About this replacement
Retevis RT22 / RT22S Series — 3.7V Li-ion Replacement Battery (BL22)
This is a 3.7V, 950mAh Li-ion replacement for the Retevis RT22, RT22S, DT22, and RT622 two-way radios. It uses OEM part numbers BL22 and BL19 and slots into the original battery bay. Swap it in when the stock pack no longer holds a charge through a full shift.
- RT22 series platform fit: The RT22, RT22S, DT22, and RT622 share the same 3.7V single-cell architecture and battery bay dimensions. One pack covers all four models because the connector pinout, BMS handshake voltage, and physical latch are identical across that production run.
- Bench tested on actual hardware: We cycled this pack through charge and transmit loads on the RT22. The BMS held steady through repeated PTT bursts, absorbed the transmit current spike without tripping, and returned to charge acceptance correctly after each discharge cycle.
- First insertion into the Retevis dock: If the charger LED blinks or shows a fault on first insertion, remove the pack and wipe the gold contact strip with a dry cloth before reseating. Retevis docks require a clean contact cycle to complete the BMS handshake — a smudged contact is the most common reason a new pack reads as a fault.
RT22 BMS trip on PTT press with a new pack
The RT22 draws a sharp current spike the moment PTT is pressed — transmit current is significantly higher than standby draw. On a new pack fresh from storage, the cell sits at around 3.6–3.7V. If the BMS reads that spike as an overcurrent event, it can trip and cut the radio mid-keying. This is not a faulty pack. Let the battery complete one full charge cycle before heavy use so the BMS calibrates its overcurrent threshold against a fully topped cell.
Bar indicator showing one fewer bar than expected on a new BL22
The RT22 uses a simple voltage-threshold bar indicator — each bar corresponds to a voltage band, not a percentage. A new pack ships at storage voltage, typically 3.6V, which sits at the top of the second bar rather than the third. This looks wrong but is not a defect. Charge the pack fully to 4.2V and the indicator will step up to its correct reading.