I'm a Slime pump user too. Mine's an older model, I think it's been superseded by a newer one. I took mine out of the housing like others on here have mentioned; there's a lot of wasted space inside those pump cases. In my case I built a new housing so the pump would fit into my tool tube. Mine runs off a pigtail attached with a fused connection directly to the battery. I used 14 gauge wire and a 15 amp fuse, if I recall correctly, to make the pigtail, and I rewired the Slime pump with 14 gauge wire to replace what looked like 18 or 22 gauge zip wire that it came with. I also took the pressure gauge off; it was just more wasted space, and those little stick gauges they sell for a buck at the auto parts store and will fit in your pocket do just as good a job.
I've tested my Slime pump both for inflating a tire from totally flat to full, and also for setting the bead on a tubeless tire, and that little cheap pump worked just fine. I go along with EricV on this; the $100 pumps are very nice and definitely better built, but that Slime pump does the same job at a tenth of the price. I might spring for the pricey one if I was heading to Patagonia and beyond the reach of any help, but otherwise the cheap one works for me, and I've been using that one for years.
This is the one I bought. I think back in 2009. It's fairly small, but it still took up too much room in the top case.
This is still the same Slime pump, just with a new housing and some of the components moved around.
