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SabreKai · 01-06-2010, 16:01

I recently bought a laptop for navigation software and internet/email connection afloat. This beast comes with a 110v charger which puts out 19.3VDC (i forget what the wattage or current is) So my question is, how do I get that DC voltage from 12volt batteries? If I put two of them in series I can get 222-26v. But what do I use to step that down to the required 19.3V? Also how would I go about charging that? My panel is 12v. My charger for shorepower is 12V. Seems to me I'd be connecting and disconnecting batteries all the time.

Sabre

Ziggy · 01-06-2010, 16:17

The simplest and safest solution is to get a 12V DC charger for your laptop.

CharlieCobra · 01-06-2010, 16:21

That or a small inverter that plugs into a 12V socket. I use one I bought off eBay for $30.

marshmat · 01-06-2010, 16:22

Most laptop chargers I've encountered will work fine on a $40, 300-watt inverter. This is, however, not an efficient solution if you are concerned about the drain on your house bank, in which case a car-to-laptop charger is called for. These can sometimes be hard to find. Personally, I'd be more likely to make one out of a DC/DC converter and some filtering circuits.... but most folks would probably prefer to just go out and buy the thing.

Pyxis156 · 01-06-2010, 16:23

You will likely want to find a transformer for your laptop that can plug into a 12V outlet (like a cigarette lighter outlet in a car). Depending on the brand of PC, the manufacturer might already make such a beast, I have a Lenovo and they make an adapter that I use on our boat. If the manufacturer does not make a 12V transformer, you can check at a store like Radio Shack as I know they sell "universal" transformers that you can plug into multiple voltage sources, can set the output voltage, and select the appropriate tip and the polarity of the tip for your laptop.

stevensc · 01-06-2010, 16:40

There is an accessory made by "I Go" called I Juice. it comes with an A/c and DC adapters and you can buy tips which supply different DC voltages for computers, phones, portable radios etc.
I have one it works fine but I believe cost about $70.oo with assorted tips.
Got it at radio Shack probably available elsewhere also.
Here is the address www.igo.com
Good luck
Steve

AnchorageGuy · 01-06-2010, 17:19

the most efficient way to run a laptop is with a DC to DC converter found easily online.
DC/DC Converters, retail, wholesale, off-the-shelf and custom, DC/DC 5 watts to 1500 watts
much more efficient and will consume a lot less power than even the small inverters.

capt_douglas · 01-06-2010, 17:31

You're going to have to convert the boat 12V to what your computer uses. You've got 2 choices: (1) AC inverter; or (2) DC-DC converter. Losses will be about the same (converting 12VDC to 19.2DVC takes energy) but using the inverter is going to be less efficient than using the DC-DC converter (two conversions: 12VDC-120VAC, 120VAC-19.2VDC).

If it were my choice, I'd go with a good 300-400W true sine wave inverter. The losses will be higher but I can use the inverter for so many other tasks where the DC-DC converter is pretty much dedicated to the computer.

SabreKai · 01-06-2010, 18:00

Thanks for the replys. I'll have a look around for a DC-DC converter or a ready made car charger. I'll have to get on with the manufacturer by phone n see what they have.

Sabre

pumpcity · 01-06-2010, 18:05

There are a lot of 12 VDC chargers for laptops on Ebay. Just type in 12 VDC and the name of your laptop and see what happens. I have one for my car to charge my Dell laptop.