About this replacement
Dogtra 1900S / 1902S Receiver — 7.4V Li-Polymer Replacement Battery (BP74RS)
This is a 7.4V, 300mAh Li-Polymer battery for the Dogtra 1900S and 1902S Receiver units, including the 1900S-BE Black Edition and 1900S-HF Hands Free. It slots into the receiver collar — the unit worn by the dog — not the handheld transmitter. Replaces OEM part numbers BP74RS and BP74RS3P.
- 1900S / 1902S receiver compatibility: These models share the same compact receiver housing, connector pinout, and BMS communication protocol. The same 7.4V Li-Polymer cell fits all variants in this receiver family without modification.
- Bench tested on actual hardware: We cycled this battery through charge and discharge on a 1900S receiver unit. The BMS accepted the cell without fault codes, charge termination triggered correctly at full voltage, and stimulation output held consistent across the test range.
- First-use receiver pairing after battery swap: After fitting this battery, power on the receiver outdoors and keep it within range of the transmitter. A freshly powered receiver re-establishes its RF link with the transmitter within a few seconds — confirm the link indicator on the transmitter shows solid before starting a session.
Why the 1900S receiver stops responding mid-session after a battery replacement
The 1900S receiver's BMS monitors cell voltage in real time and cuts output if voltage drops below its low-cell threshold — typically around 6.4V under load. A partially discharged or poorly seated replacement cell can trigger this cutoff during active stimulation bursts, which draw a short spike of current. If the receiver goes unresponsive mid-session, the first check is the battery seating — the contacts must be flush. Charge the new battery fully before the next session to ensure the BMS starts with accurate state-of-charge data.
Receiver charge indicator stays red and never turns green
This usually means the BMS entered a protection state during a deep discharge — common when a collar sits unused for several months. The cell voltage drops below the BMS re-entry threshold, and the charger cannot initiate a normal charge cycle. Connect the receiver to its Dogtra charger for 30–60 minutes even if the LED appears stuck; some BMS chips trickle-charge at a low rate before switching to full current. If the indicator still does not transition to green after that period, check charger output — it should read approximately 8.4V DC at the connector tip.