Thanks for feedback. My batteries are two years old. If I listen over a weekend, they discharge over the next day or two. If I want to listen to music say a week later, I need to turn on the charger and charge for 15 minutes before turning the pre-amp unit on. After the batteries have been completely charged up the unit runs less than 2 minutes from battery. My sense is that Nagra is not buying batteries from the best supplier.
