About this replacement
Motorola EVOLVE LTE — 3.85V Li-ion Replacement Battery (BT000593A01)
This 3.85V, 5800mAh Li-ion battery replaces the OEM pack in the Motorola EVOLVE LTE portable two-way radio. It also fits the AR494948 and HK2157A variants. Voltage, connector, and BMS communication match the original Motorola specification.
- EVOLVE LTE, AR494948, and HK2157A compatibility: All three share the same battery bay geometry, contact pin layout, and 3.85V BMS handshake protocol. One pack covers the full variant group without modification.
- Bench tested on actual hardware: We ran this pack through a full charge-discharge cycle on the EVOLVE LTE platform. The BMS accepted the dock handshake on first insertion and held voltage within spec across the complete cycle. No overcurrent trips were recorded during simulated PTT transmit loads.
- First insertion contact check: If the charger dock shows a fault LED on the first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The EVOLVE LTE platform requires a clean contact cycle before the dock accepts the new BMS handshake and begins charging.
Why the EVOLVE LTE cuts out mid-transmission on a new battery
New Li-ion cells ship at storage voltage — typically around 3.6–3.7V — not at full charge. When the radio transmits, the RF amplifier draws a surge of current. If the cell hasn't been fully charged first, that surge pulls the terminal voltage below the BMS cutoff threshold and the radio drops the transmission. This is not a faulty pack. Charge the battery fully before first field use and the cutout will not recur.
Bar indicator showing one fewer bar than expected on a new BT000593A01
The EVOLVE LTE uses simple voltage-threshold steps to drive the bar indicator — each bar corresponds to a voltage band, not a percentage. A new pack at storage voltage sits in a lower band, so the display shows one or two bars even though the cell is not depleted. After a full charge cycle brings the pack to 4.2V, the indicator will read the correct level. No calibration procedure is needed — the display updates automatically as cell voltage rises.