Laptop power - 12v converter to 240V or to 19v 4.2ma?

[PhillM]

I have to do about 4 days work over the summer. It is fairly time critical, but I do not want to have to come home to do it so I plan to take my laptop with me but cannot guarantee to be in a place with mains power. I expect that I will need to charge it off the 12v system. I have a basic setup, engine battery, 110 AH domestic. One cig socket. Ability to croc clip to the batter of course. Battery charging is via the engine and a 75W solar panel. I don't mind if I have to be running the engine to charge, as its only for the occasional/emergency use (I do plan to be in a marina for works days, but with COVID, you never can tell).

So, would you buy

a) 12 v to 19v converter

b) 12v to 240v converter, then just plug in the std laptop power block?

Whatever I do it MUST work and I will have limited time to test prior to departure, so please only recommend from personal experience.

Thanks

 

[JumbleDuck]

I would buy a 12V supply - normally sold as car adaptors - and test it in my car beforehand.

I use an old IBM Thinkpad and a modern Dell Chromebook on board and both work perfectly with car chargers.

 

[bromleybysea]

I would buy a 12V supply - normally sold as car adaptors - and test it in my car beforehand.

I use an old IBM Thinkpad and a modern Dell Chromebook on board and both work perfectly with car chargers.

+1

 

[bromleybysea]

+1

Car adapters are polarity sensitive. Not a problem if you use the ciggie plug supplied, but if you wire it in.....

 

[prv]

Same as Jumbleduck - if there's a car adapter available for the laptop, I'd use that.

I don't normally take a laptop on the boat, only occasionally while I was troubleshooting instrument setups. But for that use, I have a car charger and it works fine.

If there isn't an off-the-shelf car charger, in your position I'd probably buy a small inverter rather than rely on a generic DC-DC. Laptop power bricks are often more than just a simple power supply.

Pete

 

[PhillM]

Thanks guys, there doesnt seem to be a branded one - Acer travelmate IP 648T.

If you went the 240 route, any recommendations?

 

[DJE]

I've used these people in the past.

The Web's Largest Supplier Of Laptop Power Adapters & Laptop Chargers | Power4Laptops

Search by make and model or tell them the voltage and current you need.

 

[pvb]

Car chargers work fine. No need for an inverter.

 

[sarabande]

If you buy a 12cDC to 240vAC inverter, say around 300W, you will have a AC source for other small devices needing domestic power. I suggest that you ensure it is a pure sine wave inverter to avoid any problems with devices sensitive to clipped or square output.

Modern ones now come with USB 1A and 2.1A sockets.

I have a Skytronic 150W for occasional use off farm vehicles, but a beefier one by ??? of 350W on the boat.

 

[oldmanofthehills]

Thanks guys, there doesnt seem to be a branded one - Acer travelmate IP 648T.

If you went the 240 route, any recommendations?

Inverters are inefficient, and to some extent so are chargers. Cut out the middleman if you can. You are not running power tools or heavy duty stuff as my son does from his van - and he definitely leaves engine running.

 

[Refueler]

DC to DC is way to go ..... ACER will accept generic ...

Inverters are really wasteful if only needed for a computer ... and then you need to make sure you get a good one with enough power (Watts) to do the job ...
You can get cheap 150W inverters that crap out just powering a computer ... I know - I have a couple !!

 

[JumbleDuck]

Thanks guys, there doesnt seem to be a branded one - Acer travelmate IP 648T.

Not Acer branded, but it looks as if the one would do: Power4Laptops DC Adapter Laptop Car Charger Compatible With Acer TravelMate P6: Amazon.co.uk: Computers & Accessories

If you went the 240 route, any recommendations?

Not a cheap "can holder" type. I have one and switched-mode power supplies like laptop chargers hate the waveform it puts out.[/QUOTE]

 

[Iliade]

I have an eBay 12v MacBook charger which has worked faultlessly for years.

Oh bu$$er that's blown it!

I previously used a 150W IIRC inverter to run the mains charger for an old Satellite Pro, but it would overheat the car 12v socket so I moved to DC-DC.

 

[michael_w]

Maplin used to sell a brilliant charger input ac/dc from shore power/aircraft/ motor/boat etc. Output in selectable voltages, umpteen connectors and it could do your phone at the same time. Sorry mine's not for sale

 

[Refueler]

I have an eBay 12v MacBook charger which has worked faultlessly for years.

Oh bu$$er that's blown it!

I previously used a 150W IIRC inverter to run the mains charger for an old Satellite Pro, but it would overheat the car 12v socket so I moved to DC-DC.

No surprise ... a car socket is not supposed to go more than 10A max ... that's 120W at the plug ... a 150W inverter will probably be pulling 170W ...... anywhere up to about 14A ...... most car sockets are fused at 10 - 15A ...

 

[Iliade]

Sort of - The inverter will pull watt (!) the charger demands, plus the inverter's losses, up to the maximum consumption of the inverter, then it should trip.

The trouble is that the mains charger is a switched-mode power supply, which causes the switched-mode inverter to get all hot under the collar and draw a lot more power than it chooses to pump out, creating waste heat in the process.
A quick google reveals that Sat Pro mains chargers can be 65 W, which 'should' be easily capable of being run from a 12V socket at about 6A, but evidently aren't appropriate for continuous use.
The subsequent 12V - 19V charger worked fine.

 

[Zing]

Go for option (a). That’s what I did. Efficient and cheap. Tons of D.C. converters on fleabay.

 

[colind3782]

I have a 12v > 19v adapter for an Acer that I never use but, of course, it's on the boat in Spain! They're cheap enough on ebay etc.

 

[Refueler]

Sort of - The inverter will pull watt (!) the charger demands, plus the inverter's losses, up to the maximum consumption of the inverter, then it should trip.

The trouble is that the mains charger is a switched-mode power supply, which causes the switched-mode inverter to get all hot under the collar and draw a lot more power than it chooses to pump out, creating waste heat in the process.
A quick google reveals that Sat Pro mains chargers can be 65 W, which 'should' be easily capable of being run from a 12V socket at about 6A, but evidently aren't appropriate for continuous use.
The subsequent 12V - 19V charger worked fine.

Yes - but trouble is the power supply to the computer is doing two jobs and one of them can push the 'brick' into the high wattage numbers ..... charging the computers battery.

That's why I used to run my computer on board without the battery .... and as few peripherals connected as well.

 

[oldgit]

Have used a 12V to 19V adaptor to run an ancient laptop with Seaclear Nav software on my Mobo. (VMH)
Tip buy the best quality one you can afford.
A second hand original one is probably better than a cheapy clone.
In my system the adaptor will be running all the time, which could be up to 10 hours .
Ps. We do have the battery and charging capacity on boat to not even notice this currant drain.
The laptop battery remains insitu allowing about 60 mins battery back up power.