About this replacement
Motorola MagOne Z148 / SMP418 / V418D / V468 — 7.4V Li-ion Replacement Battery (FNB-Z162)
The FNB-Z162 is a 7.4V, 1600mAh Li-ion battery for the Motorola MagOne Z148, SMP418, MagOne V468, and MagOne V418D two-way radios. It matches the OEM voltage rail and connector footprint for each model in this series. Capacity is sourced from the product data — 1600mAh / 11.84Wh.
- MagOne Z148 / SMP418 / V418D / V468 platform fit: These four models share the same battery bay dimensions, 7.4V nominal voltage rail, and side-contact connector layout. The BMS handshake protocol is consistent across the group, so one cell pack covers all four without adapter or modification.
- Bench tested on actual hardware: We cycled this pack through the MagOne dock and monitored BMS behaviour under simulated PTT load bursts. The protection circuit held cutoff at the expected over-current threshold and recovered cleanly on each cycle without latching fault state.
- First-insertion contact check: If the dock shows a fault LED on initial insertion, remove the battery and wipe the gold contact strip with a dry cloth before reseating. The MagOne platform requires a clean contact cycle to accept the new BMS handshake before charging will begin.
Why the MagOne Z148 cuts out mid-transmission on a fresh battery
A new Li-ion cell ships at storage voltage — typically 3.6–3.7V per cell, not full charge. When PTT is pressed, transmit current spikes sharply. If the pack hasn't completed its first full charge cycle, the BMS may read that spike as an under-voltage event and cut output. This is not a faulty battery. Run one full charge through the dock before the first shift and the BMS calibrates to the working voltage range correctly.
Bar indicator showing one fewer bar than expected after swap
The MagOne series uses voltage-threshold bar indicators, not a fuel gauge chip. Each bar corresponds to a fixed voltage window. A new pack at storage voltage sits below the top threshold, so the radio displays one bar fewer than a fully charged pack would show. This is not a capacity defect — it corrects after the first complete charge. Confirm the pack has reached full charge by checking that the dock LED goes solid green before removing it.