Best way to power laptop?

**spdyscotty** · 07-10-2005, 12:10 AM

Hello, I have a Compaq Aramada E500 to be used as my carputer. I bought an inverter to make use of the AC adaptor that came with the computer. Unfortunetly it does not survive crank.

A also purchased the micro shutdown controller to be used to automatically shutdown / turn on the laptop. I plan on soldering to the power button inside the case. Since my inverter does not surbice the crank, is there going to be an issue when trying to turn the computer on from the shutdown controller I bought?

I recently came to the realization that I could have simply used a DC car adaptor (~$25 on ebay) to power the laptop. Is this a better option?

I need a way to power this baby that will be compatable with the shutdown crontroller. If the shutdown controlled would have a short delay before sending the "on" signal I think it work work. I havent wired it up yet; so I'm not sure.

What do you guys think I should do?

**ACHIEVER** · 07-10-2005, 01:24 AM

Originally Posted by spdyscotty

Unfortunately it does not survive crank.

Don't you have a battery in the laptop? This is one of the best things, IMO, about using a notebook in the car. It already survives crank because of the built in "tank" circuit...ie battery.

Also I think the DC-DC car adapter is far more elegant than using an inverter.

**spdyscotty** · 07-10-2005, 02:04 AM

Nope, no battery.

I just wired it up directly to the battery (rather than using the DC plug in the car) and it worked perfectly. It actually survived crank to my surprise.

I guess I'm going to just use it this way. If I have any issues with the inverter I'm going to buy a DC car adaptor.

**spdyscotty** · 07-10-2005, 02:06 AM

If I used a DC-DC converter, would I have less a chance of surviving crank?

**KyleYankan** · 07-10-2005, 02:11 AM

yo uwould have a much better chance. the DC-DC transformers are MUCH more efficient. I mean a good ivnerter is 90% efficient, and a good laptop charger is 80% efficients.

.9*.8 = .72

That means your 72% efficient. For every 72 watts of power your laptop needs, you'll draw 100 watts from the battery. the other 28 watts become heat.

**damado** · 07-10-2005, 01:14 PM

I am also looking for a power adaptor for a laptop.

So far I've found these two that seem to be good quality. Which is best?

This one?

Or this one?

Edit: nm I went with the OEM IBM DC-DC adapter.