Mobile Power Supply?

TrumandrummerTrumandrummer Taylor Michigan Icrontian
edited March 2008 in Hardware
Not sure if the is the correct place to post this, but im going on vacation to Florida for school and its a 24 hour bus ride.

Im planning on bringing my lap top, for movies, games etc....

My battery lasts about an hour just browsing the net...
I looked up Universal External batteries and found some that claimed to last 11 hours. But will probably last around 3 while watching movies and stuff.

So I started searching mobile power supplies and found some interesting stuff.
Basically a huge battery able to charge stuff and even jump start cars. The thing is, it doesn't really say how long it will last and im not the greatest with doing the math on currents and power or w/e.

heres a link to one I was looking at http://www.amazon.com/Xantrex-Powerpack-Jumpstarter-Inverter-Backup/dp/B000E6LEIC

I was just wondering if anyone could help me out with this, or maybe someone has past experiences with products like this to tell me how good they work.??

Comments

  • mmonninmmonnin Centreville, VA
    edited March 2008
    Might as well bring a car battery...cause thats basically what you're asking for if your lappy is that power hungry.
  • muddocktormuddocktor
    edited March 2008
    Yeah, for that kind of money I would buy myself a deep cycle RV/boat battery and a 100-150 watt inverter and build my own portable battery system. That one you linked shows that it only has a 28 amp/hr battery in it. That's more a motorcycle or riding mower sized battery. With a regular deep cycle battery I would think you would get 12+ hours runtime at least.
  • edcentricedcentric near Milwaukee, Wisconsin Icrontian
    edited March 2008
    Do you own a UPS? we used to buy the sealed lead acid batteries that were used in UPSs and then take the standard charger from HP that will handle a 12V input. A little custom cable work and bingo.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    that UPS is actually a really good idea :D. Where would you buy a bettery like this,

    how long did it last?
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    Also how much will a boat or rv battery cost me?
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    Turns out, my UPS doesn't last long soooo thats out.

    The rv/boat battery sounds very good...
    And it just so happens that I have a power Inverter, and a boat battery

    Any estimate on how long it will last, if I use it to run my laptop without the battery in it. That way its just running the laptop and not trying to charge too.

    Because I could go buy another battery, then I would have 2
  • beatzbeatz i am a hamburger Member
    edited March 2008
    Do you have the capacity of your laptop battery in mAh and the capacity of the boat battery, most likely in Ah ? For better accuracy, can you figure out how much capacity your laptop battery still has, when its fully charged, or just try to remember how long the battery lasted when it was new and use the design capacity of your laptop battery.

    Example:

    boat battery: 80Ah
    laptop battery: 4000mAh = 4 Ah

    boat / laptop equals 20. So you get 20 times the battery life.

    Okay, let's not forget the inverter. It will give you an efficiency of 90%, that leaves 18 hours.

    It's important, that you have a sine inverter, not a trapezoid inverter, if you plan to use your regular laptop power supply. Trapezoid may break it. Even better to convert directly from battery to laptop voltage with a car adapter, assumed your boat battery has 12v.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    Well I havn't looked at the stats on the boat battery yet but I did gather up my power inverter and the hookups to plug it to a battery.

    Im not sure what a sine or trapezoid means
    It says it converts 12V DC to 110V AC
    runs from vehicle or directly from battery
    400 Watt, 800 watt peak
    and the brand is Vector

    The battery is in a case, inside the boat, and I had my dad charge it so that I could do some testing with it. But he said it will charge overnight, So I will look at the stats of the battery tomorrow.
  • beatzbeatz i am a hamburger Member
    edited March 2008
    Take a look here.

    Basically it depends on the quality of the inverter. The cheapest ones have a square output, better ones a trapezoid, also called modified sine, the best ones have a sine output, which is the type of ac you have from your wall plug.

    You'll need at least a trapezoid signal for a laptop power supply. At first I thought it needs a sine, but a trapezoid i.e. modified sine should suffice. I was looking into putting an inverter into my VW T4.

    Anyways, as for efficiency it would be best to to use a car adapter directly with the battery without the inverter, that's what I am doing in my car now. Also, be aware that shorting that kind of battery is pretty dangerous.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    how would i hook it up to the battery without an inverter?

    And i figured it was dangerous,I was planning on being carefull


    Is there anything dangerous that could go wrong, besides like human error?
  • beatzbeatz i am a hamburger Member
    edited March 2008
    Without an inverter it's possible if the battery has 12v and if you have a car adapter for you lappy.

    Anything else dangerous? Hmm, maybe you could hurt yourself because the battery is so heavy ;) .
  • muddocktormuddocktor
    edited March 2008
    If you have a car adapter for your laptop, it should be easy to rig up a power connector (lighter socket) to a couple of alligator clips for easy hookup to the battery.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    So basically im looking for this...
    http://www.apexbattery.com/universal-universal-laptop-car-adapter-dc-dc-90w-.html

    And I could cut off the lighter plug and seder on some alligator clips. Is that what your saying?

    I found a 115ah boat battery for 70 bucks at auto zone with trade-in of an old battery. And I don't think my current boat battery is good because its really old. So I might do that because its a lot cheaper that what I have seen online.
  • EssoEsso Stockholm, Sweden
    edited March 2008
    Have you asked if you can be placed behind the driver, using the 12 V plug.
    In that case you wouldn't need the heavy battery onboard.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    The problem with that is that me and my friends want the back for multiple reasons.....

    1. The teacher sits up front
    2. Its a charter bus, so the back seat has two seats facing each other for all my friends.
    3. There is a table in the middle of the two seats where we will set up speakers and, play games etc..

    Although it isn't a bad idea
    I guess if I run out of power or something goes wrong i could switch seats with someone.
  • drasnordrasnor Starship Operator Hawthorne, CA Icrontian
    edited March 2008
    It is very unlikely that your teacher will let you have a battery like that on the bus. Wet lead-acid batteries give off explosive hydrogen gas during charge/discharge and will spill acid if tipped over. You won't be able to afford any other type.

    -drasnor :fold:
  • CBCB Ƹ̵̡Ӝ̵̨̄Ʒ Der Millionendorf- Icrontian
    edited March 2008
    Don't the nice charter buses have 12v ports at every seat anyway?
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    Well, we went 2 years ago and they didn't have any type of plugs or anything, and they were really nice charters too...

    My band teacher is actually a really cool guy, he wouldn't care either way
    So if I sit in the back and keep it out of site from the driver ill be good. I already got a way of sneaking it in. and im gonna be careful with it, I know its a hazard.... there is always a hazard when it comes to electricity:D
  • beatzbeatz i am a hamburger Member
    edited March 2008
    What about making an extension to reach trough the bus from a male and female plug and some wire? Actually buying an extension and just extending the cable would be easier. An extension like that could come in handy in other situations as well.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    Thats a good idea

    And I might do something like that, but I still want to do the battery thing because, what if the bus driver doesn't want me to do that?
    Idk, some bus drivers are really picky, and rude

    So I still need a battery as backup...
  • drasnordrasnor Starship Operator Hawthorne, CA Icrontian
    edited March 2008
    I can't imagine that you'll be on a bus for a solid 24 hours. In my experience, the bus driver will refuse to drive more than 8-12 hrs a day. You'll be stopping every few hours for people to get up and move around. Odds are the places you stop will have electricity that you can use to charge your laptop. I can get a solid 60% charge into my laptop's battery in about 10-15 min.

    What you should be doing right now is figuring out your laptop's power consumption. Go download mobmeter and keep track of your average power usage as you try to perform the tasks you want to do on battery. Mess with your power settings, turn down your backlight, step your processor and graphics down to minimum performance, and turn off the wireless radios to save power. Mobmeter will tell you the wattage you're using in real-time so you can compare that versus your battery's current (NOT rated) watt-hour capacity. I say current because lithium-ion batteries lose 10-15% of their capacity per year. It's straightforward division from there to figure out how many hours of runtime you're going to get.

    Also consider bringing some other things to do. My Nintendo DS can do about 18 hrs of playtime on a single charge. Bring some cards or a board game. Share bull**** stories with your friends. Sing. Because as awesome as your teachers are, there is no way you're going to get a 60 lb bulky fire and chemical hazard onto a bus.

    -drasnor :fold:
  • the_technocratthe_technocrat IC-MotY1 Indy Icrontian
    edited March 2008
    Take the opportunity of the forced close proximity of female co-riders and see if you can get your floppy loaded.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    well the last time we went, we did stop a decent amount of times but it was literally 10 min, and my lappy doesn't get even close to charged in 10 minutes.

    Occasionally we would stop and get food, and then I would be able to charge my lap top.

    But I have done all the changing of stuff like screen brightness and stuff, and it still lasts about an hour and a half to two hours when browsing the net

    Now if I was watching a movie, the time might decrease a lot...... and then Id be going about 6 hours at least with no power, or a place to charge...

    But I will deff try out that mobmeter,
    turn everything down, and run a movie and see how long it lasts....

    Im probably gonna ask my teacher what company bus is taking us, and I think im gonna call them and ask if they will have any way to supply power (lighter outlets etc..) But last time, they didn't have anything.



    EDIT: another thing I was thinking of, with the idea of using a long extension for a cigarette Lighter
    I don't think, that charter buses will even have cigarette Lighters even up front, because isn't it like a law that you can't smoke on these buses?
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    the_technocrat wrote:
    Take the opportunity of the forced close proximity of female co-riders and see if you can get your floppy loaded.

    Lol, problem is..... this trip is for marching band, and we got rid of the pom...

    No good looking girls
  • BuddyJBuddyJ Dept. of Propaganda OKC Icrontian
    edited March 2008
    Read a book.
  • the_technocratthe_technocrat IC-MotY1 Indy Icrontian
    edited March 2008
    Trumandrummer wrote:
    Lol, problem is..... this trip is for marching band, and we got rid of the pom...

    No good looking girls

    so they're desperate...
  • mmonninmmonnin Centreville, VA
    edited March 2008
    drasnor wrote:
    I can't imagine that you'll be on a bus for a solid 24 hours. In my experience, the bus driver will refuse to drive more than 8-12 hrs a day.

    Its flat out against the law to drive that long. Truck drivers can drive like 10 hours in a day, but some keep 2 books so they drive longer anyway.
  • TrumandrummerTrumandrummer Taylor Michigan Icrontian
    edited March 2008
    they stop and swap drivers half way through
  • beatzbeatz i am a hamburger Member
    edited March 2008
    Let's look at some alternatives :bigggrin:

    ws48a1.jpg
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