# 12v laptop charger connected to leisure battery



## yandoo (May 10, 2012)

Hi there I recently installed a 12v cigarette car socket to my leisure battery and bought a 12v laptop charger. It doesn't work, only charges for 3 seconds and stops. I tested it in another car and had the same results until I started the engine when and then it works! I didn't realise it only works when the engine is on? 

My leisure battery is fairly new and I think around 85amp/hrs. 
Surely there must be a way to power a 12v laptop charger from a 12v cigarette socket connected to a leisure battery? If so how would I do that? i can always upgrade to 2 better batteries and so would have more then enough power. 

Please help 

Thank you


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## Bigpeetee (May 10, 2012)

Mine works all the time on my leisure batts.

Is it a type specific or a general purpose one?

Where did you get it from, can we see the type and model??

As much info as poss please, Laptop requirements, what the label says on the charger etc


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## Beemer (May 10, 2012)

I have a laptop charger too, the instructions state that the engine must be running for the charger to work.
I have two 115Ah leisure batts, and have found that the charger worked ok running from these.  I have not tested to see how long it would last, but plenty long enough to top up the laptop for an hour or so (so far).


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## bobowas007 (May 10, 2012)

*laptop charger*

go to maplins 12v 130w 12to24v output charger £35 works for me.


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## yandoo (May 10, 2012)

Thanks for the replies, 

I bought both of them from ebay; 12v cigarette socket and laptop 12v laptop charger

ACER ASPIRE 5730ZG 5739G 5742G 5710G 5720 LAPTOP 90W / 12V CAR ADAPTER CHARGER | eBay

12v Female Car Cigar Cigarette Lighter Socket Plug Connector High Quality 2M 5A | eBay

My laptop is an Acer Aspire 5720 and the mains adapter says output: 19v 3.24amps. 

What do ya think? 

Thank you


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## Canalsman (May 10, 2012)

The specification on the eBay link says minimum input voltage 11.5v ...

I'd suggest one of two things are causing the problem:

1) The leisure battery voltage is dropping below 11.5v when you plug the charger into the cigar lighter socket

or

2) There's a poor contact between the plug on the charger and the cigar lighter socket

If it's the first then your leisure battery is either pretty much flat, or it's knackered.

The second could be caused by a faulty plug or a faulty socket.

Given that you've tried it in two vehicles it's probably the second fault.


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## Somelier (May 10, 2012)

Have you used heavy duty cable and fuse between the lighter socket and the battery? I found that using a lightweight extension lead from the lighter socket to my inverter had exactly the same effect. When I plugged directly into the lighter socket, the inverter worked fine.


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## yandoo (May 10, 2012)

I did use the very small wires that came with the 12v socket, I also didn't use a fuse. I also measured the voltage of the leisure battery when dormant to be 12.70v, with a single 12v light on it measured 12.60v. I've not measured it with the laptop charger on yet but I have tested power is going to the cigarette socket ok. 

I'm not convinced its the small wires that came with it as I had the same results when I tested the laptop charger in another car. I thought the battery was fairly new, it looks it. 

Thanks ever so much for the help


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## Canalsman (May 10, 2012)

Just had a look at the socket you have bought.

It's rated at only 5 amps - the usual rating for these sockets is 10 amps, double what you have bought.

I think that's the cause of your problem. Try plugging the charger directly into a car's cigar lighter socket, which will be rated at 10 amps, and then try the laptop. If that works, without the engine running, then you need to buy another socket rated at 10 amps.


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## yandoo (May 10, 2012)

I tested it in another car and got the same results, unless the engine was running.


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## activecampers (May 11, 2012)

echo above.

You need a 10a socket, not 5A, though doubt this is your issue (though could be later on)

As mentioned get a Maplin 120W multi laptop charger.  Mine happily charges a Samsung netbook; Asus ULV laptop and a Dell XPS laptop from leisure batteries.  eBay electronics are iffy at best.

Also I do recommend you over spec your charger.  120W is fine for most normal latops, but don't get a 65W charger if thats all your laptop needs.  It will get hot and I've had one blow up   Get one that has more capacity than you need - it will run cooler and more efficiently (and doesn't draw the power unless you need it)


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## Bigpeetee (May 11, 2012)

I've got a similar one for my Compaq and works great.

If it doesn't work on your leisure batt or another car (unless the engine's running) it could be faulty.

Try it with the laptop batt is say 80% capacity, there's not so much of a load. It's possible that the socket won't take the load, but if your friends car heats up the ciggy lighter, then there's enough there.

If it still doesn't work return it, the ad says it's got a 6 month warranty.

Thank you


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## yandoo (May 11, 2012)

Hi all, thank you so very much for your advice and support with this. It was certainly making me itch my head but thank to you all there is a solution.

I spoke to the seller of the 12v laptop charger and he said it only works when engine is running (at that is normal?), which seems a bit pointless for camping. 

One thing that I find strange is that even when the leisure battery in my camper is being charged from the mains on-board charger (voltage of over 13v when measured) it still doesn't work? Yet when an engine is running it does, perhaps  when a battery is being charged from an alternator higher volts are measured on the battery?

I did another test today noting a minimal voltage drop when the 12v charger was connected from: 12.52v to 12.48v. I also tested turning on 12v lights one at a time noting <=1v drop per light. - Is that normal drain?


So I guess it looks like it should be working and so assume the problem is with the 12v laptop charger, perhaps there is some type of cut off built into it? 

I think ill buy a universal 12v charger from Maplins that has higher watt. My laptop only requires 90w which is what the ebay charger stated, so the extra oomph should help. Also I shall buy a new 10amp 12v cigarette socket.

I'll let you know how it goes. 

Thank you all very much, its nice to see a community of happy campers.


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## Firefox (May 11, 2012)

Some of this type of device don't work unless they have a higher voltage input from the alternator. They are really meant for execs who want to charge their phone or laptop on a business trip. I think it is a feature to safeguard flattening the the vehicle battery. Not much good for campers, but built for a different market I guess.


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## Bigpeetee (May 11, 2012)

yandoo said:


> I spoke to the seller of the 12v laptop charger and he said it only works when engine is running (at that is normal?), which seems a bit pointless for camping.



Don't let him fob you off as he's trying to do!!
Advert specified 11.5v upward operation, that's an almost totally flat battery.

Tell them you want a replacement as it's not working to their specification, or a total refund.

Use the Ebay messaging system so that all messages can be seen, I know it's not a huge amount of money, but things are tight these days AND a product should work to specification.

YOU ARE IN THE RIGHT

Have you given feedback yet?? If not, don't until it's resolved.


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## yandoo (May 11, 2012)

Bigpeetee said:


> Don't let him fob you off as he's trying to do!!
> Advert specified 11.5v upward operation, that's an almost totally flat battery.
> 
> Tell them you want a replacement as it's not working to their specification, or a total refund.
> ...



Haha you may be right. In fact I opened a case with the seller and got a replacement sent out already and then on further investigation and after speaking to the seller discovered it doesn't work unless the engine is running. I ask for a refund then based on the fact it says minimum output is 11.5v. 

thank you


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## Canalsman (May 11, 2012)

Bigpeetee said:


> Don't let him fob you off as he's trying to do!!
> Advert specified 11.5v upward operation, that's an almost totally flat battery.
> 
> Tell them you want a replacement as it's not working to their specification, or a total refund.
> ...



Agreed ... the charger is faulty.


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## yandoo (May 11, 2012)

Yay refund!

I just spoken to Maplins and Caracamp about their 12v laptop chargers and they both say it has to have the engine running on too?? WTF?


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## Canalsman (May 11, 2012)

yandoo said:


> Yay refund!
> 
> I just spoken to Maplins and Caracamp about their 12v laptop chargers and they both say it has to have the engine running on too?? WTF?



Absolute rubbish!

They may recommend that to ensure that you don't flatten your starter battery.

But you're going to use it on a leisure battery so it doesn't matter.

I have used one of these for months 80W DC 12V Car Power Supply Adapter Charger for Laptop | eBay with no problems


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## Bigpeetee (May 11, 2012)

I got mine from HP COMPAQ, DELL items in AC ADAPTER CHARGER store on eBay!

Works!!!!  Can't say more than that, even on a totally flat battery, it'll charge it up.

They're not always as quick as the one that came with the PC, but I've never had an issue.

I've fixed a 4 way outlet from my leisure batts so I can charge Laptopsx2 plus IPhone and sometimes an electric 12v blanket. (It's mainly psychological , but it does get slightly warm!! Daughter is such a COLD bugger!!)


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## cornishlad (Jul 26, 2012)

Just a thought...and I know this thread is a couple of months old..I just returned from a touring holiday and I always used my laptop on it's internal batteries when  parked up..In fact it's more convenient - less trailing wires ...Then I charged it up while I moved on. 

I suspect the charger/power supply is only required to output the full rated current when it's actually powering the laptop. When it's charging the laptop battery it doesn't need to supply so much..So an "underated" one might suffice and if it only works while the engine is running use can still be made of it. In touring mode this should work out ok.

When the engine is running, especially soon after starting, the 12v supply can be over 14v. After switching  the engine off the voltage can stay at 13.5ish for a while..but it will settle to about 12.6v. testing in these three situations may throw a little more light on the problem.


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## drkdeath5000 (Aug 12, 2012)

Hi all,

I'm new here but im hoping to get some advice please.

Next week im off to my caravan (first time) and could do with bringing the laptop so i dont fall behind with work. My only concern is this 12v malarky, other than it being 120v i dont have a clue really.

My laptop charger states input: 100 - 240v~2.5A 50-60Hz and output: 19.5v 7.7A so presumably the charger can operate at 100 - 240v and should run off a leisure battery which is 120v ? The laptop in question is a DELL XPS L702X.

Reading through this thread i see some have had to buy special adapters and inverters but considering the above do i need any of this. Should it not just be a case of plugging in ?

I have to travel 300 miles to try it so im really hoping i can get it working first time.

Thanks

EDIT: Here is my laptop charger http://www.ebay.co.uk/itm/GENUINE-D...Accessories_PowerSupplies&hash=item5199ba57ce


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## oldish hippy (Aug 12, 2012)

would not not like to put mockers on it think you find that a lesuire battery only 12 volt {well 13.8} unless you have ten of them


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## Bigpeetee (Aug 12, 2012)

Look at my previous posts up the page, I got a 12v charger from Ebay for my Compaq

Your charger is for AC only as in the wall outlets in the house, 240v in Europe, 110v in US & Canada etc so your charger can be used in any country in the world.

You need a 12v DC charger that outputs 19.5v DC and plugs into cigarette lighter.


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## Smaug (Aug 12, 2012)

The big problem with all these chargers is that the laptops are needing 19.5V dc, that is a problem with a 12v (nominal) input & the conversion process is inefficient. I have had 2 laptops regularly used on a boat, car & M/H - but both were designed to wor off a 12vDC input. Simply check the power supply, if it outputs at 12v, you can easily use it direct off a ciggy socket, if not, you need a DC-DC conversion & these are where your problems arise, they often need a higher voltage than even a fully charged battery can consistently supply.


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## drkdeath5000 (Aug 12, 2012)

Thanks for clearing up the confusion. I have no idea where i got 120v for the leisure battery from  but your right it is indeed 12v with 110AH.

The cigarette lighter charger would be ideal if i had somewhere to plug into but unfortunately i dont ... maybe there is something similar i can plug into an outlet in the caravan ?

As a last resort i will have my diesel generator to charge off but its noisy and expensive to run so id have to be desperate. Ideally im hoping to charge the leisure battery up using the generator through the day and then use the battery to run the laptop, lights and so forth. Laptop should last a good 8 hours with a full charge so once i get over the charging hurdle i should be good to go.


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## drkdeath5000 (Aug 12, 2012)

Smaug said:


> The big problem with all these chargers is that the laptops are needing 19.5V dc, that is a problem with a 12v (nominal) input & the conversion process is inefficient. I have had 2 laptops regularly used on a boat, car & M/H - but both were designed to wor off a 12vDC input. Simply check the power supply, if it outputs at 12v, you can easily use it direct off a ciggy socket, if not, you need a DC-DC conversion & these are where your problems arise, they often need a higher voltage than even a fully charged battery can consistently supply.



Hmmm, interesting ... my charger outputs at 19.5v so i guess i would have problems there. Might be using the generator after all then.


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## Bigpeetee (Aug 12, 2012)

Look on Ebay, you can get free standing ciggy sockets with a couple of croc clips for a few quid, I bought a 4 way one and have it wired across my leisure battery in the MH.

I use this to charge Ipods, various phones and a couple of laptops. The laptops use a charger that has 12v DC in and give 19.5 DC out, again bought off Ebay. Other members have bought a universal one from Maplins, my only concern with the universal ones is that the voltage selector can be knocked and as the PC connector is one of several sizes, these can become poor connection after a while.

If I'm stationary, even at night without the benefits of solar, my laptop charges up within an hour or so.

It's best to recharge before the alarms come on, say when at 25%.

I've been doing this for over 10 years now without a problem.

Much quieter than a diesel!! And cheaper in the long run.


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## maingate (Aug 12, 2012)

The Maplin charger also has a 5 volt USB charging socket built in.


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## drkdeath5000 (Aug 12, 2012)

Brilliant, id never even considered crocodile clips.

So presumably something like this would work...

Attach these to the battery with the cigar socket on the end - ADAPT IT 4 12V CIGAR SOCKET TO 2 CROC CLIPS CARAVAN CAMPING ACCESSORIES | eBay

Stick one of these in to give me a couple sockets and a usb, initially i'll only need the one though - CAR CIGARETTE LIGHTER CHARGER,2 WAY,3 WAY,4 WAY USB HTC,SAMSUNG,IPHONE SPLITTER | eBay

And for charging the laptop either one of these -
80W DC 12V Car Power Supply Adapter Charger for Laptop | eBay
Multi-Voltage Universal Laptop Power Supply : Laptop Power Supplies : Maplin Electronics
High Power Multi-Voltage Universal Laptop Power Supply : Maplin Electronics

Sounds simple enough now i've got it all down. My only two concerns would be

a) would these chargers even work with my dell ? A few years ago i had an inspiron which wouldnt charge up with anything but a dell branded charger.
b) how safe is this setup. is it likely to blow up or set the caravan on fire at all .


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## Bigpeetee (Aug 12, 2012)

Contact these people 19V PA-10 PA-13, NSPIRON 1501 6000 6400 9400 9300 e1505 items in DELL AC ADAPTER store on eBay! Tell them your model and they'll tell you which one

In over 10 years I've never had a problem.  Just don't allow your leisure battery to go flat, it'll knacker it.


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## rockape (Aug 12, 2012)

I always use an inverter,direct from the 110 amp leisure battery  and never have any problems :idea-007:


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## Bigpeetee (Aug 12, 2012)

rockape said:


> I always use an inverter,direct from the 110 amp leisure battery  and never have any problems :idea-007:



Works, but is very inefficient, you have the losses of two systems, plus some power supplies don't like the square waves of a modified sine wave that cheap inverters give.


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## rockape (Aug 13, 2012)

Bigpeetee said:


> Works, but is very inefficient, you have the losses of two systems, plus some power supplies don't like the square waves of a modified sine wave that cheap inverters give.


 Point taken,,, but it has never failed me


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