaps seem to know just about enough to get into real trouble TBH.

I've mentioned the potential dangers in a previous post. The detail comes down to what the actual power supply does functionally - if it is just a simple 2 wire DC connection then there is no specific problem to just plugging it in like this at the correct voltage (sure in a fault condition you've got a potential high current source in the equation hence I don't recommend it).

As before I don't actually recommend this approach but most laptop "chargers" don't actually function as a charger themselves which is where you'd have the most problem with simply wiring in to a boost converter.

EDIT: And it isn't like charging NiMH, etc. where at its most simplistic you have a current limiter inline with the battery.

jigger · 13 Apr 2023 at 15:33

Rroff said:
I've mentioned the potential dangers in a previous post. The detail comes down to what the actual power supply does functionally - if it is just a simple 2 wire DC connection then there is no specific problem to just plugging it in like this at the correct voltage.

As before I don't actually recommend this approach but most laptop "chargers" don't actually function as a charger themselves which is where you'd have the most problem with simply wiring in to a boost converter.

A boost converter, even a high quality one is not a suitable supply for any laptop. It’s a very dodgy idea for many reasons with 2 or 12 wires.

You have no idea how laptop charging systems have been implemented, so it’s probably best to stop with the generalisation and assumptions now.

Rroff · 13 Apr 2023 at 15:40

jigger said:
A boost converter, even a high quality one is not a suitable supply for any laptop. It’s a very dodgy idea for many reasons with 2 or 12 wires.

You have no idea how laptop charging systems have been implemented, so it’s probably best to stop with the generalisation and assumptions now.

As I mentioned there are a range of approaches used - at their most basic they don't have a control return and are just a dumb regulated supply, then you get varying degrees of complexity from there.

I do power supply (usually for small audio projects) design for a hobby.

jigger · 13 Apr 2023 at 15:44

Rroff said:
As I mentioned there are a range of approaches used - at their most basic they don't have a control return and are just a dumb regulated supply, then you get varying degrees of complexity from there.

I do power supply (usually for small audio projects) design for a hobby.

Yet you seem to have a very loose understanding of the topic.

I wouldn’t trust you with my small audio projects.