SportDog SD-2525 ProHunter Transmitter Compatible Battery 7.4V 650mAh

SportDog SD-2525 ProHunter Transmitter — 7.4V Li-ion Replacement Battery (SDT00-13514)

This 7.4V, 650mAh Li-ion battery fits the SportDog SD-2525 ProHunter handheld remote transmitter. It powers the unit that sends commands to receiver collars worn by dogs during field training and hunting. Voltage and cell count match the original — the transmitter's BMS will accept this cell without modification.

• SD-2525 transmitter family compatibility: The SD-2525, ProHunter 2525, and ST101-SP share the same battery bay geometry, 7.4V two-cell configuration, and connector pinout. One SKU covers the full group because the BMS handshake protocol is identical across these transmitter revisions.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SD-2525 platform. The BMS accepted the cell without triggering a protection cutoff, and voltage held within the expected window under transmitter load.
• Field transmitter storage tip: If the transmitter sits unused between hunting seasons, discharge it to around 50% charge before storing — leaving it at full charge for months stresses Li-ion cells and accelerates capacity loss faster than regular use does.

Why the SD-2525 transmitter shows full charge but dies quickly in the field

A Li-ion cell that has been deep-discharged or left depleted for an extended period loses usable capacity even after a full recharge. The BMS reports voltage-based state of charge, which can read 100% while the actual amp-hour capacity has dropped significantly. On the SD-2525, this shows up as the transmitter lasting a fraction of a normal field session before shutting down. Replacing the cell resets the usable capacity — the BMS calibration follows the new cell's actual voltage curve within a few charge cycles.

Transmitter powers on but collar stops responding mid-session

This symptom often points to voltage sag under the RF transmission load rather than a full power failure. When the cell ages, internal resistance rises — each transmit pulse causes a momentary voltage dip that can trip the BMS undervoltage protection, resetting the transmitter's RF output. The collar then loses the command signal. Fitting a fresh cell with lower internal resistance eliminates the sag; verify the transmitter holds above 7.0V under active use to confirm the new cell is performing correctly.