If it goes dark you need to make sure location is good.NN, 8.3 cap, 3 years left primary term is a loser to me.I have seen batteries plus, banks, dollar stores, etc. take over the rare pharmacy location that goes dark.Roof is flat and if A/C etc.is old to replace roof and mechanicals is tens of thousands of dollars or more.

Should be $5-10$250 to replace smoke detector batteries ??? 

I paid $150 for my first car but a battery in it and drove it for 3 years.

Clean common area and collect my washing machine quarters.6 months I change the batteries in the smoke detectors/CO, fire extinguisher inspection/charging6 months I do a plumbing inspection6 months I do a thermostat battery changeNovember I do a radiator bleed.None are done at the same time and I do a complete walk through when doing.My buildings are across from town hall and the police station.

Take time off, recharge your batteries, center yourself.

Fire code states if a house was built prior to 1976 it can have battery operated smoke detectors.

(I apologize for the format; my copy is in columns and it did not transfer very well.)Move-Out Charge SheetCleaningClean refrigerator $25.00Clean stove top $10.00Clean oven $30.00Clean kitchen cabinets $30.00Clean kitchen floor $25.00Clean kitchen countertops $15.00Clean tub/shower surround $30.00Clean sink $15.00Clean toilet $20.00Clean bathroom cabinets & floor $20.00Window cleaning (per window) $10.00Vacuum/sweep through dwelling $40.00FlooringRepair carpet $85.00Replace linoleum $6/sq. ft.Replace floor tile $75.00 ea.Replace laminate flooring $10/sq. ft.WallsRemove/treat mildew (per surface) $15.00Repair hole in wall $55.00Repaint (per wall/ceiling) $40.00DoorsReplace door (interior) $165.00Replace door (exterior) $485.00Replace weather stripping $25.00ElectricalReplace light bulb $3.00Replace light fixture globe $20.00Replace light fixture $65.00Replace electrical outlet/switch $15.00Replace electrical cover plate $2.00PlumbingReplace kitchen faucet $150.00Replace bathroom faucet $105.00Replace faucet handle $20.00Replace faucet aerator $10.50Replace shower head $27.00Replace toilet $175.00Replace toilet seat $25.00LocksReplace key (door or mailbox) $10.00Replace cylindrical door lock $35.00Replace deadbolt lock $25.00Windows and Window CoveringsReplace window pane (single) $75.00Replace window pane (double) $125.00Replace mini blind $20.00Rescreen window screen $25.00Replace window screen and frame $50.00MiscellaneousReplace refrigerator shelf $25.00Replace stove/oven knob $20.00Replace plastic countertop $275.00Replace mirror $45.00Replace medicine cabinet $75.00Replace towel bar $25.00Replace shower curtain rod $25.00Replace shower curtain & rings $13.00Replace shower/tub enclosure $350.00Replace thermostat $80.00Replace fire extinguisher $30.00Remove junk and debris (per area) $35.00Replace smoke detector $15.00Replace combo detector/alarm $40.00Replace alarm battery (per battery) $2.00Replace drop ceiling tile $10.00Replace wireless doorbell $35.00Replace portable window screen $10.00Actual charges may vary based on condition and/or vendor bill.

A permanent solar system with battery row $ 22000 ? 

I replaced them with battery operated wireless switches.

Since that's dark, more light is preferable.I bought some LED light strips (3-4 lights each) that are battery-operated.