I bought a new battery for my Fairphone 4 in early November 2025 and it arrived late December. Several attempt to charge-it-to-full and discharges -until-it-turns-off fail to provide a calibrated battery that last more than 4 hrs on standby with battery saver on. However, I need a good battery for travelling with a Beeline Moto2 bluetooth navigation device that can run a bluetooth signal for many hours. This battery will not.
The original battery still lasts more than 24hrs. Several tickets to Fairphone sales support and no replies. Have there been a batch of bad batteries? If so, assuming Fairphone continue to ignore my tickets, should I buy a Cameron Sino battery from China or are these very poor quality? Are there any other makes such as Samsung battery that can be modified to fit?