You keep power on, smoke detectors that aren't battery operated will need to be active.The cost for power in the unit will be minimal you can unplug fridge, leave door propped open.Call your utility company, you should be registered as landlord for the property and in between tenants the power is reverted back to owner.You may be able to download the forms from your power company and or fill in online, or fax, each time a tenant moves in and when they move out.  

But I won't ever allow somebody with a battery or physical criminal record for the safety of tenants and neighbors.Interview Applicant:  Ideally you meet them in person and can answer any questions. 

I even placed a smoke detector in the kitchen but they just took the battery out.

There are few areas where you can invest now are Williamsburg, Brooklyn, Junonia Beach Resort, Battery Park City, Manhattan, Downtown Brooklyn etc. 

Rather the NYC market has been driven more sub-factors like the redevelopment of Battery park and Brooklyn Bridge Park, changes to zoning in Harlem, emergence of C and D areas into prime RE, the tech sector transforming certain parts of the city, etc.

Battery life of course.

I went so long without turning on my car the battery died.

I would have no cash in the game, but do all acquisition, reconditioning, managing etc... 

He rents out part of the land for pastures to place cows etc. and then some parts lets them use for tree farms and also seasonal events.The front part he reconditioned an old farm house and has a bed and breakfast with an organic garden for the corporate type wanting to get away from the big cities and take a vacation. he is retired so he doesn't mind just making a little profit and covering the taxes on the land.

Water may be leaching out under the basement floor (might be associated with cracks)There are a bunch of little things that are easy to fix (doorbells not working, loose window seals, smoke detector batteries, ect).