A Sonic Blade is an electric knife used for slicing, dicing, mincing and other cutting methods for cooking. The battery that comes with the blade is a rechargeable NIMH battery that is supposed to work for life without problems. However, in situations where the battery will not hold a charge or is not working, replacing the battery is the only way to get the Sonic Blade to work.
Call the company customer service number. The number is 1-800-970-1869. Talk to a representative and inform them about the problems. The blade advertises a battery that should last for life, so when the battery does not work it is a sign that either something is wrong with the battery or something is wrong with the charger.
Request a replacement battery. The company should send a new battery. Usually, the company will ask that you send back the old battery.
Check the new battery. If the new battery does not work as well, the problem might be the charger or you may have the wrong battery.
Look at the battery shape and type. Take the battery to the store and see if the local stores have any batteries that match the design, size and shape of the battery.
Look at online stores. Online stores will sometimes have batteries that physical stores do not have. Look for a battery that matches the appearance, dimensions and shape of the battery. Online purchases will often have information about the battery and the typical uses available in the information section.