The average charge of a good massager does not exceed 3 hours of use, which is a good average as under no circumstances should you spend all that time using the massager on your body. There are devices that use conventional alkaline batteries, but these tend to last less than two hours.
It is always recommended to invest in equipment whose batteries can be recharged using a charger. Good, quality massagers can last a lifetime, others have a lifespan of between 5 and 10 years. It all depends on the brand and the care you take of it.