Charging laptop on boat

dukeofted said:
The USB charger I posted up will work with pretty much any laptop that charges using USB C. It outputs 20v and 90W. Most laptops outside of gaming and CAD don't use anywhere near that. The mains charger that came with the laptop is rated 20v and 130W.
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Lenovo 65W USB-C DC Travel Adapter
This is the one I use for my Ideapad 5i Pro and Lenovo are showing it at 50% discount.
 
Just to confirm that I've been using 12v USB-C chargers with my MacBooks for years now - now on my 3rd laptop charged this way (M2 Air).

Having killed a previous MacBook by charging it through a cheap USB-C hub I will now recommend only Belkin's USB-C chargers, as they offer a connected equipment warranty (or did last time I checked).

I think I'm using this 27W charger at the moment, but I have this one at the chart table too - even though it's only 15W, it's still enough to charge the laptop or keep it at 100% - doing some photoshopping a couple of years ago I managed to draw enough that it hovered between 90% and 100% for duration, but these laptops draw surprisingly little and it's wrong to think you need a 65W PSU.
 
KompetentKrew said:
You can charge then with a regular USB-C cable - it's not necessary to use the MagSafe port.
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Yes, but then you lose the benefit of it not been dragged off the chart table when somebody is careless 🤦‍♂️

As it comes with the right cable you might as well use it ;)

KompetentKrew said:
I think I'm using this 27W charger at the moment,
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That's the one we use.
 
dolabriform said:
Yes, but then you lose the benefit of it not been dragged off the chart table when somebody is careless 🤦‍♂️

As it comes with the right cable you might as well use it ;)



That's the one we use.
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Earlier you said just plug into a standard 12v socket, a certain person picked up on this and interpreted that as feeding 12v to the laptop.

What you are actually using is A USB-C PD charger, this communicates with your laptop to be able to fast charge it (but you already know that). ;)
 
PaulRainbow said:
Earlier you said just plug into a standard 12v socket, a certain person picked up on this and interpreted that as feeding 12v to the laptop.

What you are actually using is A USB-C PD charger, this communicates with your laptop to be able to fast charge it (but you already know that). ;)
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Hi Paul, what I said was ...

"I have a belkin 12v charger for my Macbook Pro, just plugs into a normal cigarette lighter socket."

edit:
apologies, my other reply was in reply to your suggestion that it will need a smart charger and won't work off 12v. I can see how that could be misconstrued.

The OP is asking about a MacBook Air, which will work with a USB-C cigarette lighter adaptor that many of us have mentioned. All the Apple kit has the charging electronics built into the device.

Why any manufacturer would think it a good idea to put the charge management system into an external block is beyond all logic to me, but that's another discussion.
 
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dolabriform said:
Why any manufacturer would think it a good idea to put the charge management system into an external block is beyond all logic to me, but that's another discussion.
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Standard USB is 5V. USB-PD uses various higher voltages to supply more watts over the cable without increasing the amps since the cables can't handle higher amps. This necessitates having some smarts at the supply end in order to negotiate with the device. The cable can also make a difference, with some limited to lower amps, and the whole system needs to negotiate up to its capability.
As I said earlier though, "USB-PD" supplies running from 12V are limited in what they can achieve without being quite large, and most will run 5V and max out the amps they deliver on each port rather than being true PD supplies. Some add a 9V capability but I've not seen any doing 15V or 20V. Assuming the maximum 5A delivery this gives you a theoretical 45W charge at 9V which will charge most laptops under normal conditions, but most will run closer to 2-3A to keep costs down. This still gives 18W in many 12V USB-C sockets, which is enough to keep the device charged under light use.
 
lustyd said:
Standard USB is 5V. USB-PD uses various higher voltages to supply more watts over the cable without increasing the amps since the cables can't handle higher amps. This necessitates having some smarts at the supply end in order to negotiate with the device. The cable can also make a difference, with some limited to lower amps, and the whole system needs to negotiate up to its capability.
As I said earlier though, "USB-PD" supplies running from 12V are limited in what they can achieve without being quite large, and most will run 5V and max out the amps they deliver on each port rather than being true PD supplies. Some add a 9V capability but I've not seen any doing 15V or 20V. Assuming the maximum 5A delivery this gives you a theoretical 45W charge at 9V which will charge most laptops under normal conditions, but most will run closer to 2-3A to keep costs down. This still gives 18W in many 12V USB-C sockets, which is enough to keep the device charged under light use.
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lustyd said:
Standard USB is 5V. USB-PD uses various higher voltages to supply more watts over the cable without increasing the amps since the cables can't handle higher amps. This necessitates having some smarts at the supply end in order to negotiate with the device. The cable can also make a difference, with some limited to lower amps, and the whole system needs to negotiate up to its capability.
As I said earlier though, "USB-PD" supplies running from 12V are limited in what they can achieve without being quite large, and most will run 5V and max out the amps they deliver on each port rather than being true PD supplies. Some add a 9V capability but I've not seen any doing 15V or 20V. Assuming the maximum 5A delivery this gives you a theoretical 45W charge at 9V which will charge most laptops under normal conditions, but most will run closer to 2-3A to keep costs down. This still gives 18W in many 12V USB-C sockets, which is enough to keep the device charged under light use.
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This why the Lenovo (and I believe some others) supply the USB PD charger in a small brick rather than a simple self contained plug-in type.
 
eddystone said:
I think I’ll wait till I get the laptop and see what it comes with. Tho only thing I’m certain of is that a 12v charger is a lot cheaper than replacing my modified sine wave inverter with a pure sine wave one.
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The short version of what I was saying is that the M2 Air will be fine with a 12V PD socket installed on the boat as long as you're not doing complex stuff like gaming or rendering movies. Something like https://www.amazon.co.uk/Socket-Waterproof-Charger-Delivery-Motorcycle/dp/B07NV6XT41 will work I'd expect. Bear in mind the lights on it are quite bright, the only one I found without lights was £50!
 
lustyd said:
The short version of what I was saying is that the M2 Air will be fine with a 12V PD socket installed on the boat as long as you're not doing complex stuff like gaming or rendering movies. Something like https://www.amazon.co.uk/Socket-Waterproof-Charger-Delivery-Motorcycle/dp/B07NV6XT41 will work I'd expect. Bear in mind the lights on it are quite bright, the only one I found without lights was £50!
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The performance of USB C sockets is advancing very rapidly. The socket in the link is only capable of delivering 1.5A at 12v or 18w.

There are much better models available if you require a high power delivery. For example, the unit in the link below is a reasonable price and will deliver 3.25A at 20v or 65w:

https://www.amazon.com/83W-12V-Outlet-Laptop-Charger/dp/B0B1DHNLDS

Some of the latest units conforming to higher PD 3.1 specification are capable of delivering 140w or more (the specification supports up to 240w), but these are expensive or difficult to find at the moment with a 12v input.
 
eddystone said:
But I will be processing and editing large image files in power hungry software like DXO Lab
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How long does the laptop battery last under those conditions and what power rating is the laptop power supply? That socket will most likely work ok depending on the laptop model.
 
eddystone said:
But I will be processing and editing large image files in power hungry software like DXO Lab
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Unless you’re doing a lot of them you’ll be fine. The actual processing won’t go on long with photos whereas video will slam the processor for quite a while. The M2 chip is pretty efficient too
 
eddystone said:
But I will be processing and editing large image files in power hungry software like DXO Lab
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How big are the files? Are you sure you need an M2 for that ??

Edit:
I've just looked at the price difference, seems stupid not to get a M2 🤪

I presume you're tripping it out with RAM? One thing I would recommend is to put your scratch disks and files on an external SSD and backup everything with something like Backblaze.
We have seen some pretty catastrophic internal SSD failures due to constant scratch / temp file access.
 
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dolabriform said:
How big are the files? Are you sure you need an M2 for that ??

Edit:
I've just looked at the price difference, seems stupid not to get a M2 🤪

I presume you're tripping it out with RAM? One thing I would recommend is to put your scratch disks and files on an external SSD and backup everything with something like Backblaze.
We have seen some pretty catastrophic internal SSD failures due to constant scratch / temp file access.
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50MB high resolution files on OM1 need some horsepower. Will only spec up SSD to 512 and graphics to 10 core, leaving RAM at 8gb. I can easily take an external SSD. Will be interesting to see how that performs compared to my i7 iMac with 32gb Ram
 
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