Inspect for structural defects and deposits.
Clean off corrosion deposits and apply silicone grease to terminals.
Push test button and observe light operation.  (See manufacturer’s instructions.)
Check vent holes.
Clean exterior with dry cloth.
Replace batteries
Unplug unit to check operation.
Clean surrounding area, record results and findings and report any needed repairs or operational adjustments.

Obtain and review manufacturer's instructions.  Follow manufacturer’s instructions or procedures if different to these instructions or procedures.
Use rubber gloves, apron and plastic face shield. 
Do not spark battery terminals or smoke while performing maintenance.

Standard and Phillips head screw drivers-various sizes; Pliers-vise grip (2), slipjoint, needlenose, diagonal; cutting pliers, side cutters; Ball peen hammer; Hack saw and spare blades; 3/8' drive socket set and ratchet; Small set of Allen wrenches; Assorted center punches, drift punches, and steel chisel; 12' measuring tape; Crescent wrenches 4" to 8";  Open and box end wrenches ¼" to ¾"; File; Pipe wrenches to 14"; Small level and square; Pocket knife; Flashlights; Grease guns and oilers; Wire brush; Extension cord and inspection lights; Various cleaning tools - brushes, scrapers, etc; Emery cloth.
Insulated pliers and screwdrivers; Wire strippers; Wire crimpers; Voltmeter - Ohmmeter – Milliammeter; Clamp on meter(volt - ohm - amp meter); Soldering kit; 1/8" 25' fish tape; Burnishing tool.
Cleaning equipment and materials
Direct Current Volt Meter
Hydrometer
Silicone grease
Face Shield
Gloves.
Acid resistant rubber apron