Has anyone let their robot vacuum loose in the garage?

I run mine out to the garage a couple times a month in the summer, same situation, smooth sealed slab with a transition lip at the door. A little clack going down an edge is normal. The drop itself isn't what hurts them, it's the nose-diving at speed. Most robots have drop sensors near the wheels that are supposed to stop the brushes when the front hangs over an edge, but on a shallow lip like yours the machine basically just thumps down and keeps going. Mine has done that for two seasons with no wheel issues. What acutally kills wheel motors is grit working into the bearings, so on sawdust days I flip it over and pull the wrapped fuzz off the axle ends when it's done. Takes two minutes.

If the clack bothers you or it's bouncing hard enought to throw off its navigation, lay down a cheap transition strip or a ramp shim so the descent is gradual. That solved it for me. Also check the underside of the lip for a raised seam or old caulk bead, because that's what usually causes the hard contact rather than the drop itself. On temperture, your instinct is right but the threshold matters more than the season. Lithium packs genuinely don't like sitting charged in freezing temps, and charging a cold battery is worse for it than running one. The rule of thumb I've settled on: if the garage is going to sit below freezing overnight, don't leave the dock out there. Charging a battery that's internally cold can cause lithium plating, which permanently cuts capacity.

So the practical setup is run it in there from late spring through early fall with the dock in the garage, then before the first real cold snap move the dock and the vacuum back into the house and let it live somewhere above about 10 degrees C. If you only want it in the garage occasionally during a shoulder month, just carry the machine out warm from indoors, run it, and bring it back in rather than letting it cool off out there between runs. Store it around half charge if it's going to sit a while, that's easier on the cells than leaving it topped up.

One thing I'd check before letting it loose out there is the weatherstripping on the bottom of the garage door. Mine drags a rubber seal that sits proud of the slab and the vacuum hates it way more than any floor transition. It gets hung up, spins in place, and eventually throws an error. Took me a few trips out there to figure out what it kept getting stuck on. Also, on the cold side of things, watch out for condensation. Bringing a robot that's been sitting in a cold garage straight into a warm house'll fog up the sensors and the inside of the dustbin lid. Let it warm up to room temp before you dock it or run it, same as you would a laptop.

Been running robots since the days when you had to schedule them with a clunky IR remote, so take it from me, the sawdust is the real enemy out there, not the lip. Fine dust packs into the filter way faster than household stuff does and it'll fog up the little sensor windows too, which makes the thing act drunk. I blow the bin and filters out with the shop compressor every couple runs during shop season. Also, back before anyone sold fancy ramps, we just glued a strip of old carpet runner over transitions like yours. Cheap and it still works.

Total aside but this thread is making me feel better about trying this myself. My setup is a bit different because my 'garage' is really a carport with a storage room off the side, so no heated house right next door to retreat to. I'm wondering about the mapping side of things. When I carry mine out there for a one-off run like the dock advice above suggests, does it try to build a whole new map and get confused, or do the newer ones handle a second floor zone okay? Mine sometimes acts lost even in a new bedroom, so a big empty slab might send it over the edge.

Update: ran it out there a few more times and the little clack at the lip turned out to be a non-issue, just how it comes down that drop. The reply about the door seal saved me though, mine catches the weatherstrip too and it spun in place once before I trimmed the clearance back. Also pulling the filter and tapping out the sawdust after every garage run now.