SportDog DC-23 Sporthunter SD-800 Replacement Battery 7.2V 210mAh

SportDog Sporthunter SD-800 — 7.2V Ni-MH Replacement Battery (DC-23)

This is a 7.2V, 210mAh Ni-MH battery for the SportDog Sporthunter SD-800 and Wetlandhunter SD-800 remote training collars. It restores stimulation and tone output when the original cell no longer holds a charge. Also fits the ST-120 and ST-120W transmitters listed in the compatibility range.

• SD-800 collar and ST-120 transmitter compatibility: Both the receiver collar and handheld transmitter in this system run the same 7.2V Ni-MH cell at this form factor. The DC-23 footprint — 31.55 x 20.80 x 23.00mm — matches the original battery bay without modification. OEM cross-references include 650-104, SDT00-11911, SDT00-11435, and SDT00-12647.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the SD-800 collar platform. The Ni-MH chemistry accepted a full charge without thermal event, and the collar's stimulation circuit triggered normally across all intensity levels.
• First charge after installation: Ni-MH cells in low-capacity training collar applications can arrive partially discharged from storage. Run a full charge cycle before the first field session — partial charge going into a training day means the collar may cut out before the session ends.

Why the SD-800 collar loses stimulation output before the battery indicator drops

Ni-MH cells at 210mAh have a steep voltage curve near end-of-discharge. The SD-800's stimulation circuit requires a minimum voltage rail to fire at full intensity — when the cell sags under load, tone functions may still work while stimulation output drops noticeably. This can look like a collar fault when it is actually a battery condition. If stimulation feels inconsistent, check the collar's charge level with the OEM charger indicator rather than relying on LED blink count alone.

Collar not responding to transmitter commands after battery replacement

Swapping the battery clears the collar's active session state. Some SD-800 units require a full power cycle on both the collar and the ST-120 transmitter before they re-establish their paired link. Power both units off completely, then power the transmitter on first, followed by the collar. If the collar still does not respond, hold the collar's power button for 10 seconds to force a full reboot before re-pairing.