laptops - powering them

[Matthew Dowson]

My brother Mark who is based on the Welford Arm GU on ALPHA is pretty technically useless and asked me "I need to get a new laptop for home use, do you know of a good low-power use one that I can run primarily to watch DVD's when on the boat?", any laptop recommends and cheap power solutions?

 

He has no inverter and wants the cheapest solution possible, I told him to watch short films. I also said about time to get a small inverter. I did a search and came across something called a 12V converter, has anyone used one?

 

I happily use my laptop with a 600W sterling quasi sine and don't thinks its done my Macbook any harm, although I did have a dead battery recently (c2.5 yrs old). Comments gratefully received. I keep telling him to get onto the forum but at 58 he's a bit of a happy Luddite.

 

Great day for boating today isn't it?

 

Matt

[blodger]

My brother Mark who is based on the Welford Arm GU on ALPHA is pretty technically useless and asked me "I need to get a new laptop for home use, do you know of a good low-power use one that I can run primarily to watch DVD's when on the boat?", any laptop recommends and cheap power solutions?

 

He has no inverter and wants the cheapest solution possible, I told him to watch short films. I also said about time to get a small inverter. I did a search and came across something called a 12V converter, has anyone used one?

 

I happily use my laptop with a 600W sterling quasi sine and don't thinks its done my Macbook any harm, although I did have a dead battery recently (c2.5 yrs old). Comments gratefully received. I keep telling him to get onto the forum but at 58 he's a bit of a happy Luddite.

 

Great day for boating today isn't it?

 

Matt

There has been a fair bit of discussion on here about the efficiency of powering laptops via inverters and, some problems in using non-original power supplies (esp with Dell).

 

Maplins 12v stabilised supplies come out quite highly praised.

 

I have Amperors version (about 15.00 off Ebay) but have not used it to be able to comment on satisfaction from it.

 

There are lots out there using laptops on boats; I am sure they'll be along in a bit.

[colin stone]

My brother Mark who is based on the Welford Arm GU on ALPHA is pretty technically useless and asked me "I need to get a new laptop for home use, do you know of a good low-power use one that I can run primarily to watch DVD's when on the boat?", any laptop recommends and cheap power solutions?

 

He has no inverter and wants the cheapest solution possible, I told him to watch short films. I also said about time to get a small inverter. I did a search and came across something called a 12V converter, has anyone used one?

 

I happily use my laptop with a 600W sterling quasi sine and don't thinks its done my Macbook any harm, although I did have a dead battery recently (c2.5 yrs old). Comments gratefully received. I keep telling him to get onto the forum but at 58 he's a bit of a happy Luddite.

 

Great day for boating today isn't it?

 

Matt

 

Use a car 12v or lorry 24v laptop power supply. Will take 12v and produce a number of options eg 12v adaptor.

[Matthew Dowson]

Refined my search and indeed found a lot of previously posted info.

 

see here

[deletedaccount]

There's a new breed of low voltage intel processors out there. Much faster than previous netbook style processors.

 

Look for anything with an SU4100 processor and expect 5-8 hours battery life.

[blackrose]

There's a new breed of low voltage intel processors out there. Much faster than previous netbook style processors.

 

Look for anything with an SU4100 processor and expect 5-8 hours battery life.

 

My Sterling 1800w MSW powers my laptop ok, but in terms of reducing power consumption should I be using it off the inverter with a fully charged battery, or should I only switch on the inverter and charge up the laptop battery once it runs low and switch the inverter off again one the laptop battery is full, and so on?

 

Or does it make no difference?

[Matthew Dowson]

There's a new breed of low voltage intel processors out there. Much faster than previous netbook style processors.

 

Look for anything with an SU4100 processor and expect 5-8 hours battery life.

Worth knowing, thanks

[WotEver]

My Sterling 1800w MSW powers my laptop ok, but in terms of reducing power consumption should I be using it off the inverter with a fully charged battery, or should I only switch on the inverter and charge up the laptop battery once it runs low and switch the inverter off again one the laptop battery is full, and so on?

 

Or does it make no difference?

I can't think why it should make any difference - you have to replace the same amount of power as used by the Lappy whichever method you use.

 

Tony

[nb Innisfree]

My Sterling 1800w MSW powers my laptop ok, but in terms of reducing power consumption should I be using it off the inverter with a fully charged battery, or should I only switch on the inverter and charge up the laptop battery once it runs low and switch the inverter off again one the laptop battery is full, and so on?

 

Or does it make no difference?

 

We leave our laptop plugged in to Victron 16 hours a day and when it goes on standby the battery monitor shows it's using zero consumption.

[blodger]

I have just come across a cheap 70watt but claims to suit most laptops 12v dc supply off ciggy with loads of adaptors for about 3.50 all in obviously from just down the road, China.

 

Ebay Item number: 390103502126

[smileypete]

Refined my search and indeed found a lot of previously posted info.

 

see here

Also this thread (clicky)

 

Wonder what laptop sueb bought in the end.

 

cheers,

Pete.

[sueb]

Also this thread (clicky)

 

Wonder what laptop sueb bought in the end.

 

cheers,

Pete.

I ended up with another Toshiba because the fitting on my new 12v gizmo fitted. They definitely don't fit Dells

Sue

[Mac of Cygnet]

I have just come across a cheap 70watt but claims to suit most laptops 12v dc supply off ciggy with loads of adaptors for about 3.50 all in obviously from just down the road, China.

 

Ebay Item number: 390103502126

 

Yes I bought something similar from Maplins (not that cheap though). Despite having 12 adaptors none of them fitted my netbook (Asus Eee - they seem to have a much smaller size DC input than anything else). To be fair, Maplins took it back without question - even provided a bag. Took me ages to find a 12v charger at a reasonable price. When will these things be standardised - and the operating voltage? 19V! I ask you!

 

To answer the original question, I have only two leisure batteries, but the netbook happily charges up from almost zero in about half an hour with no noticeable adverse effects when the engine is not running.

 

Mac

[alan_fincher]

I have just come across a cheap 70watt but claims to suit most laptops 12v dc supply off ciggy with loads of adaptors for about 3.50 all in obviously from just down the road, China.

 

Ebay Item number: 390103502126

This does seem stunningly cheap, but looks remarkably like the lower powered offerings on sale over here, and even the smaller Maplin ones.

 

Typical UK price in the £20 mark at laest, so I'd be a bit suspicious here.

 

Note however 70 watts is not enough for many laptops. We have three in regular use, and IIRC none is actually rated less than 90 watts, so better to look for a supply of at least that if you want to be future proofed, (but if you have a smaller machine with lower demands of course 70 watts should be fine).

[Keeping Up]

The laptop destroyed my 225 watt inverter this summer, because it takes its power in short large pulses.

[alan_fincher]

Yes I bought something similar from Maplins (not that cheap though). Despite having 12 adaptors none of them fitted my netbook (Asus Eee - they seem to have a much smaller size DC input than anything else). To be fair, Maplins took it back without question - even provided a bag. Took me ages to find a 12v charger at a reasonable price. When will these things be standardised - and the operating voltage? 19V! I ask you!

 

We have found that with normal laptops, and a Maplin DC to DC converter, that 19 volts and the same co-axial plug is now fairly standard. (I'm talking fairly high specced laptops with screens around 17", not smaller notebooks, and the like.

 

On the other hand my Dell is a PITA, as it has a different plug, subtly different voltage, but is any way "got at" by Dell, such that it can recognise it's not connected to an official Dell supply, and hence refuse to charge, (although it can run off the Maplin supply - just not charge). I'm otherwise very happy with the Dell, but think twice about ifone is sensible if you want to run off 12 volts with no inverter.

[blodger]

This does seem stunningly cheap, but looks remarkably like the lower powered offerings on sale over here, and even the smaller Maplin ones.

 

Typical UK price in the £20 mark at laest, so I'd be a bit suspicious here.

 

Note however 70 watts is not enough for many laptops. We have three in regular use, and IIRC none is actually rated less than 90 watts, so better to look for a supply of at least that if you want to be future proofed, (but if you have a smaller machine with lower demands of course 70 watts should be fine).

Because it is cheap I'll have one just in case it works and for all the bits that come with it plus if a Laptop overpowers it it is still a small dc step up converter and you cannot buy them for this price!

 

I suppose you can use two and parallel the outputs if beefier is needed?

Edited September 12, 2010 by blodger

[Hippoclides]

My Sterling 1800w MSW powers my laptop ok, but in terms of reducing power consumption should I be using it off the inverter with a fully charged battery, or should I only switch on the inverter and charge up the laptop battery once it runs low and switch the inverter off again one the laptop battery is full, and so on?

 

Or does it make no difference?

 

If the battery is in, avoid running a laptop off the mains/inverter as much as possible. Only turn on the juice to charge the battery and then run it down to about 10% before fully charging it again. This will extend the life of your battery.

 

Further tips and explanation here.

[Gibbo]

Further tips and explanation here.

 

Sorry but that is utter bollocks.

 

He's the sort of person that concludes a cricket's ears are on its legs because it clearly doesn't hear the command to jump after cutting its legs off.

[jelunga]

Sorry but that is utter bollocks.

 

He's the sort of person that concludes a cricket's ears are on its legs because it clearly doesn't hear the command to jump after cutting its legs off.

 

Mmm, I agree with Gibbo.

 

After an initial few charge / discharge cycles, most secondary batteries are happiest and live longest when on float charge all the time, especially when in use. This pre-supposes that the float charge is correct voltage for the voltage and type of battery in use.

However, Nickel Cadmium cells differ. They do like to be discharged to their limit before re charging. This is because of some kind of "memory effect". God knows the science of it, but if you constantly discharge a NiCd cell to say 50% capacity then recharge it, it starts to think that the 50% capacity is really 0% charge and therefore loses capacity.

Well, that's what I read in the Sun.

 

Well actually, that is what the Army taught me 20 yrs ago. Has it changed?

 

Keith

[Gibbo]

Mmm, I agree with Gibbo.

 

After an initial few charge / discharge cycles, most secondary batteries are happiest and live longest when on float charge all the time, especially when in use. This pre-supposes that the float charge is correct voltage for the voltage and type of battery in use.

However, Nickel Cadmium cells differ. They do like to be discharged to their limit before re charging. This is because of some kind of "memory effect". God knows the science of it, but if you constantly discharge a NiCd cell to say 50% capacity then recharge it, it starts to think that the 50% capacity is really 0% charge and therefore loses capacity.

Well, that's what I read in the Sun.

 

Well actually, that is what the Army taught me 20 yrs ago. Has it changed?

 

Keith

 

No, it still applies. But as you say, only to NICad dry cells.

 

It's something to do with tiny whiskers growing inside the cell that only get removed following a charge from truly empty to full. Or something, I can't really remember. But whiskers are in there somewhere.

[nb Innisfree]

Mmm, I agree with Gibbo.

 

After an initial few charge / discharge cycles, most secondary batteries are happiest and live longest when on float charge all the time, especially when in use. This pre-supposes that the float charge is correct voltage for the voltage and type of battery in use.

However, Nickel Cadmium cells differ. They do like to be discharged to their limit before re charging. This is because of some kind of "memory effect". God knows the science of it, but if you constantly discharge a NiCd cell to say 50% capacity then recharge it, it starts to think that the 50% capacity is really 0% charge and therefore loses capacity.

Well, that's what I read in the Sun.

 

Well actually, that is what the Army taught me 20 yrs ago. Has it changed?

 

Keith

 

I think the advice is based on nickel cadmium batts which are rarely found in computers and phones etc.these days.

 

Edited to add: Just spotted Gibbo's post!

Edited September 12, 2010 by nb Innisfree

[Hippoclides]

Sorry but that is utter bollocks.

 

He's the sort of person that concludes a cricket's ears are on its legs because it clearly doesn't hear the command to jump after cutting its legs off.

 

I freely admit to knowing nothing about battery chemistry. So you may well be right that the explanation of the charge-discharge stuff resembles testicles in some way. However, I have observed that running laptops on mains all day kills their batteries faster. And most manufacturers don't advise it, so perhaps there is a reason for this.

 

Li-ion batteries appear not to like heat. Most modern laptops produce a lot of heat. On mains, because their power management systems generally clock them faster (not always user-configurable either), they will generally run hotter still. So running on mains constantly, with the battery in, is unlikely to do it any good. I wouldn't go as far as sticking it in the fridge but if you're running on mains/inverter and the battery is charged, why leave it in?

[Gibbo]

I freely admit to knowing nothing about battery chemistry. So you may well be right that the explanation of the charge-discharge stuff resembles testicles in some way. However, I have observed that running laptops on mains all day kills their batteries faster. And most manufacturers don't advise it, so perhaps there is a reason for this.

 

Li-ion batteries appear not to like heat. Most modern laptops produce a lot of heat. On mains, because their power management systems generally clock them faster (not always user-configurable either), they will generally run hotter still. So running on mains constantly, with the battery in, is unlikely to do it any good. I wouldn't go as far as sticking it in the fridge but if you're running on mains/inverter and the battery is charged, why leave it in?

 

Yes, once the battery is fully charged you're better off removing it. Heat does indeed ruin lithium batteries. Some people seem to be saying run the laptop from the batteries.

 

The website linked to compares laptop batteries with mobile phone batteries and mentions the huge difference in lifespan, then goes on to conclude that it's because the phone battery is being permanently used. This is the bit that's bollox.

 

The reason phone batteries last so much longer than laptop batteries is because the discharge current is (relative to the size of the battery about 1/50 that of a laptop.

 

Get a brand new phone and a brand new laptop. Switch them both on and see how long they last. The phone will go on for days and days. The laptop will be flat within a matter of hours. That's because laptops absolutely batter batteries and phones don't. If you talked on your phone permanently it would then get treated a bit like the battery in a laptop and would suffer the same very short lifespan.

[smileypete]

I freely admit to knowing nothing about battery chemistry. So you may well be right that the explanation of the charge-discharge stuff resembles testicles in some way. However, I have observed that running laptops on mains all day kills their batteries faster. And most manufacturers don't advise it, so perhaps there is a reason for this.

 

Li-ion batteries appear not to like heat. Most modern laptops produce a lot of heat. On mains, because their power management systems generally clock them faster (not always user-configurable either), they will generally run hotter still. So running on mains constantly, with the battery in, is unlikely to do it any good. I wouldn't go as far as sticking it in the fridge but if you're running on mains/inverter and the battery is charged, why leave it in?

Very good article on prolonging Li-ion battery life here: (http://www.batteryuniversity.com/parttwo-34.htm)

 

cheers,

Pete.

Edited September 12, 2010 by smileypete