SportDog SDT00-15944 Compatible Battery 3.7V 390mAh Li-Polymer

SportDog SportHunter 1225 / SD-1225 — 3.7V Li-Polymer Replacement Battery (SDT00-15944)

This 3.7V, 390mAh lithium-polymer battery replaces the OEM pack in the SportDog SportHunter 1225 and SD-1225 e-collars, along with the SportHunter 1825 and SD-1825 variants. It powers the collar's receiver unit, which handles both training stimulus delivery and remote signal reception from the handheld transmitter. Dimensions are 40.40 × 25.62 × 4.72mm — measure your existing cell before installing if you are unsure of your exact model.

• SportHunter 1225 / 1825 receiver compatibility: These collars share the same receiver housing form factor and voltage rail, which is why both model series use the same 3.7V Li-Polymer cell. The BMS inside the receiver accepts charge via the OEM dock connector and monitors cell voltage during discharge to protect the correction circuitry from undervoltage drops.
• Bench tested on actual hardware: We cycled this cell through the OEM charging dock and confirmed the BMS accepted charge without fault flags. Discharge testing verified the cell holds voltage through repeated stimulus pulses without triggering the receiver's low-voltage cutoff prematurely.
• First GPS acquisition after install: After fitting this battery and powering the collar on, take the dog outside immediately. GPS trackers perform a cold start after any power interruption — allow 5 to 10 minutes outdoors for the first location fix. Subsequent warm-start updates are significantly faster.

Collar battery draining faster in rural and low-signal areas

In areas with weak cellular or GPS signal, the SportHunter collar's radio and GPS modules increase transmit power and polling frequency to maintain a fix and stay connected to the network. This draws measurably more current from the 390mAh cell than operation in open-sky, strong-signal conditions. A fresh cell draining faster than expected in the field is often a signal-environment issue, not a battery defect. If drain is severe, check whether the collar is set to continuous tracking mode rather than periodic reporting — switching modes reduces draw significantly.

Collar not syncing to the SportDog app after a battery swap

After a full power interruption — which a battery swap causes — the collar's Bluetooth and cellular modules lose their active session with the app. The device does not automatically re-register; it needs to be rediscovered. Open the SportDog app, remove the collar from your paired devices list, then re-add it from scratch. If the app still does not detect the collar, confirm the collar LED is solid rather than flashing, which indicates it has completed boot and is broadcasting.