If it has a nickel cadmium battery (NI-CAD) they tend to develop a memory when charged at a certain rate.For example: If you did not charge it fully ( at least 8-10 hours or whatever instructions noted) it can only go back to that level that you charged it at . On a scale from 1-10 , let's say the charge made it to 6 ,then you used it maybe until it died and then you put it back on the charger,it will then only go back to 6 or less because the undercharging cut half of the battery's life ,therefore causing it to die out quicker. It is possible your charger is also not performing.Look at the voltage output on shaver and check the output with a volt meter and see if it reaches the manufacturers rated output.If it does reach it then you have a bad battery and I don't know if you can replace that type of battery.I hope that this helped and good luck !
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If it has a nickel cadmium battery (NI-CAD) they tend to develop a memory when charged at a certain rate.For example: If you did not charge it fully ( at least 8-10 hours or whatever instructions noted) it can only go back to that level that you charged it at . On a scale from 1-10 , let's say the charge made it to 6 ,then you used it maybe until it died and then you put it back on the charger,it will then only go back to 6 or less because the undercharging cut half of the battery's life ,therefore causing it to die out quicker. It is possible your charger is also not performing.Look at the voltage output on shaver and check the output with a volt meter and see if it reaches the manufacturers rated output.If it does reach it then you have a bad battery and I don't know if you can replace that type of battery.I hope that this helped and good luck !