I have tried many versions already but always the same issue repeats. Charger works fine when the battery has let's say 3.76 Volts when starting charging. But if the battery is nearly empty, for example at 3V..3.2V then the charging just flashes, I checked with an USB cable current measurement tool and it seems to try every 1-2seconds to charge and current jumps quickly to 0.6A only to stop again..so it doesn't really charge. I have made my design with the Webench tool and it works when connected to normal USB port and the slow charge starts automatically without problems even with empty batts.
I tried multiple Adapters but some work even worse, and it doesn't even try to start charging but with one samsung adapter it at least makes this above mentioned activity..if I charge batteries to 3.6V with another charger then it works