Hi Rongzhong, I’m a primary maker and not good at electronic current layout or calculating. A few days ago, In process of calibrating that I could not make it well, when I restarted Nybble, Nybble could not work at all(with no FIDI connected to computer). I found Nybble V0-1 was wield that 14500 lithium ion batteries(at the time were about 8V,bought from local shop) could not supply any power to the V0 board, then I measured at the terminals(shown as “gnd”,”battery” on the board of V0-1, linked from battery set), it shown about 0.19V, batteries still were about 8V, the battery set and wires is normal. But I checked and connected with FIDI to the Nybble V0-1, Nybble could start again,but with handicapped servos’ actions. And It could upload any sketches well and run it. So I used “9V” battery(measured about 7.4V) instead of Li-ion batteries, It could start Nybble but still with handicapped servos’ actions, then I measured “9V” battery worked electronic current was about 2500-2600mA(not enough to drive all servos),at the same time, the 14500 lithium ion batteries shown more 8A? above(one probe of electric meter was very hot). I try alkaline batteries (about 3-4V ) still could not start Nybble. I don’t know why? In V0_1 borad electronic current layout, how many worked electronic current could drive well all servos?