We are working on two custom boards based on DA14681. One has external charging ic "MP26029" and other is using DA14681's internal charging setup.
The problem which we are facing is that when customer dont use the device for a long time, battery's voltage drop too much. sometime it goes to 0.8V or 0.6V.
Then when we plug in the charger, DA14681's charger is not able to charge the battery, even after 24 hours of plug in the charger, but other board that has external charging IC, that charges the battery within 4 5 hours.