power for my laptop

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willh2o

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Nov 27, 2016
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My Dad doesn't like me to use the generator to power up my laptop batteries, yet likes to dry camp for several days at a time. Any suggestions? We have bought 3 inverters that quickly die. I have extra laptop batteries that I try to keep charged up, but even so run out of power.
 
Depending upon the required input voltage of your laptop you could get a stepup or step down converter and power it straight from 12v. You'll need a cigarette lighter plug, wire plus the appropriate plug which fits the laptop (try Radio Shack if you can find one open). Much more efficient than converting 12v to 120v with the inverter then back to 16-19v (or whatever your laptop needs) with your AC adapter. However, it will still be drawing power, somewhere in the 3-4 amp range. The laptop uses power, no way around it.
 
While it is true that you can take a 12V input from a cigarette lighter plug and create 5V to a USB port, not every PC can be charged from a USB port. You might want to use a tablet instead which can be charged this way, perhaps one with a wireless keyboard. I had heard that some Fujitsu PCs have USB C ports that might work this way, but I have not tried it.

Does you Dad's RV have a built in inverter?  These inverters sometime provide power to one or two plugs in the RV. 

If you don't want to use a cigarette lighter plug you could connect one of the adaptors in the link below to a 12V lamp socket or switch and have a couple of hard wired USB ports to charge a tablet.  I have seen small inverters, but I cannot vouch for their reliability. 

https://smile.amazon.com/gp/product/B00OTPFK34/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
 
JoelP said:
While it is true that you can take a 12V input from a cigarette lighter plug and create 5V to a USB port, not every PC can be charged from a USB port.


This is true. My suggestion was to use something like this:


https://www.amazon.com/uxcell-Converter-Regulator-Transformer-Waterproof/dp/B01N4109JD/ref=sr_1_1?ie=UTF8&qid=1499483757&sr=8-1-spons&keywords=12v+to+19v+converter&psc=1
 
If your notebook happens to have an 18VDC input (fairly common, but some are higher and some are lower) you might check this out http://www.ebay.com/itm/High-Effciency-100W-18V-Foldable-Sun-Solar-Panel-Grid-kit-Power-Bank-for-RV-Boat-/302321655914?hash=item4663c6606a:g:BU4AAOSw9OFZHsYO

I don't really like the idea of connecting a solar panel directly to a notebook for charging, but you might get away with it.

I would prefer to use solar panels to charge the RV batteries, then a cig lighter style DC power adapter to charge the computer.  (not an inverter and the standard AC power adapter)
using a kit like this:
http://www.ebay.com/itm/Semi-100W-Flexible-Solar-Panel-Class-A-Kit-for-boat-caravan-motorhome-camper-USA-/172221368820?hash=item28193189f4:g:BDoAAOSwepZXSGNc

or
http://www.ebay.com/itm/160W-12V-Mono-Solar-Panel-Off-Grid-Kit-20A-CMG-Battery-Regulator-for-RV-Yacht-/302284632453?hash=item4661917185:g:vJ8AAOSwmgJY8U~7

wired to the RV deep cycle battery

then something like this for the notebook computer

http://www.ebay.com/itm/PWR-CAR-CHARGER-FOR-DELL-19-5V-4-62A-90W-LAPTOP-DC-ADAPTER-POWER-SUPPLY-CORD-/221075465001?epid=1131766302&hash=item33791fe329:g:UdcAAOSw-0xYVHl5
of whatever voltage is appropriate for your specific model
along with something like this

If you share the brand and model of notebook computer with us we may be able to give more specific advice
 
Many many years ago those car chargers cost $200 instead of $19
 
Two suggestions in fact.....

Some companies, I-Go is one, make 12 volt to computer voltage up-verters, Charge it direct off 12 volts.. I have a couple of 'em lying about  I do not often use them but they do come in handy (The reason I do not use them is a bit complex).
This Amazon page shows many such devices

NOTE: not all computers need the same feed, Some need more current or less (If you plug a 3 amp charger into a computer that only needs 2.5, no problem, the other way around Problem)

Some use different voltages,, That MUST match  My HP's for example are 19, not sure of the Toshiba.

Next is a better inverter.. Say a Samulux 300 pure sine wave.

 
We have bought 3 inverters that quickly die.

Could you elaborate a bit more on this?  Small inverters are common and not expensive these days, and quite reliable too. Did you mean the batteries die (insufficient charge) so the inverter stops supplying power?  I would think an extra 12v battery or two would handle your computing needs for several days.  Or plug the inverter into the car/truck (with the engine running) occasionally for some charging.

You didn't mention how much time you need daily on the laptop. Are we talking an hour or two, or maybe you use it all day for entertainment as well as email and some web surfing?
 
Inverters waste power.  Most major laptop companies make 12 volt cigarette lighter power adapters. Go look for one of those for your make/model.
For boondocking I switched everything in our rig to run off 12 volts except for the microwave and AC.  I installed additional 12 volt plugs throughout the RV.
Nothing goes in it unless it will run directly from the batteries. We even use a stove top percolator for coffee.
 
Old Radios is right about the reduced efficiency with an inverter (about 10% loss), so a 12v adapter for the laptop is the best bet. But whether using inverter or adapter, the battery is still the critical path.
 
willh2o said:
My Dad doesn't like me to use the generator to power up my laptop batteries, yet likes to dry camp for several days at a time. Any suggestions? We have bought 3 inverters that quickly die. I have extra laptop batteries that I try to keep charged up, but even so run out of power.

Have you tried just not using the laptop , and get out and enjoy nature?
 
Thanks for all the comments. I will share all of the suggestions with Papa who is an engineer and has an electrician license....

Here are a couple of answers to questions posed in your comments.

Our 2004 Itasca does have an inverter, but only seems to work for the TV. I plugged a surge protector in and the only thing that works is the TV.

I have a Lenovo x230 tablet.

Thanks again,
Sandra

 
In response to Gary's questions. The 3 inverters we bought from Amazon totally died after using them a few times.

My preference is the use my computer for lots of things, emails, business, photo management... The batteries take quite awhile to re-charge and don't stay charged for very long.

I have 2 extended ThnkPad 67+ (6 cell) batteries as well as the smaller battery that it originally came with.
 
Gary RV_Wizard said:
Old Radios is right about the reduced efficiency with an inverter (about 10% loss), so a 12v adapter for the laptop is the best bet. But whether using inverter or adapter, the battery is still the critical path.
If laptop is similar to mine, charger output is 18VDC which would require a DC-DC converter to use the 12VDC RV battery. What that means is it has the same inefficiencies that an inverter has plus some. It has to convert/chop 12VDC and step it up to allow the inverter section to produce 18VDC. The TANSTAFL principle.
Only solutions are more batteries either for laptop or RV with a quality inverter to produce needed power for laptop. Add a solar power charger to your existing battery system to add a little more power.
Look at moving over to a tablet which has lower power overhead and will operate much longer on less power and less load on RV battery for charging.
 
There are 12v car chargers for Thinkpads on Amazon at reasonable prices,$20-$30 deepening on the model needed.

I can't imagine 3 inverters failing like that unless something is wrong with the power source, but not having seen them I cannot even guess. Certainly many of us use them. But the key remains the amount of battery capacity the RV has - or Papa is willing to add. The watts of power has to come from somewhere!
 
Gary I can see low end inverters failing like this, at my previous work we issued notebook computers with these small lighter socket powered inverters to our salesman who typically spent 4-6 hours on the road each day going from customer to customer.  Under this sort of daily use those cheap inverters would typically last less than 6 months.
 
Unfortunately for me, Surface Pro has not as yet developed an alternative charger for their proprietary plug. I'm stuck with the socket inverter to the 120v plug which I use on the motorcycle.
 
I run solar and a lot of batteries and inverter on our tow vehicle for our rig. However, when we are travelling and end up with a quick overnight somewhere (rest area, Walmart, truck stop, etc) I didn't want to have to take the time to hook up the truck to the trailer, so I purchased a plastic tool box from Home Depot and set in a couple of ES 12-12 batteries in series, a Samlex 24 volt 300 watt pure sine wave inverter, and an inexpensive wheelchair style 5 amp 24 volt charger. The 12-12's are in a plastic box inside the toolbox, and I mounted an XLR connector port for the charging, and a 50 amp Anderson Power Pole connector for the output to the inverter. So in round numbers it's 12 amp hours at 24 volts (or 288 watts). We run laptops, charge cell phones, grind coffee, sometimes run a floor fan off of it. It's portability is a key benefit, just grab it and go. Simply plug it in to 110v when it's available. You could run your laptop under a shade tree anywhere! I don't have a picture of it, but could if you want to see it.
 
If you want one now and do not want to order it, Radio Shack has the small to large inverters that work well. I got a 1000w and it lasted me 5 years of heavy  use
 
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