Charging lap-top from cigarette lighter
Submitted: Monday, May 25, 2015 at 14:01
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Homebrewer
G'day all,
I am hoping to charge a lap-top from the cigarette lighter with a 90watt 19.5 volt car charger from Dick Smiths.
Is anyone using a car charger to charge their lap-top?
Has it been successful and does the car need to be running to charge?
Does it take any longer to charge using this method compared to the 240 volt charger?
Thanks in advance Pete.
Reply By: Racey - Monday, May 25, 2015 at 14:50
Monday, May 25, 2015 at 14:50
Have used this method regularly with no problems. Charge time is the same.
Cheers
Jon
AnswerID:
554203
Follow Up By: cruiser 3 - Monday, May 25, 2015 at 14:53
Monday, May 25, 2015 at 14:53
I agree with Racey. The car doesn't have to be running.
FollowupID:
840203
Follow Up By: TomH - Monday, May 25, 2015 at 15:09
Monday, May 25, 2015 at 15:09
It does if you dont want a flat battery eventually and most ciggy lighters only work with ignition on anyway
To OP see answers on Caravanners
forum fully answered there
FollowupID:
840206
Follow Up By: Batt's - Monday, May 25, 2015 at 16:32
Monday, May 25, 2015 at 16:32
My wifes car has 2 lighter sockets the 1 beside the driver's console I disconnected the wires and ran some 3 mm twin core wire to the battery and fitted a 5 amp fuse so she can charge her phone or ipad without disrupting it during charging which is better for the life of the battery and they don't draw enough power to flatten a car battery in a hurry. Just find out how much power your laptop draws or show it to an auto electrician he should be able to help you out.
FollowupID:
840218
Follow Up By: TomH - Monday, May 25, 2015 at 18:07
Monday, May 25, 2015 at 18:07
A reasonable sized laptop will draw up to 6 amps at 19 volts. I had a 3.5 amp supply and it wasnt big enough. Had to get a 6 amp 90W one.
An Ipad can charge on 5 v 2.5 amps
FollowupID:
840226
Follow Up By: Batt's - Tuesday, May 26, 2015 at 13:45
Tuesday, May 26, 2015 at 13:45
I did do some research last night before replying and there was a fellow who used a 120 amp hr battery fully charged it took 3 hrs to charge his laptop and the car battery had 82% charge left in it and yes that is bigger than the usual car battery but if your battery is in good condition I expect you should be able to at least charge it once without a problem depending on the size of the laptop and your battery that's why I would recommend getting an auto elec to do the sums first. Using a dual purpose battery could help in the long term I'll put one in my wife's car when the original battery packs it in that way I can throw the camping fridge in if we want it for overnight stops when we don't take the 4WD..
FollowupID:
840259
Follow Up By: cruiser 3 - Tuesday, May 26, 2015 at 15:24
Tuesday, May 26, 2015 at 15:24
I must be lucky then because I have been running my laptop, charging 2 iPhones and 2 Nikon camera batteries for more than 5 years on car battery, jump starter or aux 12 volt battery with no problems. Either of the batteries don't requre a lot of charge from the solar panels to bring them back to full charge.
I actually connect the laptop to one of the batteries when using it instead of charging it later (just my habit)
The laptop draw varies between 3 to 4 amps. My cig lighter socket has power when the key is on accessories.
FollowupID:
840270
Reply By: vk1dx - Monday, May 25, 2015 at 18:36
Monday, May 25, 2015 at 18:36
Takes about the same time. Got our charger from Ebay. No need for the car to be running either. The laptop was the last item that needed 240V. Now we don't even take the inverter and no need to even consider a generator.
Phil
AnswerID:
554216
Reply By: Member - Serendipity(WA) - Monday, May 25, 2015 at 18:54
Monday, May 25, 2015 at 18:54
I tried running my laptop from the Cigarette lighter when on a long trip years ago. Seem to work on the trip but when I got
home the laptop power pack was burnt out - probably from under supply of current. I was using a 150w 'pure sine wave' inverter.
Also tried an after market 12v plug direct to the laptop - burnt that out too. I think the laptop tried to pull too much power and it over heated the plug in the cigarette lighter and melted it. It is weird that the charger power pack on the laptop says 45w but I have been told it will draw a lot more than that. Not sure how this blue smoke trick works.
Now I have a 1500w 'pure sine wave' inverter that has 10mm cables no longer than 600mm direct to deep cycle batteries. Only problem is the touch mouse pad does not work with an ungrounded inverter connection meaning I can't use the laptop while charging. All is fine other wise.
Serendipity
AnswerID:
554217
Reply By: garrycol - Monday, May 25, 2015 at 20:48
Monday, May 25, 2015 at 20:48
I used a 12v power supply to run my Tosiba laptop no issues. Upgraded the Tosiba to a HP but couldn't use the power supply that I had as it did not have a HP plug. Last week I looked at 120w power supplies at Jaycar that did have a HP plug and these were about $80 up and could only he used to power laptops.
I ended up buying a 300/600w Pure Sine Wave inverter off ebay for $65. Will do the same job as as the 12v power supply but have a lot more uses so I consider a good alternative.
Garry
AnswerID:
554225
Follow Up By: garrycol - Wednesday, May 27, 2015 at 10:09
Wednesday, May 27, 2015 at 10:09
Thanks for those links.
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Reply By: Michael H9 - Tuesday, May 26, 2015 at 08:09
Tuesday, May 26, 2015 at 08:09
I use a Belkin multi plug adapter that runs off 240 volts or 12 volts. It came with the car lighter adapter and also has a usb port for charging other devices. I've never had a problem with it charging several different laptops, phones or tablets. I'd be wary of charging anything for too long with the motor off simply because it is running the car battery down.
AnswerID:
554236
Reply By: Sigmund - Tuesday, May 26, 2015 at 10:04
Tuesday, May 26, 2015 at 10:04
I found a 12v step-up transformer would charge the laptop batteries slowly with the engine off, more fully with the engine running.
The biggest hassle has been changing laptops and finding that the charging kit didn't have the right tip. Has happened twice. Beware of Asus Zenbooks; they have a rare socket that I could only hook up to by buying a cheap 240V charger from o/s and cannibilising the plug.
Inverters are an alternative but IMO standardising on 12v saves a lot of hassle.
AnswerID:
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Follow Up By: vk1dx - Tuesday, May 26, 2015 at 14:48
Tuesday, May 26, 2015 at 14:48
Sigmind. Q? Step up transformer for 12V. How does that work?
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840265
Follow Up By: Sigmund - Tuesday, May 26, 2015 at 16:58
Tuesday, May 26, 2015 at 16:58
Yeah. Some auto select the voltage.
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840281
Reply By: Peter - Wednesday, May 27, 2015 at 07:29
Wednesday, May 27, 2015 at 07:29
Hi Have been using 12 v chargers for a long time. I prefer to plug in when running truck to charge and then run off batteries when not ( This is good for batteries . They need to cycled)
I got
mine from here
http://www.laptop-charger.com.au/dell-laptop-car-adapter/
Had for 4 years no problems .
Also when changing laptops needed a different plug so went to
http://www.dx.com/ Deals extreme and found one for under $5.
Just be sure that you get Charger that meets output specs of AC charger.
AnswerID:
554290