Running a laptop

Pollik

Guest
There have been many threads on MH electrics...here is another one!

I have an 11yr old Bessecar - single leisure battery.

I am a heavy laptop user and I am beginning to find sites with electric hook up rather attractive.

At the moment, I charge while I drive and get about 2hrs battery usage from than (only 1hr if I am using the internet). I recharge from the cigar lighter, though a 300W inverter. At idle, the engine produces enough to power the laptop in heavy use (graphics) and to (very) slowly charge the laptop battery. The AC charging unit is rated at 65W. The cigar lighter functions without the ignition, but as I suspect that it is still powered by the van battery, I will only use it to recharge my phone.

I have tried running the laptop off the leisure battery, through a 12V DC charger, but that has a tendency to blow fuses and anyway seems to badly affect the rest of the 12v system (flickering lights). I have tried using an 75W inverter off the cigar lighter - this works most of the time, but quite often fails to recharge the laptop at idle.

The solutions that I can see available to me are:-

- carry on using the laptop with the 300W inverter, leaving the engine idling. Expensive in diesel, smelly, noisy for other MHers and my layout is such that I would have to sit in the front forward facing seat to use it.

- solar panels. This won't overcome the problem I have with running the laptop off the 12v leisure system

- wind generator. Ditto.

- generator. Expensive initial outlay, noisy for other MHers, no obvious place to store the heavy generator, wary of cheap imitations, high maintenance costs, not really suitable for all weather use (eg heavy rain) without building some kind of shelter...which I then have to store somewhere I haven't got. On the plus side, I could have one that runs on LPG (I have Gaslow).

- get a hamster in a wheel

- get a life

I would like to find a solution that ideally is not too expensive or jury rigged.

I thought about a second leisure battery, but on the advice I have seen elsewhere here. I would need to buy two batteries (the present one is probably old), I don't think that the I would get the wattage I need and even if I could, I don't think the 12v wiring will be rated high enough.

Of all these, the best solution seems to be a generator, much as I hate the idea. One practical problem I have is that, although I can pick up theory fairly easily, my DIY skills are poor (drills and such like).

Does anyone have any thoughts, advice or recommendations, please? :cool:

Polly
 
You should buy a 12v laptop charger - they are less than £20 and run it from a cigarette lighter socket. The reason you are blowing fuses and causing the lights to dim is that you are allowing the battery to get flat. It draws a lot of current when flat but lessens significantly as it approaches full charge and once charged takes a minimal amount. So you should always run the laptop with the charger connected thus avoiding the big hit when discharged.
Best regards
Mike
 
I have tried running the laptop off the leisure battery, through a 12V DC charger, but that has a tendency to blow fuses and anyway seems to badly affect the rest of the 12v system (flickering lights).

I wonder if your leisure battery has reached the end of its life or is not being charged properly when you are driving. Or if the wiring to the cigarette outlet you are using is inadequate.

When you arrive at your destination, the leisure battery should be as fully charged as your main battery and should have no trouble recharging the laptop battery.

A 65W 12V charger will take about 6 amps, so the fuse needs to be at least 10 amps (and the wiring needs to be heavy enough too!). You may want to add a cigarette socket on heavy leads with a fuse connected directly to the leisure battery or its main connection point depending on how the wiring is done.

The other consideration, and probably why you are blowing fuses (what amperage are they?) is that the charger can draw a much higher current in the first few seconds, which can blow the fuse or trip a breaker. A slow blow fuse would be a good idea.
 
I have one similar to this

120W Laptop Car Adaptor : InCar Power Adaptors : Maplin

It charges the laptop up quite quickly. I use the laptop off its battery until its flat and then sit in the front dinette and run the laptop off the engine battery for an hour or so until its charged again.

I recently bought an Acer Timeline laptop which has an 8 hour battery life. Perhaps you can purchase a 9 cell battery for yours similar to mine which will give you extended use off hookup.
 
Some good responses, here, thank you.

@Mike - I will try that idea - plugging in the laptop fully charged, although I don't think this is the issue. I am pretty certain that the laptop battery has, on some occasions at least, been fully charged and still having the problems. It will have to wait until tomorrow or the day after for me to recharge it.

@Geo - That's possible. The MH is 11 years old and I will guess that the battery has never been replaced. The fuse on this circuit (which runs the sparky things that light the gas and the 12v socket) was rated at 5 amp when it first blew. Whether that is the amperage is should be, I don't know, but I haven't felt inclined to put in a 10 amp to try it out! Putting in another fused circuit direct from the battery is an interesting idea - not sure that I am practical enough to do it, though. I am OK on theory, mostly, but it is best not to put tools in my hands. ;) I have no idea what a slow blow fuse is - currently it is fused with blade fuses.

@Barry - I am a bit loth to run the laptop off the engine battery - push starting it would be a bit tricky on my own! Mine is an Acer Aspire which was bought without this kind of travelling in mind.

Thanks again for your help!

Polly
 
Hello Polly

I've just clocked this thread and it sounds horribly complicated.

Up until a year ago we had a lot of problems running a power hungry Toshiba laptop, but since buying a netbook it's been a doddle. No internal dvd drive of course but an external hard drive or just a big sd card will do nicely for films etc.

It's worked for us, and we even watched a couple of programmes of dvd on the 10" screen with no problems. Also, if you do go down the netbook route get a hold of a X-Mini speaker.It charges from usb and put out some incredible sound. I'll try to put a picture in this reply to show our 'home cinema' in action.
 
I bought a new charger for my Compaq from smart_parts_uk on Ebay, cost £18.90 inc P&P

Runs from 12v, but there isn't an instantaneous surge of current that blows the fuise from the lighter socket.

I did however buy an additional socket with crocodile clips to connect across my leisure battery direct, therefore not putting any load on the existing cables.

It's meant that I can now sit at the table, plug in to the leisure battery and use the laptop to my hearts content. It uses upto 65w of power and as it has a 17.9 inch screen, uses a bit more than others.

If you're worried about the leisure battery, purchase a cheap digital meter, from £5 in cheap shops or markets and connect across your leisure batt to watch what is happening to it when you use the PC.
 
Runs from 12v, but there isn't an instantaneous surge of current that blows the fuise from the lighter socket.

Assuming you mean IS...

If you haven't already, try plugging it into the 12V without the notebook connected. Then plug it into the notebook.

But I know what you mean, My adapter does that on 220V, too and blows the cheap EHU circuit breakers when I only pay for a few amps.

Usually the second time I plug it in, it is OK. The capacitors have charged.

Poor design, IMHO.

Peter
 
stop playing around .my laptop battery is completely knacked .it runs on 240 all the time. so when in travel mode you need 6x80watt solar and 700amp of battery and a 2kw inverter .works for me .alsohandles 240 house fridge and lots of other things .
 
actually i have another one to go on . be 800amp soon .(not including the trucks batteries they link to make 24volt.) come on though i use 240volt washing machine . and lots of other things. at moment its parked next to house powering a fridge deepfreeze computer telly .plug in hoover when nec. got to make it pay for itself.
two of the batteries will be in line on a 24 volt to 12 volt charging system when trailer is unhooked always have good jump start facility for others .when hooked up a suzy lead connects them to the others for charging on the move. i also run another inverter in the cab for drills grinders when at home but not at home. solar as never been so cheap. 80wat panels on ebay for 154 quid all the time. get them fit them forget them. i would like to have 20-30 hooked into the grid can make a few bob. its getting an electrician with the right bits of paper to fit the outlet meter with out supplying rip off panels .might have one soon . reckon 3 yrs will be in profit,but not if you pay their prices for panels. cheers alan.
 
Alan, Have you got any photos of your rig? Would love to see them

Barry
 
hi,bary if you let me have your email addy i might be able to send you some then you can put them on here. i have done that on other sites. cheers alan.
 
a friend just turned up .some of mitzy and some of vwlt. one is xmas dinner in maroc.
 

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Polly,(yes back to her ;) )

Firstly your inverter is a big un ,Why ? as that sucks up the little power you have available.
Secondly,your ' leasure battery ' i would think needs to be binned,and splash out on the biggest amp possible,this will change your use drastically.
Why not a solar panel ? not sure why you are against one,since fitting mine (100w) 2 years ago,i can run without 240v anywhere,without worries,using my pump,shower,lighs etc..
If you can afford,buy 2 leasure batteries in tandum,otherwise like said the biggest amp one.
 
a friend just turned up .some of mitzy and some of vwlt. one is xmas dinner in maroc.

Its cerainly an interesting Rig Alan. IF we ever meet up we will have no trouble spotting you!

Nice one
Barry
 
The 12volt power supplies for running a laptop are in fact a mini inverter from 12v to approx 19v depending on your laptop.

By using an inverter to 240v means you are using losing power at they aren't 100% efficient, feel the heat, that warmth is using your power, then when using the charger fro 240v to 19v ish that to has a loss so gets warm using even more power, so just one specific power supply is more efficient.

To save power Use solid state memory, USB stick, SD card etc as these dont use motors to hunt for data.

I sometimes use an EEEPC that runs Linux and only has solid state memory, uses little power, but the screen is a bit on the small side!!,
 
I think you should look at this a different way entirly.

1-1.5 hour battery life is simply pitiful ! I think you should upgrade your laptop and buy a modern hi-efficiency netbook . If all you are doing is sufing on the move then a netbook is perfect for your needs and you'll get an entire day from a single charge. We get 10 hours battery life from a single charge !

I bought 2x Hp Mini 110- 3108 netbooks for the missus and myself for use in the campervan. We've ended up using them at home in preference to the 2x huge HP G6000 laptops we have at home.

We stream live tv and recorded tv from BBC Iplayer and using a VGA lead watch it through our 19" tv in the campervan.

I download all my photo jpegs and video when i get back to the CV after a days walking and exploring and it will manage all my image editing.

We have loaded all our music CD's and plug the netbook into the CV's CD/radio system to play our music collection and intend to download our video/movie collection also.


With a 260Gb hard drive and 2Gb memory it will cope with anything you can throw at it.

If you shop around you can buy them for as little as £175.00
 
Money is always an issue. I am not against solar panels as such, it is more that I don't want to spend more than I need on a van that I am thinking of changing within the next year.

I have now replace the old leisure battery with 2 new 75's...yes I know I should have gone bigger, but these were less than half the price of the 100+'s. My own laptop, following advice is now working fine - the solution seeming to be to hook up to 12v system while the laptop is fully charged. Problem solved. It is running off a cigar lighter charger which has settings for different voltages. It came with about a dozen tips, one of which fits my laptop, but none of which fit my partner's laptop.

That second laptop - I have tried using a smaller inverter 75W to convert 12V DC to 240V AC and then using the mains charger to step it back down...not a very efficient set up. :/ Even with mine disconnected and starting that laptop from a full charge, either the van electrics flick in and out, or the laptop does. It is very frustrating.

I looked at netbooks, but I don't think they will meet my needs. I am heavy PC user - internet, music, graphics, games and I benefit from a 16" screen (at home, I plug in a monitor to double the size of the usable area). But, reading peanut's comments, a netbook might work for my partner...and solve the power issue we have. Changing the appliance rather than the power supply would probably be cheaper...useful thought, thank you..

And again, thank you everyone who is contributing!!


Polly
 

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