Who's responsible for tools

My company keeps telling me I need to buy equipment for my job but I don't exactly have enough disposable income to do this. They gave me some tools but many of them have broken.

It's not that I am against buying my own tools, I own all my own hand tools and now my own refrigerant gauges. I just don't think it's fair to expect me to buy all this gear when I don't make a lot of money for the area I live. I've even been asked to buy batteries for a clients thermostat with my own money.

Is this common? How do other companies handle tools and gear needed to do the job.

I'm a Residential HVAC tech with an hourly pay of 21$ (California San Francisco area)