Sears is a leading home appliance retailer. Your 19.2 volt battery you got from Sears is likely to have the brand name Craftsman or Diehard on the label; Craftsman includes cordless powers in their range of products while Diehard is known for their selection of batteries. Your Sears 19.2 volt battery contains lithium ion cells which are the latest type of rechargeable cell and should last several years maintenance-free. Lithium ion battery packs are usually sealed units and should not be tampered with; if you break into the pack your warranty is void, and it is potentially dangerous. If you find your 19.2 volt battery won't charge, check out the battery charger, as it's quite likely to be the cause of the problem.
Plug in your charger and insert the 19.2 volt battery. The battery charger has LED lights on it which illuminate to indicate if the battery is charging, or is charged. They are usually red for charging and green for charged. If no lights illuminate there's no power getting to your battery. If a light comes on and your battery doesn't take a charge you need to get it checked out by a specialist.
Remove the 19.2 volt battery from the charger. Unplug the charger from the mains electricity socket.
Look on the plug for a fuse holder. Plugs attached to wires that connect to battery packs generally are factory-sealed for safety and the fuse is in the base of the plug. Lift off the plastic fuse holder using a small flat-head screwdriver. The fuse in attached to the inside of the holder. Remove the fuse by sliding it out of the holder.
Replace using a new fuse. Ensure the ampere rating is the same as the fuse you removed. The rating is printed on the side of the fuse. Put the fuse into the holder by sliding it in place then push the holder into the base of the plug using your fingers.
Insert the plug into the socket. Place your 19.2 volt battery into the charger. The charging light should illuminate if the fuse had blown. If the light comes on and after a while your battery still doesn't have a charge, you need to get the battery checked out professionally. If the charging light doesn't illuminate, remove the battery from the charger and remove the plug from the socket.
Check the underside of the charger to find the charger fuse. The battery charger is effectively a transformer that reduces the incoming mains power of 120 volts to the voltage required to charge your battery; in this case 19.2 volts. The fuse in the charger prevents your battery getting overcharge; if there's a problem occasionally it can blow.
Remove the fuse cover. You find a small Phillips screw holding the cover in place, or it unclips. Use a screwdriver to remove the screw, or use a screwdriver to pry open the fuse cover. Remove the fuse from the holder by pulling it out using your fingers.
Put a new fuse into the holder. Ensure you get a fuse that has the same rating as the one you removed. Replace the fuse cover; either screw it into place or push it in place using your fingers.
Put the battery 19.2 volt battery in the charger. Put the plug into the main socket. The charging light illuminates and your battery starts charging, if the fuse was the cause of the problem. If the light comes on and after a while your battery still doesn't have a charge, you need to get the battery checked out professionally. If the light still doesn't illuminate you need to get your charger checked or replaced.