Best laptop for rv life

[zero]

So just to keep up with 4 hours of computer use you would need to replace 100 watts. This won’t happen with a 100 watt rated panel in 4 hours of direct sun light double that you may come close..

Here in central NY, a 120 watt panel will put out 6 amps @ 14 volts on rare occasions. 3-4 amps is more common. I have 5400 watts of solar panels in a fixed mount. They make 4000 KWH per year. That's 11 KWH per day total - and 244 watt hours per each 120 watt panel per day. I.e. a 120 watt panel for a year-long-average makes 10 watts per hour (including nighttime). Factor in what it does only when daylight- 24 watts per hour, on average. With a charge current of 14 volts, that's about 1.7 amps on average. I live in area with not-so-great sun in the summer and very little during some of the winter months. Someone with my panels in the southwest could get twice the output.

[Maineah]

Here in central NY, a 120 watt panel will put out 6 amps @ 14 volts on rare occasions. 3-4 amps is more common. I have 5400 watts of solar panels in a fixed mount. They make 4000 KWH per year. That's 11 KWH per day total - and 244 watt hours per each 120 watt panel per day. I.e. a 120 watt panel for a year-long-average makes 10 watts per hour (including nighttime). Factor in what it does only when daylight- 24 watts per hour, on average. With a charge current of 14 volts, that's about 1.7 amps on average. I live in area with not-so-great sun in the summer and very little during some of the winter months. Someone with my panels in the southwest could get twice the output.

Exactly. The system we have built at my neighbors house is about the same size and to make up for the lack of sun during the winter months here in Maine we have installed an 1800 watt wind turbine to take up the slack, wind we have sun light we don't. A solar system for camping relies on two factors one of them being frugal use of power and enough panels to deal with the usage under low power generation situations.

[zero]

Exactly. The system we have built at my neighbors house is about the same size and to make up for the lack of sun during the winter months here in Maine we have installed an 1800 watt wind turbine to take up the slack, wind we have sun light we don't. A solar system for camping relies on two factors one of them being frugal use of power and enough panels to deal with the usage under low power generation situations.

Anybody with solar in the northeast has to be prepared for days, and sometimes weeks with no sun. Also no wind at times and sometimes no wind or no sun. That being said, we get the most wind (late winter and spring) when the days are often the darkest and gloomiest. One big draw-back to a non grid-tie system. In the summer I get days when my panels make 3 times what we use. If I was not hooked to the grid - it would all go to waste. NO way of "saving it for later." In the end, I lose what I don't use anyway - but to a lesser extent. The power company gives me "credits" for all the extra power I've accumulated. After 2 years - they confiscate it. They set my credit-balance to zero and sell the power to someone else - and pocket the proceeds. I guess the trick is . . . when the time comes near to zero the credit - call all your friends and have an "electric use" party and use the excess for something. Not sure what.

I've got a real good full time stream and I've considered installing a water-powered turbine. But even though I own the creek - I am not allowed to do anything in it without endless amounts of permits from the conservation department.

[zero]

There are a lot of DC to DC converters on the market for use with laptops. Some of them are for one specific series and brand name of laptops. Other aftermarket DC to DC converters have multiple choices for voltage output plus a collection of interchangeable tips to fit various brands of laptops. Some laptop makers offer a DC to DC converter in their internet stores. Chances are you can find one of these DC to DC power supplies to fit your particular laptop.

Yes, I've posted links to a few brands of them. Stamar says they are "junk" and he claims no better then using an AC power supply plugged into an inverter. I don't agree at all but we can all think what we like, I guess. What we think though does not change reality.

Most of the DC to DC step-up converters (12 volt to 18 volts DC) have a 90% efficiency rating which is about has high as I think anyone is going to find. Sure beats the 40-50% efficiency of an AC supply plugged into an inverter.

[Totem]

Anybody with solar in the northeast has to be prepared for days, and sometimes weeks with no sun. Also no wind at times and sometimes no wind or no sun. That being said, we get the most wind (late winter and spring) when the days are often the darkest and gloomiest. One big draw-back to a non grid-tie system. In the summer I get days when my panels make 3 times what we use. If I was not hooked to the grid - it would all go to waste. NO way of "saving it for later." In the end, I lose what I don't use anyway - but to a lesser extent. The power company gives me "credits" for all the extra power I've accumulated. After 2 years - they confiscate it. They set my credit-balance to zero and sell the power to someone else - and pocket the proceeds. I guess the trick is . . . when the time comes near to zero the credit - call all your friends and have an "electric use" party and use the excess for something. Not sure what.

I've got a real good full time stream and I've considered installing a water-powered turbine. But even though I own the creek - I am not allowed to do anything in it without endless amounts of permits from the conservation department.

you just need to make a water battery. use excess electricity to pump water up hill or into a towered storage container. Running the water battery in reverse runs water through turbines (pipe turbines not stream ones) generating electricity until the tank is empty.

[Maineah]

Grid tie inverter?

[zero]

you just need to make a water battery. use excess electricity to pump water up hill or into a towered storage container. Running the water battery in reverse runs water through turbines (pipe turbines not stream ones) generating electricity until the tank is empty.

There is a big one of those not too far from me. The Gilboa Dam Project. They use electricity all night - when demand is low - to run electric water pumps to fill up a huge lake. When morning comes they pull the plug and let the water run turbines.

In Holland during the windy season - they use the excess electricity to run air compressor and fill up huge tanks of air. When the doldrums come (no wind) they slowly let the air out to run electric generators.

That sort of thing isn't easy nor cost-effective on a small scale.

[zero]

Grid tie inverter?

Yes - I've got two big Outback grid-tie inverters here. Without grid-tie, having solar here would not be worth the bother.

[stamar]

if you have the equipment handy to show electrical draw why show us electrical draw from a laptop plugged in?

i know my inverter made by gopower in canada claims to be 98% effecient. I think they claim to be the worlds most effecient somewhere. Sometime, with some inverter they make.

the 98% claim is the same thing, its the dc to ac conversion. its very efficient, in fact theres nothing out there thats not 90% effecient at this point.

Thats the number they choose to advertise, because they know the true effeciency is complex

but whats way less effecient is the ac to dc conversion going on. The devices you are showing are no more effecient in converting ac to dc than the boxes that come with the laptop you tested.

if you have the equipment to test a draw and really want to contribute something to this question

buy one of your dc to ac to dc converters. either the one you like or one of the ones for 12$ ideally both though.

get your standard cigarette plug dc to ac inverter. use the laptops own ac to dc inverter

basic and simple. I have not done this test at all it might not have been done. But I offer you that a dc to ac to dc converter will be about as effectient as using a seperate dc to ac inverter box and plugging in the laptops own ac. because thats exactly what youre doing there. And depending on the device what they are selling as a car charger could be something made in china 10 years ago as opposed to what came with the laptop is at least made this year.

[stamar]

i definitely wrote down the data you had for the watts per panel

I didnt actually figure that out at all even though theres a conversion thing I saw that will show the average watts for the city you live in vs cloudy days.

I also dont have the watts used for the laptop but I can show you my laptop im probably getting

http://www.bestbuy.c...!g!!18463087999

I definitely decided not to actually get the lowest power laptop because I wasnt impressed.

lets assume it uses the same amount of power one of yours does at random. so between those two numbers, 250 watt panels in the northeast and the average laptop how many hours a day do the panels power the laptop? year average is fine.

So the difference is what i need to power with the alternator.

again i have to be clear though im not working on this project til january but if I had that data in my notes I could be done already.

[stamar]

theres definitely good data that you gave us that shows that some of the ac to dc boxes are effecient.

Even though theres no real incentive for them to be. even their low power models are only presented to consumers based on their own battery life. the actual ac to dc box can be a peice of crap because no one will ever know what it is doing.

they may even get paid more under the table to make them waste power.

Im going with the assumption that the ac to dc box of a samsung laptop is just as crappy as the one that im using with my asus. It might not be but Im assuming it is so Ill have a straight dc to dc inverter.

Its not for sale retail commonly actually im going to have my buddy make it.

however you can buy something like it from asia commonly heres an example

http://www.ebay.com/...=item257833739b

http://www.ebay.com/...=item27c400eee8

is closer to what im using

.im not buyiing any of these devices bbut sometime in january ill put some time and thought into something an rver can buy online. Someone else can definitely try these out i plan to use

something closest to this

http://www.amazon.co...8&condition=all

but it doesnt have the big heat synchs because its using much less power, but its for the golf cart

i dont recomend any of these devices im just trying to help someone whos looking for one with good points to start. Im not shopping for one at all unless the laptop overloads the one i have.

[stamar]

http://www.campertra...ower_supply.htm

this is quite possibly the circuit board i showed connected to a cigarette adapter and the laptop connectors.

I dont guarantee it though. but it could be a buy it all at once sort of thing.

it is a real dc to dc converter though.

[stamar]

this is definitely the right item

http://www.jtsonline...p-projecta.html

this is from a solar rv store.

however, its being sold at a rip off price. but thats what you are looking for, from the exactly correct source. Solar trailer laptop adapter. make sure to avoid all the things with the ac to dc power brick at the end, those are all crap.

the real item is actually smaller than a pack of cigarettes. but if its small it doesnt have the heat sinks that a larger laptop needs

now an adaptable one like these is not nearly as effecient as a non adaptable one, like the golf cart circuit, thats like 99 percent efficient. Thats what im shooting for.

[stamar]

http://www.meritline.com/80w-power-adapter-dc-12v-car-use-for-laptop---p-30057.aspx?source=fghdac&gclid=CNyZ8tzJo7QCFYN_QgodBGgA3A

this is potentially the same item the solar rv store is selling for 75$

[Maineah]

if you have the equipment handy to show electrical draw why show us electrical draw from a laptop plugged in?

i know my inverter made by gopower in canada claims to be 98% effecient. I think they claim to be the worlds most effecient somewhere. Sometime, with some inverter they make.

the 98% claim is the same thing, its the dc to ac conversion. its very efficient, in fact theres nothing out there thats not 90% effecient at this point.

Thats the number they choose to advertise, because they know the true effeciency is complex

but whats way less effecient is the ac to dc conversion going on. The devices you are showing are no more effecient in converting ac to dc than the boxes that come with the laptop you tested.

if you have the equipment to test a draw and really want to contribute something to this question

buy one of your dc to ac to dc converters. either the one you like or one of the ones for 12$ ideally both though.

get your standard cigarette plug dc to ac inverter. use the laptops own ac to dc inverter

basic and simple. I have not done this test at all it might not have been done. But I offer you that a dc to ac to dc converter will be about as effectient as using a seperate dc to ac inverter box and plugging in the laptops own ac. because thats exactly what youre doing there. And depending on the device what they are selling as a car charger could be something made in china 10 years ago as opposed to what came with the laptop is at least made this year.

Have a look at the pictures I posted one is the computer running on a DC to DC converter the other is a computer running on a DC to AC to DC set up. That set up drew all most half again as much power as the DC to DC unit. It is a lose, lose situation. The laptop plugged in drew pretty much the same amount of line power as the DC to DC unit. An other thing I found out was do not over buy an inverter if 100 watts will do it don't buy a 350 thinking it's better it's not their efficiency goes up when they are close to their rated power.

[stamar]

well im trying to take a note to see something to apply to it.

Nope cant really see anything in this round that helps too much.

I made an estimate of 250 watts in panels. when I put it to use im going to be in portland in the middle of winter. talk about the worst case scenario, I would say its sunny 2 days a week.

when I get some real life experiments Ill get a picture of what needs to be expanded.

its hard to tell how discharged a battery gets.

there is data here that shows i can estimate the amount of power coming from a 250 watt panel and its a good guestimate. using the random 1/4 output number i guess thats 60 watts. I think that does or doesnt include nighttime is half the time..... 30 watts

and strangely enough that is the draw of the random laptop. I didnt think I would have enough charging for it but maybe I did guestimate right. in which case solar is a great investment. for 300 bucks I have a system set up to run a laptop, and the alternative of running the gas would cost 300 ....literally a month.

Even the sure fire set up of a champion generator for 200..... and 100 i guess in gas it going to last a month or two in a miracle. my solar investment is starting to look perfect. In the event it needs anouther 125 watt panel im ready for that too.

[zero]

.

I dont guarantee it though. but it could be a buy it all at once sort of thing.

it is a real dc to dc converter though.

Where do you come up with these statements? I posted an ad for one (Power Stream) and you claim it is "junk" and "not a real DC to DC

converter. Then you see one that you like the picture of in the ad and say it IS real?

How about using some "real" facts? To the user - when it comes to getting the most run time - all that counts is the efficiency rating. The Powerstream I posted is tested at 90% efficiency. Have you seen specs for the one you say is "real" that are any higher? I doubt it.

Also since you claim the one you like is a "real" one - please explain this exclusive process they use to boost 12 volts DC up to 18 volts DC with no pulse-width modulation or high-speed switching (i.e. alternating current) in the process?

Even the high-end DC to DC boost converters that the US Military buy for $1000 each are only rated at 85% efficiency.

[stamar]

There's no test of 90 percent efficiency unless you do one. Its just the advertising claim.

Maineah aparently has the equipment maybe he can do one.

I make no claims to any of those links I'm not even looking into them but tryiing to be helpful to someone shopping online and how to recognize a peice of junk and the real thing.

I won't be looking up anything for you unpaid lol but I do spend a lot of my free time trying to help. I know I've said five times now I'm. Working on this after christmas. I won't have any sort of draw measurements ill use an actual dc to dc converter. Most have claimed effeciency of like 95 percent or so.

[Totem]

I will have my ammo box stove TEG generator and dc to dc converter completed by new year. I will report back on its efficiency. I think I got the dc to dc for like 35$ on ebay or amazon, cant remember. It was specifically recommended to me by the guys that make the TEG stove top generators. They claimed it was bulletproof and charged batteries well and even supported some light loads.

[stamar]

I will not be testing any sort of inverters or transformers as a dc to dc up step is called for their power usage

Car adapters etc.

The reason I won't is I already have, I've used all of the various car adapters bothh the dc to dc transformer with the switching voltage, and the dc to ac to dc car adapters, and the dc to ac inverters...

I've used them all. Many times over with lots of laptops. And ill tell you what the best thing to use, and it will be the same thing they would tell you on a saiiling forum, and a rv forum, and a solar forum. It would be the same thing I linked from the trailer solar forum.

As to how dc goes up in voltage its simple but who gives a flying. How does dc transform to ac? Who cares? In its right place a debate between amature electricians might be entertaining but this is the toyota rv forum. Were looking for the solution that works the best for rvers or more for toy homes which are mostly rvs without generators.

I know how those car adapters work compared to the dc adapters I showed because I used them both. The dc ac dc car adappter can be the most wasteful least effecient solution, and the dc to dc transformer whatever its effeciency really is, claimed at 95 percent is really the best. I don't know exactly why, and it would be nice not to know why.

But when I have it hooked up in jan ill do a test

[Maineah]

Every, again every electronic device has losses that's why they get warm. If you have an inverter at 95% efficiency and a power supply at 95% efficiency you'll have a net loss of 10% before it even gets to the computer. If you have a DC to DC converter at 95% you'll have a net loss of 5% it's simple math. I grabbed an inverter I had laying around nothing special standard run of the mill inverter sitting doing nothing not powering any thing just turned on it drew 8 watts from the battery so that inverter was all ready running at an 8 watt deficit before it even powered up any thing. Yes some maybe less but each and every one has idling current with out exception even a DC to DC but during the tests I did the DC to DC had 7.5 watts less current draw then the inverter with out the computer power supply even plugged in yet. Now you can disregard the facts that's up to you but if you are concerned about power consumption you may want to research this stuff your self. Other wise just get bigger batteries and more solar cells and hope the sun shines.

[stamar]

Ha I love and respect you alll but I'm beyond tired of this bs. Maineah ill get back to you on a power draw.

So far as I know I will be the first toyota rv with a dc to dc transformer for 12 to 19 volts for a laptop. Far from the first rver. But assuming no one sets one up between now and feb let's say.

If someone else has that kind of horsepower to do it before I have time to ill be stoked. I don't even have the laptop I'm powering yet.

Ill have two laptops, and two diifferent ways to power them and ill have a real life test if not an actual power draw. It should be helpful

No one has time to test all the devices for sale on the internet. Common sense just shows you similar devices willl be similar.

All maineahs data is the same as mine, avoid the ac to dc power bricks when on deep cycle power. Some are good some are bad and I don't have a way to test them other than. Real liife so I wrote them out of the equation

[stamar]

I did a real life test between a home made dc to dc transformer and the standard car adapter with the ac to dc brick and it lasted at least three times as long. More importantly it kept going much longer before it stopped.

[stamar]

ya maineah youre so totally lost youre not even sure who youre talking to.

I am using a real dc to dc transformer in my set up. Im almost sure everyone else on earth is using a dc to ac to dc inverter. so you are actually communicating your rant with the only person it doesnt apply to.

Id be interested in a real life test with your equipment on a real dc to dc transformer, since so far as I can tell its never been done.

if you have the equipment all you need is the transformer. you can try one that I linked from ebay for 4$

[Stevo]

Sorry for the dumb question but you obviously know a lot about this subject...

If I want to run my Macbook Pro 17 in my motorhome (with solar panels), what do these DC to DC Convertors do here http://www.powerstream.com/dc-dc.htm that I couldn't do with a DC adapter like this http://tinyurl.com/bdhvh28 or this http://tinyurl.com/a3gzkxx?

Thank you.

Most of the DC-to-DC converters sold for lap-tops are 90%-92% efficient. You call that crap? Tell me about the "better" ones you know of that greatly exceed that 90%-92% figure. I think you are dreaming. Cite some real figures from specific devices (I already have). In fact, when something is already 90%-92% efficient there is not an awful lot of room for improvement. Would you spend big dollars to maybe gain 1 or 2%? There is an added factor called "cost efficiency."

[stamar]

the first list shows actually every type of dc dc converter ive ever seen from household ones to dc ac dc ones to the bare board ebay ones. all expensive.

the second one is of unknown useage i wouldnt think its too effecient.

it would work, seems expensive for what it is.

[zero]

Sorry for the dumb question but you obviously know a lot about this subject...

If I want to run my Macbook Pro 17 in my motorhome (with solar panels), what do these DC to DC Convertors do here http://www.powerstream.com/dc-dc.htm that I couldn't do with a DC adapter like this http://tinyurl.com/bdhvh28 or this http://tinyurl.com/a3gzkxx?

Thank you.

The other boost-converters you mention look fine to me. I only mentioned the Powerstream as one example of many. They ALL have loss. There is no way to take 12 volts DC and boost it up to 18-19 volts DC without loss. There is also no way to do the boost with pure DC current throughout the process. There are no "magical" converters out there (like maybe Stamar is claiming?). All I've seen run around 90% efficiency that is far better then running a laptop with the AC-to-DC converter plugged into a DC to AC inverter. The biggest loss in that setup is the AC to DC converter that came with your laptop. Some are only 50% efficient. Used with an inverter you're talking about 60% loss to heat!

If your power-outlet or cigarette lighter has standard wiring - it will be rated 20 amps @ 12 volts. I.e. that's 240 watts. That power supply you showed a link for is rated for 85 watts.

[Maineah]

ya maineah youre so totally lost youre not even sure who youre talking to.

I am using a real dc to dc transformer in my set up. Im almost sure everyone else on earth is using a dc to ac to dc inverter. so you are actually communicating your rant with the only person it doesnt apply to.

Id be interested in a real life test with your equipment on a real dc to dc transformer, since so far as I can tell its never been done.

if you have the equipment all you need is the transformer. you can try one that I linked from ebay for 4$

. There is no such a thing as a DC to DC transformer transformers do not will not work on DC. What ever you are talking about is not a transformer it is a DC to DC converter yes they do exist and they work fine. No one has ever tested one because there is no such a thing as a DC transformer, transformers have to have alternating current in order to work. Inside of DC to DC converters are inductors (a form of transformer) but the electronics produce ac for the transformer to stepup the voltage first, DC alone will not do it.

[Stevo]

Thanks. Probably another dumb question so please bear with me...

What is the reason for even wanting to boost the 12 volts up to 18 or 19 volts when using a laptop? Is it because after the "loss" that the boosted higher voltage of 19 or 19 volts will draw less from your battery than if you started with an adapter that was only 12 volts - and then factored in the loss?

The other boost-converters you mention look fine to me. I only mentioned the Powerstream as one example of many. They ALL have loss. There is no way to take 12 volts DC and boost it up to 18-19 volts DC without loss. There is also no way to do the boost with pure DC current throughtout the process. There are no "magical" converters out there (like maybe Stamar is claiming?). All I've seen run around 90% efficiency that is far better then running a laptop with the AC-to-DC converter plugged into a DC to AC inverter. The biggest loss in that setup is the AC to DC converter that came with your laptop. Some are only 50% efficient. Used with an inverter you're talking about 60% loss to heat!

If your power-oultet or cigarette lighter has standard wiring - it will be rated 20 amps @ 12 volts. I.e. that's 240 watts. That power supply you showed a link for is rated for 85 watts.

[zero]

Thanks. Probably another dumb question so please bear with me...

What is the reason for even wanting to boost the 12 volts up to 18 or 19 volts when using a laptop? Is it because after the "loss" that the boosted higher voltage of 19 or 19 volts will draw less from your battery than if you started with an adapter that was only 12 volts - and then factored in the loss?

No. The electrical system in your camper is 12 volts. Runs up to 14 volts when the engine is running. Most laptops require 18 volts. That is the problem.. You have a 12 volt source and need to make it 18 or 19 volts to run your computer. Thus you need what is usually called a DC boost converter, i.e. it raises the voltage.

To be technical, the ignition system on the engine does kind of the same. Takes 9 volts when the engine is cranking and boosts it to 40,000 volts (more or less) to make sparks at your spark plugs..

[Maineah]

The power supply inside of a laptop does two things it charges the battery and runs the computer. The computer supply regulator is called a buck/boost the computer itself uses much lower voltages then 19 volts mostly in the 3.3 and 5 volt range that is the buck side. The battery uses a much higher voltages, the boost side like any battery in order to charge the voltage must be above the battery's rated voltage in electronics it is simpler to reduce/regulate voltage then it is to increase it. Yes the higher voltage requires less current. Bottom line the 19 volts is more so then any thing else to charge the battery. If you have a laptop and you do not need to charge the battery on it will work fine supplying 12 volts from your battery however that being said the effort in doing so really is not worth it the loss in a DC to DC converter is low enough that it is much simpler to use the DC to DC converter and just plug it in. Laptop batteries usually are some where in the 11 volt range.

[zero]

. Laptop batteries usually are some where in the 11 volt range.

I've got six laptops here. All have 18 volt battery packs. Toshiba and HP. What laptop has an 11 volt battery as you say?

[stamar]

Id like to see that put to the test, supplying the laptop with 12 volts through the power port.

[Derek up North]

I've got an old IBM A31 laptop. The charger reads 16VDC, 3.36A. The Li-Ion battery reads Nom 10.8V, 4.0AH. ASM PN 02K7022

I'll gladly sell you the laptop if you want to test it.

I'm too tired to go and squint at my old Dell D600 in the basement.

Happy New Year.

[Stevo]

I see. What is the point for buying an expensive DC boost converter over buying a $27 DC adapter like this one http://tinyurl.com/bdhvh28 that is designed for my computer?

No. The electrical system in your camper is 12 volts. Runs up to 14 volts when the engine is running. Most laptops require 18 volts. That is the problem.. You have a 12 volt source and need to make it 18 or 19 volts to run your computer. Thus you need what is usually called a DC boost converter, i.e. it raises the voltage.

To be technical, the ignition system on the engine does kind of the same. Takes 9 volts when the engine is cranking and boosts it to 40,000 volts (more or less) to make sparks at your spark plugs..