Complete nonsense to buy this plastic battery box. At this price you can buy a PowerBank with a very high capacity. and connect via USB. With a 20,000 mAh PowerBank, the life is much more than 17 hours. Or rechargeable AA batteries. Anyway, quality design worthy of Tascam, but in the price-performance ratio it is worthy of 1 in 10. You need to realize that you will actually be charging it with batteries that will be reflected in the costs. The device was launched on the market at a time when we only dreamed of PowerBanks of current high capacities. So it had its justification back then. Personally, I bought the DR-05 from Muziker and I feed it with 2x2400 mAh NiMh that can withstand non-STOP recording with the display lit for more than 12 hours. I have 4 sets of two batteries, so NO problem. I considered buying it but the price clearly discouraged me.