Car adaptor for laptop

Emerson · 10-16-2005, 11:29 AM

I'm wondering if I could connect my Thinkpad directly to the cigaret lighter socket. Does anyone know what good does the dedicated adaptor? Those output usually 14-18 V, however, laptop internal battery is only 10.8 V. Logically thinking the car voltage 12.5-13.8 V would suffice... without any converters?

davcefai · 10-16-2005, 02:27 PM

I suggest extreme caution here. The supply from your cigarette lighter is unfiltered and unsmoothed and the voltage may vary unacceptably.

You will have noise due to the ignition, surges and spikes when the load changes (for example turning on the lights or the a/c compressor cutting in)

The adapter should sort out all this despite the price being probably a rip-off.

Emerson · 10-16-2005, 03:41 PM

Thanks. Good point. Probably the voltage is not going to drop too low, but release of a powerful electromagnet like the one on A/C compressor may induce harmful impulses. Maybe I should go with an universal DC/AC converter and use the regular AC adaptor to feed my laptop. Still cheaper than that IBM-ish car adaptor ($130).