car adapters for r31 are they safe?

[awong]

i was browsing ebay and saw this,
http://www.howardforums.com/showthread.php?t=1224854
still consider myself a laptop noob, but just wondering are they save to use the car adapters? or a is spending extra on a second battery a safer thing to do instead?

[rkawakami]

Not sure what the Howardforums link has to do with a DC-DC adapter, but if you are talking about something like this:

eBay listing for 72W AC/DC Combo Adapter

then yes, they are safe to use with the laptop. If you were referencing a "universal" DC adapter then what you have to worry about are the following:

- proper polarity of the plug
- proper voltage being supplied
- maximum amount of current provided by the adapter at the voltage required by the laptop

[awong]

sorry about the incorrect link wrong copy paste.
this was the original link I was using
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0142995420
it says car charger, I am assumming with car charger only, its not meant to be used with the laptop on at the same time like say to watch movies on a long trip.

Moderator edit: Shortened URL to prevent horizontal scrolling

[rkawakami]

If that's the actual picture of what they are selling, then it looks like a "universal" adapter. There appears to be a sliding switch on the end of the adapter. Something like that is normally used to select the output voltage. Yes, you can set it to 16V, but if there's a higher setting you stand a chance of damaging the laptop if that switch gets accidentally moved.

At that price ($25) you could probably get an original IBM 22P9003 AC/DC Combo adapter as shown in the link I provided earlier, or just a regular DC converter. Search eBay for that part number and you'll find some. Be sure that they provide the DC cord. And, no, if the specs are to be believed, it provides the 16V and 4.5A that will allow the laptop to be fully operational, not just being charged. An alternative to a special car adapter would be to buy a DC-AC inverter which converts the 12VDC in your car to 110VAC. That way you could simply plug in your regular AC adapter (and other AC-powered equipment up to the current rating of the inverter).

[allan]

Thanks to Hurricane Dean I had no power the last two days and have been using one of those 12v DC- 110v AC adapters with an extension from the Land-Rover to my office to run the laptop, phone and modem. It was about half the price of the IBM car adapter and obviously much more versatile. Also watched TV in the dark in the evening.