Excellent unit. Recommend for RPi Projects
Test: Vout =5.1 V (all meas.) Vin:4V: I load =1A, I in = 1.4A (91%) Vin:4V: I load =2A, I in = 2.9A (87%) Vin:3V: I load =1A, I in = 1.86A (91%) Vin:3V: I load =2A, I in = 4.2A (81%) I did not test for 3A, but with 2A becomes already hot and efficiency drops, I suggest to used it for 1A nominal load and 2A max load for short time, not more