Unfortunately, after reading the good reviews, I bought 2 cables (1 of 1m and 1 of 2m). The cables are terrible. They don't charge at all from 2 different (both in power and brand) portable batteries. They start charging and then stop after a few seconds. Both cables are the same! In a regular charger, one works and one doesn't! It's a hit or miss. If it manages to connect and start charging, it's okay, it doesn't disconnect! It's a complete disappointment, especially if it's for powering from external batteries!