Compact, lightweight source of 12V DC for junk yard excursions - What are my options?

I was thinking it would be cool if I had a compact and light-weight 12V battery of some sort to bring with me on junk yard excursions so that I could power-up an entire car, or individual electrical bits bits (like, "gee, I wonder if this power window switch works").

Is this a thing?

http://www.harborfreight.com/12-volt-jump-start-and-power-supply-38391.html

A 12v SLA battery is what you're looking for, I think. I wouldn't try to start a car on it, but they might be beefy enough to juice a power window (I'll leave the math to another part of the hive mind).

I bet that's what's in that HF jump box, and it already comes with the charging bits and leads...

You want lithium tech if you don't consider an actual box full full of lead "lightweight".

I've got a 12v DeWalt cordless drill I use the battery from to roll up power windows and such. An 18v works fine also.

what you want is this: Cobra-Jumppack

I have used one of these to move a power seat:

It is from my dremel/flashlight, so it is small.

Not much serious moving power.

I have borrowed full size car batteries from the desk to test bigger things, they allow it as long as I brought the battery back and didn't set anything on fire.

Most yards are not fond of you bringing your own power, which is why the small drill batteries work; pocket sized. If you need more juice, just ask, they usually sell used batteries so many just sit around.

peter wrote: A 12v SLA battery is what you're looking for, I think. I wouldn't try to start a car on it, but they might be beefy enough to juice a power window (I'll leave the math to another part of the hive mind). I bet that's what's in that HF jump box, and it already comes with the charging bits and leads...

The battery in most of the jump boxes is a SLA battery. I've got an older Mighty Mite jump box that uses a 12v 12ah SLA battery, I replaced the battery and charger in it last fall. It has started countless vehicles, and kept cell phones charged during extended power outages. It's not super light weight though ~10 lbs, and takes forever to charge, about 10 hours to full from completely draining it.

Zippy 4s2p 8400 mAH Lithium Iron Phosphate battery.

2.2 lbs, $85, will start an LS1.

http://www.harborfreight.com/18-Volt-NiCd-Replacement-Battery-68860.html

or

http://www.harborfreight.com/12-volt-multifunction-power-tool-lithium-ion-replacement-battery-68059-8109.html

plus a 25% off coupon from here: http://slickdeals.net/f/1276399-harbor-freight-coupon-thread

Thanks for all the suggestions guys.

Saw this thread recently and remembered it going to the junkyard Saturday. Took along an 18v Ryobi battery. Worked great moving windows and power seats!! Great idea.

(8) D Size (Rechargeable) Batteries in two cheap plastic holder packs, two leads with alligator clips or probe tips. Find a little bag or container that fits with your junkyard tool kit.