How to Replace a Basement Watchdog Backup Battery

Sump pumps are meant to remove water from a sump pit, commonly found in a house's basement, so as to keep the basement floor dry.

A sump pump with a backup battery continues to function even if the home's electric power supply fails. You can replace a Basement Watchdog-brand battery if the one inside the sump pump no longer holds a charge. The proper battery is available directly from the company or from select hardware stores or pool/spa supply centers. Read the owner's manual to determine the battery strength needed for your model.

Put on protective clothing, goggles and gloves. Place the battery box that is included with the Basement Watchdog-brand battery on a work surface with the open end facing up.

Place the battery, contact caps facing up, into the battery box. Insert the tip of a flat-edge screwdriver beneath a side of one of the two battery contact caps. Lift up on the tip to raise the cap. Pull the cap off. Repeat this with the other cap. Dispose of the caps.

Place the box that that is perforated at the top (included with the Basement Watchdog-brand battery) and which contains the acid that activates the battery on the work surface. Push the perforated tab on the top of the box in with the tip of the flat-edged screwdriver. Pull the tab out from the box using the screwdriver's tip.

Grip the top of the hose that is inside the hole now exposed. Extend the hose out from the box. Squeeze the top of the hose to drive any acid inside back into the box.

Snip the top of the hose with scissors. Upend the hose into the holes on the battery, beneath the battery contact caps. Fill each hole with acid from the hose until the level indicator cap ring hole next to the battery contact cap is filled three-quarters of the way.

Place the acid box back on the work surface once the acid has been added to the battery. Push the hose back into the box. Dispose of the box properly.

Unplug the sump pump's power cord from the wall outlet providing it with power. Remove the screws from the side panel using a Phillips screwdriver.

Loosen the two contact screws on the top of the battery inside the pump. Pull the lugs off each screw; make a note of which color wire is attached to each lug. Pull the battery out of the pump. Pull the sensor wire out of the yellow cap that is on the top of the battery.

Pull the yellow cap off the battery. Dispose of the battery properly.

Rinse the yellow cap in tap water and dry it with a soft cloth. Place the yellow cap on the top of the Basement Watchdog-brand battery so that it is in the same position as it occupied on the other battery. Push the two battery contact caps back on.

Loosen the two contact screws on the top of the Basement Watchdog-brand battery. Attach a lug from each of the two wires in the pump to the screws in the same manner as they occupied on the other battery. Tighten the screws.

Locate the horizontal sensor rod that is inside the pump. Grip the rod. Place the end of the rod into the hole in the yellow cap. Place the Basement Watchdog-brand battery into the pump's compartment. Close the panel and reattach the screws. Plug the power cord back into the wall outlet.

Things You Will Need

  • Protective clothing
  • Goggles
  • Gloves
  • Flat-edged screwdriver
  • Scissors
  • Phillips screwdriver


  • Keep children and pets away while you are preparing the replacement battery for use.


  • Never touch either of the exposed contacts on a backup battery, as there is the potential for being shocked.

About the Author

Marshal M. Rosenthal is a technology maven with more than 15 years of editorial experience. A graduate of Brooks Institute of Photography with a Bachelor of Arts in photographic arts, his editorial work has appeared both domestically as well as internationally in publications such as "Home Theater," "Electronic House," "eGear," "Computer and Video Games" and "Digitrends."