[Sunnybob]

I apologize for not explaining myself well. I'm italian and my English is bad. I'll try to explain the situation again:
Car mounted clock. I connect the battery. The clock starts. I hear the sound of the charging and then the ticking of the mechanical part working. Every so often I hear the charging click and it goes... If I disconnect the battery it runs until it has residual charge. And it works even if I disconnect and reconnect the battery. It goes as long as he has the charge and then stops. Sometimes however, when I reconnect the battery I don't hear the sound of charging and I realize that it is stopped. The problem is after a certain amount of time (indefinable because it varies) it no longer works. If I remove it from the car I notice that it still has a residual charge because if I swing it it starts again for a certain amount of time (variable depending on the remaining charge).

Clock on the bench. It runs smoothly for hours and hours. It ran for 24 hours without any problems.