I used it on my Sony transistor radio (only required 1 AAA battery). 1st time used after charge can last for abt 2Hrs, after that the time used to play seem getting shorter and shorter. As I buy a pack of 2, I try the other battery. The 2nd battery last for 2 Hrs on 1st time after charge up. By 3rd time, for both battery cannot even last for 1/2 hr. I gave up after using for a week.
I bought the vanson battery up till now, using for 1 weeks+ still going strong. Normally a Duracell or Energizer alkaline battery can last for abt avg of 2 weeks.