I have just ordered smoke detectors for my garage. I have sprinklers in my garage and here is my thinking: We have a lot of power going to our cars, and several members have shown that improper wiring and bad connections have caused some melted connectors with the potential for starting a fire. Smoke detectors in garages is not code AFAIK in the US. I ordered a unit from Amazon $14.29 with a 10 year lithium battery included. I want to know about an impending fire long before it gets hot enough to set off the fire sprinklers, and I am charging when I am most vulnerable, while sleeping! This is really cheap insurance IMO and would recommend that everyone do the same. Comments?