Charging laptop on boat

Been running computers on boats for years ....

The brick that sits between mains and the actual computer is just a regulated converter. The voltage / watts it supplies is actually what Computer needs to do 3 things : 1. run the computer, 2. Charge the battery, 3. power any additional such as USB items / DVD drives / external drives etc. plugged in and add to the computers power draw.

Most computers are happy with straight 12v actually and is what I give a few I have who's batterys died ... but they struggle to then power any additions plugged in.
So the DC - DC adaptor is the answer ... make sure the WATTS it can supply is same or greater than the original power supply you have.

Sadly one or two manufacturers do not like to lose money - so they add a third pin to the computer power plug ... then you have to buy from them ...

Generic DC - DC converters are fine ... no need to bust the pocket book on just a name brand ...
Sorry, but this is out of date. Modern laptops and many tablets need "smart" chargers to charge the battery, My Dell laptop charger output up to 20v. Generic chargers don't properly charge the batteries because there is no "communication" between the laptop and charger. DC-DC chargers won't work and i've tried generic chargers, that also don't work properly. Unfortunately for me, my models of laptop have no available DC charger, so have to be charged from mains/inverter.
 
Last edited:
On the plus side - many TVs and monitors take DC-DC converters happily. Our wifi router runs on straight 12v (I should probably convert that too for protection but it worked on test). Just need the inverter for higher powered modern laptops. Older or Chromebook type things probably fine (lower wattage non-smart charging).
 
I have one of the latest Lenovo's I am typing on now ... works fine of DC - DC ... (edit) I have just brought the new boat across Baltic with that Lenovo on a DC-DC brick !!

I also have ACER - same works fine.

Toshiba, HP and DELL are the piggies ... but Tosh is usually ok now - as is my TOSH ....

I have a whole stack of notebook PC's from my ex inspectors.... as well as my own upgrades.

We use :
Toshiba
Asus
Acer
Lenovo

mainly and stay clear of HP


I agree about some have smart battery management but your post is a little too wide in its condemnation. If people want to use Macs .. iPads etc .. then they pay the price of such decision.
 
20V 15V 12V 5V USB-C Car Charger Power Supply Adapter for Macbook Laptop Phone | eBay

I have used it a couple of times to charge my work laptop on the boat and it seems to work ok. It is a high spec CAD machine so on the more power hungry end of the scale so actually 90W isn't enough when doing more heavy duty work. By on average it does keep up and the laptop ends up remaining fully charged at the end of the day. I have USB C sockets on the boat and they are enough to trickle charge the laptop when it is off or on standby but as they are 5V only they won't come close to providing enough power to charge when using the laptop. Great for fast charging phones and tablets though.
 
Sorry, but this is out of date. Modern laptops and many tablets need "smart" chargers to charge the battery, My Dell laptop charger output 20v if connected to the correct charger. Generic chargers don't properly charge the batteries because there is no "communication" between the laptop and charger. DC-DC chargers won't work and i've tried generic chargers, that also don't work properly. Unfortunately for me, my models of laptop have no available DC charger, so have to be charged from mains/inverter.

Hi Paul, the OP is talking about Apple Laptops. Apple tablets do not need smart chargers. Apple laptops do not need smart chargers.
They will charge from a decent 12v Cigarette lighter socket without issues. I would recommend using genuine Apple or Belkin cables though ( just for the quality aspect ) as I've had issues with cheaper cables.

Both our MacBook Pros charge perfectly from the onboard supply, or from the car.
 
Sorry, but this is out of date. Modern laptops and many tablets need "smart" chargers to charge the battery, My Dell laptop charger output up to 20v. Generic chargers don't properly charge the batteries because there is no "communication" between the laptop and charger. DC-DC chargers won't work and i've tried generic chargers, that also don't work properly. Unfortunately for me, my models of laptop have no available DC charger, so have to be charged from mains/inverter.
They usually will charge just very slowly compared to their potential. I find it’s best to just use the laptop plugged in and it won’t discharge rather than try to later charge it. Overnight will usually bring the battery up though.
 
I have one of the latest Lenovo's I am typing on now ... works fine of DC - DC ... (edit) I have just brought the new boat across Baltic with that Lenovo on a DC-DC brick !!

I also have ACER - same works fine.

Toshiba, HP and DELL are the piggies ... but Tosh is usually ok now - as is my TOSH ....

I have a whole stack of notebook PC's from my ex inspectors.... as well as my own upgrades.

We use :
Toshiba
Asus
Acer
Lenovo

mainly and stay clear of HP


I agree about some have smart battery management but your post is a little too wide in its condemnation. If people want to use Macs .. iPads etc .. then they pay the price of such decision.
But the OP is buying a new Mac, needs a smart charger to work at it's best.

You cannot charge a 19v battery from 12v.

Of course, there are models that will work from a DC charger, my Dell Latitude works fine from the official Dell charger. I have 2 Dell Inspirons and they don't charge properly from a DC-DC converter and certainly won't charge from a 12v supply as the batteries are 19v

If you have a modern Lenovo tablet, it uses a mains smart charger. If you're charging from a straight DC-DC converter it will work but at a slower charge rate. If that's ok for you, that's fine.

But, don't forget what the OP is buying.
 
I have used dell PC's on the boat.
The modern ones have a clever charger which talks to the PC.
The older ones just delivered 19V DC.

However, I find that even on a so called 200W sine wave converter, that a 90W charger for a PC can sometimes be at the limit as to what the DC-AC converter can supply.

A lot of the specifications on DC to AC converters have no resemblance to what the converter can do.
For instance you can find a lot of small 500W converters which come with a cigar lighter plug to connect to the 12V.
Cigar lighter plugs are often fused to 8A to stop the plug melting.

500W? Pull the other one.

I.e. to recharge a PC, you need a decent sine wave converter and DC supply and wiring hook up for it.

NB I suspect that my sine wave converter does not generate sine waves.
I have killed several electric tooth brush charges on the boat. I have never killed one on lamd.
 
High power USB C 12v chargers are readily available. These are smart chargers, or more correctly smart power delivery systems (the charging is controlled by the laptop). They use the standard PD (Power Delivery) protocol that Apple uses so will negotiate with the laptop to deliver up to 20v.

The example below will supply 60w, but higher power units are available if needed. They are available to plug into a cigarette lighter socket or wired directly into 12v.



https://www.amazon.co.uk/Charger-Cigarette-Lighter-Adapter-Recorder-Black/dp/B08ZXN9LYP/ref=sr_1_8?crid=1UFMM6Y63S5VI&keywords=Usb+c+charger+12v+high+power&qid=1689603587&quartzVehicle=29-10519&replacementKeywords=usb+c+12v+high+power&sprefix=usb+c+charger+12v+high+power,aps,466&sr=8-8
 
Last edited:
To clarify my post above, my laptop is a fairly recent Dell and charges fine with the charger I posted above. It doesn't quite keep up when doing taxing stuff by when doing general office tasks it is more than fine. I find the battery slowly drains when intensively using taxing software (although slower than when not plugged in) and then starts to add charge to the batteries in normal use.
 
But the OP is buying a new Mac, needs a smart charger to work at it's best.

You cannot charge a 19v battery from 12v.

Of course, there are models that will work from a DC charger, my Dell Latitude works fine from the official Dell charger. I have 2 Dell Inspirons and they don't charge properly from a DC-DC converter and certainly won't charge from a 12v supply as the batteries are 19v

If you have a modern Lenovo tablet, it uses a mains smart charger. If you're charging from a straight DC-DC converter it will work but at a slower charge rate. If that's ok for you, that's fine.

But, don't forget what the OP is buying.
I read what he's buying and you haven't read others replies ..

Sorry but I disagree with you and that's that. Seems others do as well.
 
I am on my third after market power supply for my Lenovo Laptop

The issue I have has is the wire breaking at the power connector.

The after market cones with several different Laptop power connectors for different manufacturers of Laptop

Laptop manufacturers try to have unique commixture and / or Voltages or power protocols to try to reduce the supply of third party power supplies
 
High power USB C 12v chargers are readily available. These are smart chargers. They use the standard PD (Power Delivery) protocol that Apple uses so will negotiate with the laptop to deliver up to 20v.

The example below will supply 60w, but higher power units are available if needed. They are available to plug into a cigarette lighter socket or wired directly into 12v.



https://www.amazon.co.uk/Charger-Cigarette-Lighter-Adapter-Recorder-Black/dp/B08ZXN9LYP/ref=sr_1_8?crid=1UFMM6Y63S5VI&keywords=Usb+c+charger+12v+high+power&qid=1689603587&quartzVehicle=29-10519&replacementKeywords=usb+c+12v+high+power&sprefix=usb+c+charger+12v+high+power,aps,466&sr=8-8
And they work also for my Lenovo Ideapad which needs a PD charger.
 
I have used dell PC's on the boat.
The modern ones have a clever charger which talks to the PC.
The older ones just delivered 19V DC.

However, I find that even on a so called 200W sine wave converter, that a 90W charger for a PC can sometimes be at the limit as to what the DC-AC converter can supply.

A lot of the specifications on DC to AC converters have no resemblance to what the converter can do.
For instance you can find a lot of small 500W converters which come with a cigar lighter plug to connect to the 12V.
Cigar lighter plugs are often fused to 8A to stop the plug melting.

500W? Pull the other one.

I.e. to recharge a PC, you need a decent sine wave converter and DC supply and wiring hook up for it.

NB I suspect that my sine wave converter does not generate sine waves.
I have killed several electric tooth brush charges on the boat. I have never killed one on lamd.

Ahhh ... now you have hit the nail on the head ... the form of power delivery from an inverter. It can be square wave - many regulated power supplies HATE that and default out. Pure sine wave is more expensive and will usually work as long as the mean value is sufficient.

I mentioned my latest Lenovo running of a standard DC-DC computer power supply .... it also actually runs of the cheap 150W inverter I carry as back-up .......
My old Tosh used to dislike that inverter as it used a small amount of battery along with inverters power ... so about 12hrs later it would die !! DC-DC unit was similar story .... but pull battery out ... isolate terminals - put back to balance the computer ... plug in 12v direct .... ran fine. As do my Acer ONE .... Asus .... Acer etc.
12v is more than enough to run the computer as it steps that down to 5v on older and 3.3v on later boards ... the extra voltage provided by mains charger is to charge battery overhead.
 
I read what he's buying and you haven't read others replies ..

Sorry but I disagree with you and that's that. Seems others do as well.
I know what he's buying and it has, by default, a smart charger.

Someone has said they use a non-standard charger and it works. It actually works up to a point, see post #30

Not everyone uses either cheap, or old equipment and not everyone is happy with sub standard methods.
 
I know what he's buying and it has, by default, a smart charger.

Someone has said they use a non-standard charger and it works. It actually works up to a point, see post #30

Not everyone uses either cheap, or old equipment and not everyone is happy with sub standard methods.

I decided to delete appropriate reply.
 
Hi Paul, the OP is talking about Apple Laptops. Apple tablets do not need smart chargers. Apple laptops do not need smart chargers.
They will charge from a decent 12v Cigarette lighter socket without issues. I would recommend using genuine Apple or Belkin cables though ( just for the quality aspect ) as I've had issues with cheaper cables.

Both our MacBook Pros charge perfectly from the onboard supply, or from the car.
I take it you are using USB C Dave ?
 
Aftermarket (Amazon sourced) USB C 12v charger works fine for me on recent Lenovo Yoga, HP and Dell laptops (neither cheap or old)

Is slower to charge but just leave it plugged in...
 
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.
 
Top