Midland ER300 DAB Radio Replacement Battery BATT20L 3.7V 2600mAh

Midland ER300 / ER200 — 3.7V Li-ion Replacement Battery (BATT20L)

This is a 3.7V 2600mAh Li-ion replacement for the OEM BATT20L battery. It fits the Midland ER300 and ER200 DAB digital emergency alert radios. Both models use the same battery housing, connector, and BMS communication protocol, so one part covers both.

• ER300 and ER200 compatibility: Both radios share the same 3.7V power rail, physical cell dimensions, and PCB protection circuit handshake. The ER200 and ER300 draw from an identical battery bay, so the BATT20L fits either unit without modification.
• Bench tested on actual hardware: We ran this cell through charge-discharge cycles on the ER300 platform. The BMS protection circuit responded correctly to over-charge, over-discharge, and short-circuit conditions, and the radio powered on cleanly across all test cycles.
• DAB station list after power interruption: After fitting a new battery, let the ER300 run an automatic full station scan before manual tuning. DAB radios store ensemble and service data in volatile memory — a power break from swapping cells clears that list, and the radio needs a fresh scan to rebuild it correctly.

Why the ER300 cuts out mid-station at low battery

DAB decoding is not tolerant of voltage sag. The OFDM decoder inside the ER300 requires a steady supply voltage to process the multiplexed stream — when cell voltage drops below approximately 3.2V under load, the decoder loses sync and the audio drops out entirely rather than degrading gradually. This is different from analogue FM, where a weak signal produces static. On DAB, a marginal voltage means a hard cut. If the radio stops mid-stream and restarts when you reconnect power, a depleted or degraded cell is almost always the cause.

ER300 reception noticeably worse on a new battery than expected

DAB receivers scale RF output based on available supply voltage. In weak signal areas, the ER300 pulls higher current to maintain reception — a cell that has internally aged cannot hold voltage under that elevated draw, so RF output is throttled and signal acquisition suffers. A new BATT20L at full charge eliminates the supply-side constraint. If reception is still poor after fitting a fresh cell, check the telescopic antenna is fully extended and vertical — that is the single biggest variable affecting DAB signal quality on portable units.