About this replacement
Hytera HP605 / HP685 — 7.7V Li-ion Replacement Battery (BP3002)
The BP3002 is a 7.7V, 3600mAh Li-ion battery pack for the Hytera HP605 and HP685 portable two-way radios. It slots directly into the radio's battery bay and connects via the standard Hytera multi-pin contact strip. Capacity figure is 3600mAh as listed in the product specification — use that, not third-party estimates.
- HP605 and HP685 platform fit: Both models share the same battery bay dimensions, contact pinout, and BMS handshake protocol. The BP3002 pack communicates pack identity and cell state to the radio's power management circuit, which gates TX output accordingly. Either radio will accept this pack without firmware changes.
- Bench tested on actual hardware: We cycled this pack through simulated PTT bursts on the HP685 chassis. The BMS held the voltage rail steady through repeated transmit spikes and engaged overcurrent protection cleanly when we pushed above the rated draw threshold. No false cutoffs during normal keying patterns.
- First insertion into the HP605 charger dock: If the dock LED flashes fault on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat it firmly. The Hytera charger dock requires a clean contact cycle to complete the BMS handshake before it will begin charging the new pack.
Why the HP605 cuts out mid-transmission on a new BP3002
A new cell ships at storage voltage — typically around 3.7–3.8V per cell, not a full charge. When the radio keys up, transmit current draw spikes hard. If the pack hasn't been charged first, the BMS reads that voltage sag as an undervoltage event and trips the cutoff. This looks identical to a faulty battery but isn't. Charge the BP3002 fully in the dock before first use in the field and the cutoff behaviour stops.
HP685 bar indicator showing one fewer bar than expected on a new pack
The HP685 uses voltage-threshold bar indicators — it reads pack voltage at rest and maps it to a bar count. A new pack at storage voltage sits below the top threshold, so the radio displays one fewer bar even though the pack is not depleted. This is not a capacity defect. Run a full charge cycle until the dock shows green, then reinsert — the indicator will reflect the correct voltage level at 7.7V full charge.