Radio not working on battery

One of my Radios has suddenly decided to stop working on battery. On startup it shows the Logitech symbol then shuts down. If I hold my finger on the power button the Logitech symbol is displayed until I release the button. If powered by mains the battery appears to be charging and reports normal voltages but unplugging the mains causes it to shut down.

Sent from my SM-G900F using Tapatalk