SportDog YardTrainer SD-350 Replacement Battery 7.2V 130mAh

SportDog YardTrainer SD-350 / FieldTrainer SD-400 Series — 7.2V Ni-MH Replacement Battery (SAC00-15724)

This is a 7.2V, 130mAh Ni-MH replacement battery for the SportDog YardTrainer SD-350, FieldTrainer SD-400, FieldTrainer SD-400S, and WetlandHunter SD-400 CAMO training collars. It matches the OEM part number SAC00-15724 and fits directly into the collar's battery housing. Replace it when the collar stops holding a charge or fails to respond to the remote transmitter.

• SD-350 / SD-400 series compatibility: These four models share the same battery cavity dimensions (31.10 × 22.60 × 15.90 mm), the same 7.2V Ni-MH chemistry, and the same connector orientation — so a single part number covers all of them without modification.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on a SD-400 collar. The BMS accepted the charge without fault codes, and stimulation output remained consistent across the full discharge curve down to the low-voltage cutoff.
• First charge after installation: SportDog collar chargers use a trickle-charge profile tuned for Ni-MH cells. Let the collar charge to 100% before the first training session — the BMS needs a full initial cycle to calibrate the state-of-charge reading correctly.

Why the SD-350 collar stops responding mid-session even with a charged battery

At 130mAh, this is a small cell with limited instantaneous current headroom. When stimulation is triggered repeatedly in rapid succession, voltage can dip momentarily below the BMS cutoff threshold even if the battery is not depleted. This is more common with aged cells where internal resistance has climbed. A new cell with lower internal resistance recovers faster between pulses, keeping voltage above the cutoff during back-to-back commands. If the collar was cutting out with the old battery, a fresh cell at full charge should clear it.

Collar shows "charged" but stimulation output is weak or inconsistent

Ni-MH cells that have been repeatedly shallow-cycled develop a voltage depression sometimes called the memory effect — the cell reports a surface charge rather than true capacity. The collar's charge indicator reads voltage, not actual stored energy, so it can show full while the usable capacity is significantly reduced. Run the collar down fully until it no longer responds, then charge to 100% without interruption. If the problem persists after two full cycles, the cell has degraded and needs replacement — this battery resolves that.