Mobile Rv tech-warranty work-do you guys tip????

I'm a residential HVAC service tech, we very rarely get offered tips, and normally I tell people that good feedback is a big deal to me. I would say in mainstream American culture "professional skilled techs" aren't expecting a tip, and unlike waitstaff, our compensation doesn't assume that there will be tips to boost our wage up to a livable level. That being said, an offer of a cold drink is always appreciated on a hot day.....:)