Charge Laptop directly with DC?

DangerousPirate

DangerousPirate

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I was thinking if I plug my laptop directly into DC with a dc-dc step up converter, I'd save a significant amount of power. Has anyone done that? Are the savings enough? I feel like using an adapter and an inverter just eats a lot of power. The same way how using a plug to charge your phone is losing power by the internal conversion, while plugging it directly into the usb port is better.


My biggest issue is, that I can't find the right dc-dc step up converter. I need 20v exactly, and can't do with the 24v models.
 
DangerousPirate said:
I was thinking if I plug my laptop directly into DC with a dc-dc step up converter, I'd save a significant amount of power. Has anyone done that? Are the savings enough? I feel like using an adapter and an inverter just eats a lot of power. The same way how using a plug to charge your phone is losing power by the internal conversion, while plugging it directly into the usb port is better.


My biggest issue is, that I can't find the right dc-dc step up converter. I need 20v exactly, and can't do with the 24v models.
Click to expand...
I have a Dell laptop and was able to buy on their website a charger/power supply that plugs into a standard 12v car/cigarette lighter type socket on the boat. It seems to work very well and appears to be good quality. I saw cheaper ones on Amazon, which might be fine too, but decided to pay the extra and buy from Dell.
I’d guess similar are available for other makes.
 
richard77777 said:
I have a Dell laptop and was able to buy on their website a charger/power supply that plugs into a standard 12v car/cigarette lighter type socket on the boat. It seems to work very well and appears to be good quality. I saw cheaper ones on Amazon, which might be fine too, but decided to pay the extra and buy from Dell.
I’d guess similar are available for other makes.
Click to expand...
Not for my laptop, I have already checked. It's a powerhungry little one, but sometimes I need that extra power for work. I had looked into car chargers, they made quite a few. They just don't make them in my requirements, or at least I haven't seen any.

My current adapter for the laptop is 200w, with 10a and 20v
 
DangerousPirate said:
Not for my laptop, I have already checked. It's a powerhungry little one, but sometimes I need that extra power for work. I had looked into car chargers, they made quite a few. They just don't make them in my requirements, or at least I haven't seen any.

My current adapter for the laptop is 200w, with 10a and 20v
Click to expand...
Would be useful to know what laptop it is.
 
Best practice would be to use a car adapter made for your laptop, ideally by the maker of your laptop. Plug it into a lighter socket.
 
Dockhead said:
Best practice would be to use a car adapter made for your laptop, ideally by the maker of your laptop. Plug it into a lighter socket.
Click to expand...
I mean, I tried to find one but was not successful. Not for the required output.

Laptop's an Asus Tuf A15


1747938575990.png
I have found this plug, and I was thinking of a DC-DC inverter like this:

1747938629608.png

It's just that I don't find the correct step up converter to match my requirements. Or maybe I got something wrong in my specs. Not sure.
 
How about this one?
Ali Express
DC DC 12V to 20V Step-up Power 15A 20A 25A 30A Boost Converter Voltage Stabilizer Regulator CE ROHS for Cars Solar
4 versions, all 12- 16v DC input voltage, all 20v DC output voltage, option of 15amp, 20amp,25amp and 30amp output current

DC DC 12V bis 20V Step-up Power 15A 20A 25A 30A Boost Converter Spannungsstabilisator Regler CE ROHS für Autos Solar - AliExpress 13

£20.09 plus shipping £18.04, delivery 1st July to 7th July

Designed for solar charging, but the wide input voltage range would work on a boat.
 
Laser310 said:
that's the adapter...

but what are the actual requirements for the laptop?

is it really 200W?
Click to expand...
I mean, at least 150w, the adapter is 200w. But important is the 20v and 10a
PaulRainbow said:
Pardon our interruption...
Click to expand...
Thanks Paul, that looks quite good. Bit expensive, but exactly what I'd need.
Boater Sam said:
Easy fix, ebay have the 12v adaptors See Pardon our interruption...

You don't need a 200w adaptor, this one is for your computer.
Click to expand...
Don't need an AC one (already have that). I am looking to connect dc to dc with a step up.
Ian_Edwards said:
How about this one?
Ali Express
DC DC 12V to 20V Step-up Power 15A 20A 25A 30A Boost Converter Voltage Stabilizer Regulator CE ROHS for Cars Solar
4 versions, all 12- 16v DC input voltage, all 20v DC output voltage, option of 15amp, 20amp,25amp and 30amp output current

DC DC 12V bis 20V Step-up Power 15A 20A 25A 30A Boost Converter Spannungsstabilisator Regler CE ROHS für Autos Solar - AliExpress 13

£20.09 plus shipping £18.04, delivery 1st July to 7th July

Designed for solar charging, but the wide input voltage range would work on a boat.
Click to expand...
That looks very good, too. So either yours or pauls, pauls is more expensive but looks more solid. Yours is cheaper. I think I'll go with the aliexpress one first and see if my boat burns down. If it does - I'll buy a new boat and try again with Paul's :P

Thanks for the help. I hope it'll save me some juice. I work as a digital nomad, and I am looking at wys to reduce my power consumption. But fridge + Laptop + Starlink = ⚡⚡⚡

Hoping a different router for starlink (dc one) and putting the laptop on DC directly will cut my power costs down significantly. Getting ready for the sun!
 
DangerousPirate said:
Hoping a different router for starlink (dc one) and putting the laptop on DC directly will cut my power costs
Click to expand...
Spoiler alert - no, not really. It does save some but these are heavy usage items and saving 1% changes very little. I did all of it, you can find the threads.
In case you’re curious, Eberspachers suck power faster than fridges too!
 
DangerousPirate said:
I mean, at least 150w, the adapter is 200w. But important is the 20v and 10a

Thanks Paul, that looks quite good. Bit expensive, but exactly what I'd need.

Don't need an AC one (already have that). I am looking to connect dc to dc with a step up.

That looks very good, too. So either yours or pauls, pauls is more expensive but looks more solid. Yours is cheaper. I think I'll go with the aliexpress one first and see if my boat burns down. If it does - I'll buy a new boat and try again with Paul's :p

Thanks for the help. I hope it'll save me some juice. I work as a digital nomad, and I am looking at wys to reduce my power consumption. But fridge + Laptop + Starlink = ⚡⚡⚡

Hoping a different router for starlink (dc one) and putting the laptop on DC directly will cut my power costs down significantly. Getting ready for the sun!
Click to expand...
My boat came with a cheap Chinese DC-DC converter. It decided to fry my newly fitted £1000 black box VHF.

How much is your laptop worth ?
 
lustyd said:
Spoiler alert - no, not really. It does save some but these are heavy usage items and saving 1% changes very little. I did all of it, you can find the threads.
In case you’re curious, Eberspachers suck power faster than fridges too!
Click to expand...
In terms of efficiency, an inverter is going to be about 90% efficient, DC-DC converter and the 240VAC charger about the same. So using an inverter will be something like 10% less efficient then a DC-DC converter. 10% of not a lot isn't too much. But the big loss with the inverter is the typical 0.5A overhead when the inverter isn't doing anything.
 
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