# Cigarette Lighter Laptop Adaptor

**URL:** <https://boards.straightdope.com/t/cigarette-lighter-laptop-adaptor/210066>\
**Category:** In My Humble Opinion\
**Created:** [October 28, 2003, 6:02pm UTC](https://boards.straightdope.com/t/cigarette-lighter-laptop-adaptor/210066 "2003-10-28T18:02:34Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![shelbo](https://avatars.discourse-cdn.com/v4/letter/s/3d9bf3/32.png) [@shelbo](https://boards.straightdope.com/u/shelbo)\
**Post date:** [October 28, 2003, 6:02pm UTC](https://boards.straightdope.com/t/cigarette-lighter-laptop-adaptor/210066/1 "2003-10-28T18:02:34Z")

</div>

Which is better, the cigarette lighter DC/AC adaptor, like [this](http://web1.applelaptopbattery.com/ccp5/cgi-bin/cp-app.cgi?rrc=N&pg=prod&ref=CAR%20ADAPTER)? So you’d go from DC to AC, then back to DC.

Or the straight DC converter, like [this](http://web1.applelaptopbattery.com/ccp5/cgi-bin/cp-app.cgi?rrc=N&pg=prod&ref=DC/DC%20ADAPTER)?

The AC version puts out 100 watts, the DC version puts out 70 watts. Is 70 watts enough for laptop usage? Any other considerations?

---

<div class="post-metadata">

**Author:** ![rickh57](https://avatars.discourse-cdn.com/v4/letter/r/54ee81/32.png) [@rickh57](https://boards.straightdope.com/u/rickh57)\
**Post date:** [October 28, 2003, 6:47pm UTC](https://boards.straightdope.com/t/cigarette-lighter-laptop-adaptor/210066/2 "2003-10-28T18:47:32Z")

</div>

It depends upon the power requirements for your notebook. My six month old Celeron based notebook wants at least 100 watts.

Rick

---

<div class="post-metadata">

**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\
**Post date:** [October 28, 2003, 6:56pm UTC](https://boards.straightdope.com/t/cigarette-lighter-laptop-adaptor/210066/3 "2003-10-28T18:56:33Z")

</div>

The step-up converter is _simpler_ than an an inverter+your existing adapter. Less things to fail and all that. There is also less power loss involved (less strain on the car battery). However, a cheaply made one is not better than a well made inverter. So the big question is how well are they made first, then pick the step-up converter if it’s just as good or better.

Wattage depends on _your_ laptop plus accessories. Since each one is unique, I can give no specific recommended number. Look in your documentation.