12V Laptop Charger

[arjand]

I am looking at 12V laptop chargers and I am looking at USD 40 vs HP Pavilion DV5-2008, DV5-2008CA, WQ795UA Series Laptop Auto Car Adapter USD 110 http://www.lindelectronics.com/cgi-bin/store/shop.cgi/!ORDERID!/aaa/Hewlett-Packard/dbx_gen_mfg_products?industry=.
I assume it is the same old penny wise pound foolish again but cant stop hoping... Does anybody have any experience in this field?

[callmecrazy]

I'm not sure what the difference is, but I have one without the box connected. Just the straight plug from 12v socket to laptop. I have the same thing on 2 different laptops and they both work great.

That HP one seems like overkill (whatever that box is doing), but I don't know the specifics of your requirments.

[callmecrazy]

"PWR+ dc adapters are made with the highest quality materials. Laptop safeguard features against incorrect voltage, short circuit, internal overheating. 100% compatibility with the original."

I guess that's what the black box is doing... Personally, I don't worry about it much, and mine has been running fine for the last six months of the straight 12v dc-dc converter plug (like in your second link).

HP, and I'm sure a few folks around here, would probably recommend you get the one with the protection features.

[colemj]

The charger in question is a DC-DC boost converter to supply 19V from a nominal 12V source like a car or boat. The box is doing this function. If you have a computer that runs off a voltage different than 12V, then you need a boost converter. If you do have a 12V computer, you may get along fine plugging it straight into a 12V nominal source, but you aren't doing yourself any favors. Much better to get an inexpensive dc-dc converter to regulate the voltage. They can be had for less than $10.

Mark

[rebel heart]

There are DC-DC converters out there but very few of them can handle the type of voltage fluctuations that are present in a boat (or car). If you look at DC-DC power supplies for the mini-itx class of computers, you'll see costs in the $40-$80 range that are capable of handling wide inputs. Not that any of us would let current drop to below 12v, but going over 14v is easy during charging.

If you're buying a DC-DC adapter for less than $40, you can safely assume it doesn't have the higher end components necessary to create a pure 12v with a wide range of input fluctuations.

The better DC-DC power supplies (for hardwired solutions like mini itx) take it a step further and accept voltage from 6v-24v, as well as offering jumper positions for things like "send a shut down signal to the mother board when voltage is below 12v for more than 1 minute", etc.

[sy_gilana]

IF you are going to power a DELL, the laptop will not run full speed with a "foreign" power adapter.

[abh]

Since when was a voltage regulator an expensive component?

[PyotrBee]

Originally Posted by sy_gilana

IF you are going to power a DELL, the laptop will not run full speed with a "foreign" power adapter.

Not quite.. this can happen with Dell adapters too. Dell has 2 common wattage (and some rarer higher ones for XPS systems). The 2 common ones are 65w and 90w.. plug a 65w into a 90w computer and it will sense this and slow down to reduce power usage.

Dell chargers have THREE connections. +19v, gnd, and a serial signal cable which is used to read a chip in the adapter to determine if its genuine (to force you to buy a more expensive Dell part, although a few third party adapters have figured this out now), and also communicate the wattage capability of the adapter. This is actually done on the center pin which is a bad idea for a variety for reasons, but the wattage idea is good. The voltage and ground are the outer shroud and an inner shroud which is separate (although not obvious) from the outer shroud.

[pillum]

I have an iGO charger that I use for my Dell on the boat. It cost almost $100 but it's multi-use from 12VDC or 100-240VAC input, with a bunch of output adapters. Though I specifically bought it for my Dell because of it's sensing capability, I also use it as a common charger for many other electronic equipment on board. Ensuring that electronic equipment works properly is something I wouldn't go cheap on. JMHO.

[rebel heart]

Originally Posted by abh

Since when was a voltage regulator an expensive component?

Tell that to the guys building DC-DC power supplies for laptops that don't work with variable voltage. You'll find tons of negative reviews floating around amazon for this very problem.

[abh]

My comment was actually aimed at them, you saying they don't read this forum?

[mikefossl]

I'm using a Rocketfish 100v-240v /12v power adapter for my Panasonic Toughbook. It seems to work well and includes a USB charger for my iPod and cell modem. It works well and uses less power then plugging the stock adapter into an inverter. Make sure one of the available tips matches your computer.


Amazon.com: Rocketfish RF-PRACDC Travel Laptop Power Adapter: Electronics

[Bryan Kemler]

I am not an electrician, but I take a lot a lot of 12volt chargers apart in order to connect things like my ROKU and old Apple TV to my LCD monitor, so kids can watch videos at anchor. I would buy the cheapest one. In fact, I would go to Radio Shack and buy an Enercell for $25.