mobilehippo Posted January 14, 2014 Share Posted January 14, 2014 I know the topic sounds ridiculous..... I am working on a project where during the course of the day, I'll need to use my laptop to dump video footage on to my hard drive. I do not have a generator in my RV unfortunately. She's an old model didn't come with one. Has anyone ever charged their laptop using the reserve on deep cycle battery. The extent I've used my deep cycle battery is for cabin lights and water pump. What kind of appliances have others found possible to use on their deep cycle battery? Thanks! Quote Link to comment Share on other sites More sharing options...
WME Posted January 14, 2014 Share Posted January 14, 2014 What is the input voltage to your laptop? If its 12v your in business, if not you will need a pure sine wave inverter to run the AC charger. The truck will keep the coach battery charged. Quote Link to comment Share on other sites More sharing options...
mobilehippo Posted January 14, 2014 Author Share Posted January 14, 2014 Well when I plug the RV into the house I can plug my laptop in just fine. Oh I didn't know the engine runs the cabin power as well. But yes I guess that makes sense since the engine recharges the deep cycle battery... Quote Link to comment Share on other sites More sharing options...
stamar Posted January 14, 2014 Share Posted January 14, 2014 You need an inverter A cheap one will work fine dont need a sine wave Quote Link to comment Share on other sites More sharing options...
waiter Posted January 14, 2014 Share Posted January 14, 2014 As WME and Stamar have eluded;You should have an AC power supply for your laptop, Usually, this is a small black box with two cords coming out, One cord plugs into a wall outlet (110 Volt AC) The power supply box then converts this to whatever voltage is needed, and sends it out the other cable that plugs into your laptop..USE AN INVERTER.Inverters convert 12 volts DC to 110 volts AC. If your just running the laptop, a small 100 - 140 watt will do just fine. You can either wire the invert directly to your 12 volt system, or run the inverter off of a Cigarette lighter plug. You then plug your laptops power supply into the inverter and your good to go. DIRECTLY POWERED FROM 12 VOLT SYSTEMIf your Laptop uses 12 volts, you could wire the plug directly to 12 volts. This would be the most efficient way, but will only work if your laptop runs on 12 volts. I do this with a TV. It wasn't advertised as operating off of 12 volts, but after careful looking, I discovered it would operate directly on 12 volts. Heres how:Look on your laptops power supply for what the voltage "output" is. If its between 12-14 volts, your in luck. Now you'll need to find a plug that matches your laptops power plug. This can be a little more difficult as some laptops have weird plugs. When I wired my TV I knew I would never use the 110 volt power supply, so I just cut the cable off of the TVs power supply, and wired the cable directly to the 12 volt system. You MUST observe polarity (plus and minus) else you could destroy the laptop. I Used a voltmeter to check polarity on the plug before I cut the cable off.NOTE - Some laptop power supplies are multiple voltage (5 and 12) so these would not wor, and of course if the laptop runs off 18 volts (my Toshiba) this will not work.John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
Derek up North Posted January 14, 2014 Share Posted January 14, 2014 Or shop here:- http://www.ebay.com/sch/i.html?_trksid=p2047675.m570.l1313.TR0.TRC0.X12v+laptop+power+supply&_nkw=12v+laptop+power+supply&_sacat=0&_from=R40 Quote Link to comment Share on other sites More sharing options...
MontanaChinook Posted January 14, 2014 Share Posted January 14, 2014 So the simple answer is yes, with an inverter. How badly your coach battery will be drained after charging the laptop, I'm not sure. I'll be doing this quite a bit. And not moving much, so my alternator won't be charging the battery. I bought a pure sine wave inverter, and a 90 watt solar panel kit. I'm hoping that's enough to run my lights and charge my laptop and other rechargeable batteries for a couple weeks without having to start the truck. The real way to figure these things out is to measure how much power your device uses (not how much it claims to use, but e actual use), and test how much of a draw that is on your battery. So you figure out power usage and battery life, and go from there. But that involves a fairly steep initial learning curve to understand watts, volts and amps. People who are used to this stuff will say it's very simple, but I'll tell you that if it's completely foreign to you, it's not easy to grasp at first. I should have tested all my electrical use, then bought a solar set up which matches that use. Instead, I just looked at all possible power I'll use...LED lights, a 12v fan, whatever small amount of power my propane fridge needs, and then some computer and other battery charging. Probably pretty low power use...so then I just bought the highest watt solar kit I could afford and fit in the camper, hoping it will serve my power needs. So...maybe you're lucky and your laptop runs off 12v, but I doubt it. You'll probably want a true sine wave inverter, and you'll probably just find out by trial and error how long you coach battery will last. Quote Link to comment Share on other sites More sharing options...
Maineah Posted January 14, 2014 Share Posted January 14, 2014 Laptop batteries generally are around 2-2.5 amp batteries not a big load about the same as running one 1156 interior light bulb. You should be able to charge them just fine. Laptops usually have 19 volt input from the power supply I have experimented with laptops and what I found they will run on 12 volts just fine but will not charge the battery so you are stuck with having to use a 12 to 19 volt booster or an inverter if you want to charge your battery. A cheap inverter will work fine as long as you are using the laptop power supply it is a switching supply with good filtering and voltage regulation so it really does not care what powers it. Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted January 15, 2014 Share Posted January 15, 2014 you need an inverter. converts 12vdc to 110vac. most laptops use 18v dc - if you could find something that boosts 12vdc to 18vdc I would like to hear about it. Sure such a thing exists, I just do not know where. An inverter will allow you to charge cameras, razors & cell phones too. here is what I use: http://www.walmart.com/ip/COBRA-CPI-480-Cobra-400-Watt-Power-Inverter/11020914 Note that smaller inverters can plug directly into a cigarette lighter. This inverter can overload a cigarette lighter outlet - I actually melted some solder in one once. Instead wire the inverter directly too your house battery (a Circuit breaker is a good idea). Mine sets on the dinette chair which is right above the house battery. I used heavier wiring - I think it was 10 gauge. My inverter can run 2 laptops simultaneously. Note that the inverter will draw your battery down so you will find that you will need to recharge that battery if you use the inverter a lot. note that some will talk about pure sine & other higher end inverters. I have found that even though computers in general insist on such clean power, they are not needed for this application. Why? because essentially what we are doing is recharging computer batteries. The batteries drive the computer & the mfr has addressed such power needs. If you were running a desktop computer then I might not be so sure. Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted January 15, 2014 Share Posted January 15, 2014 let me add that if your house battery is wired to charge when the engine is running, you can run an inverter while under way. If you use a smaller inverter (150-200) watt you could get by running of cigerette lighter which would allow all alternator output to house battery to charge that battery instead of some driving the inverter. Quote Link to comment Share on other sites More sharing options...
WME Posted January 15, 2014 Share Posted January 15, 2014 you need an inverter. converts 12vdc to 110vac. most laptops use 18v dc - if you could find something that boosts 12vdc to 18vdc I would like to hear about it. Sure such a thing exists, I just do not know where. OK will this do? http://www.ebay.com/itm/DC-DC-12V-to-18V-5A-90W-Step-Up-Power-Converter-Shockproof-Waterproof-/301068578899?pt=LH_DefaultDomain_0&hash=item461915f053 Quote Link to comment Share on other sites More sharing options...
waiter Posted January 15, 2014 Share Posted January 15, 2014 Looks good. Depending how it up-convert, this would be a little more efficient than up-converting with an Inverter, then down-converting with the alp top powers supply.John Mc 88 Dolphin 4 Auto Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted January 16, 2014 Share Posted January 16, 2014 That reads like what would do the laptop computer. Curious how many amps input versus output - said another way if it outputs 4 amps how many input amps does it draw from your 12v dc battery? just looked at my power cord == 1.3 amp 110v ac & output 19v cd 3.95 amp. I am thinking the same as Waiter- rather than upconverting 12v dc to 110v ac & then taking that 110v a & making 19v dc..... still wonder how efficiently it up converts. shipped from hong kong. if you get it like to know how well it works. Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted January 16, 2014 Share Posted January 16, 2014 http://en.wikipedia.org/wiki/Boost_converter good write up on these things work Quote Link to comment Share on other sites More sharing options...
RVdaytrader Posted January 17, 2014 Share Posted January 17, 2014 I use a dc/dc converter to keep my laptop running all day. input is 11-15 volts and output 19 volts (what my laptop uses). Powerstream has an assortment. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.