About this replacement
Midland LXT600 / X-Talker T51 Series — 3.6V Ni-MH Replacement Battery (BATT3R)
This is a 3.6V, 700mAh Ni-MH battery pack for the Midland LXT600, LXT630, X-Talker T51, X-Talker T61, and compatible X-Talker series radios. It replaces OEM part numbers BATT3R, AVP14, and PB-X6. The pack fits the same footprint as the original and seats into the radio's battery compartment the same way.
- LXT600 and X-Talker platform fit: These models share a common 3.6V three-cell Ni-MH architecture and the same physical battery bay. One pack covers the full range because the voltage rail, contact layout, and BMS handshake threshold are identical across LXT600, LXT630, T51, and T61 units.
- Bench tested on actual hardware: We cycled this pack through transmit load draws on the LXT600 platform. The BMS held stable under PTT press current spikes and recovered correctly after each discharge cycle without tripping into lockout.
- First insertion after extended shelf time: If the radio shows low or no bars immediately after inserting this pack, place it in the charger for a full charge cycle before use. Ni-MH cells ship at storage voltage — roughly 1.1V per cell — which reads as near-empty on the radio's voltage-threshold bar indicator. One full charge resolves this.
Why the LXT600 cuts out mid-transmission on a freshly inserted battery
The LXT600 draws a sharp current spike the moment PTT is pressed. A Ni-MH cell at storage voltage — around 3.3V total for a three-cell pack — can sag below the radio's cutoff threshold during that spike, causing the unit to drop audio or cut transmission entirely. This is not a faulty battery. The cell simply hasn't been charged to its operating voltage yet. Charge the pack fully before first use and the cutout stops. A fully charged three-cell Ni-MH pack rests at approximately 4.1–4.2V open circuit.
Bar indicator showing one fewer bar than expected after full charge
The LXT600 uses a simple voltage-threshold bar indicator — each bar corresponds to a voltage window, not a precise capacity reading. A new Ni-MH pack often shows one bar short for the first few cycles because the cells haven't fully formed and peak voltage sits slightly below a rested, conditioned cell. This resolves after two or three full charge-discharge cycles as cell chemistry stabilises. If the indicator still reads low after three cycles, check that the battery contacts in the radio bay are clean and making firm contact — oxidised contacts drop apparent voltage at the measurement point.