About this replacement
Pure Avalon N5 / Evoke D4 Series — 3.7V Li-ion Replacement Battery (F1)
This is a 3.7V 10400mAh Li-ion battery that replaces part number F1 in Pure DAB digital radios. It fits the Avalon N5, Evoke D4, Evoke D4 Domino, Evoke D4 Mio, and eleven additional models in the same family. Swap it when the original battery no longer holds charge or the radio powers off unexpectedly.
- Avalon N5 and Evoke D4 family fit: These models share the same battery bay dimensions, F1 part number, and 3.7V supply rail. The connector and BMS handshake are identical across the range, so one battery covers the full group.
- Bench tested on actual hardware: We ran this battery through charge and discharge cycles on a Pure Evoke D4. The BMS held the output voltage steady across the load range the DAB decoder draws and cut off cleanly at the low-voltage threshold without triggering false shutdowns.
- Post-install scan tip: After fitting this battery, run a full auto-scan from the radio's menu before attempting manual tuning. DAB station lists are held in volatile memory and are wiped when power is fully interrupted — a fresh auto-scan rebuilds the complete station index for your region.
Radio cutting out mid-station at low battery
The DAB decoder in the Avalon N5 and Evoke D4 requires a stable voltage to process the OFDM stream continuously. When battery voltage sags below roughly 3.2V under load, the decoder loses sync and the radio cuts audio or reboots. This happens faster on multiplexes with high bit-rate stations because the tuner draws more current. A battery with degraded cells hits that sag point earlier in the discharge curve than a fresh one does.
Saved stations gone after fitting a new battery
Pure DAB radios store the station list in volatile RAM that loses its contents the moment main power is removed. Fitting a replacement battery is a full power interruption, so the list clears every time. This is not a fault with the new battery or the radio. Go to Menu → Settings → Auto-tune and let the radio complete a full scan — it will repopulate every receivable station and restore your presets.