Portable Laptop Power supply

[redace001]

I'm looking into a DIY project or reasonable commercial product for creating a portable power source for running my laptop at a trade-shows. Typically they charge several hundreds of dollars for supplying AC power per show, and with my basic knowledge, it should be feasible to make a battery/voltage regulator/charger system that could save me big bucks over time.

I'd want to power the device for about 10 hours.
I know that my machine typically runs on 90w AC powersupply, putting out 19vdc.
What's the best route to take? Some ideas I've seen so far:
A deep cycle 12v marine battery + car adapter.

A 3pack of 6v gel cells + dc/dc voltage regulator.

commercial battery pack with AC outlet, (about 600Ah).

Thanks in advance for your insight and advice!

[pburgess]

Unless it's a MacBook, easiest would just be a few spare laptop batteries in your bag, and swap through the day. This would mean some intermittent down-time though.

I kind of doubt the local electricians union will take too kindly to your rolling in with a big ol' power pack. I've seen entire show setups halted over smaller issues.

[Zener]

Yeah, if you make your own AC they will probably just bill you for it... I concur on the idea of spare batteries. That will be cheaper and smaller than the alternative anyway.
As far as selling it as a product, you get back to the question of whether the union will allow anyone to use it. I don't think they will allow you to bring your own piece of carpet...

[MrGlass]

You could try this: http://revision3.com/systm/hackedups

[philba]

Another idea would be to get a UPS sized for your laptop. Charge it before hand and then just plug into it at the show.

[MrGlass]

Another example of someone doing this DIY: http://lifehacker.com/5898653/hack-toge ... ack-for-60