Kolida BTKD-L7402W GPS GNSS K9 Replacement Battery 7.4V

Kolida GPS GNSS K9 Series — 7.4V Li-ion Replacement Battery (BTKD-L7402W)

This 7.4V, 2200mAh Li-ion battery replaces the BTKD-L7402W pack in the Kolida GPS GNSS K9, K9E, K9T, and K9TX surveying receivers. It fits the same battery bay and connector as the original, with no modification needed. Capacity is 2200mAh (16.28Wh) — matched to the product data, not estimated from field reports.

• K9 series compatibility: The K9, K9E, K9T, and K9TX share the same battery housing, voltage rail, and BMS handshake protocol. One pack covers the full platform — the receiver's firmware reads cell state the same way across all four variants.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on the K9 platform. The BMS communicated charge state cleanly and held voltage within expected tolerance under the receiver's GPS and GLONASS simultaneous tracking load.
• Pre-deployment calibration cycle: After installing this pack, run a full system calibration through the K9 receiver's instrument menu before heading into the field. The receiver maps battery state during calibration — skipping this step causes premature low-battery warnings during your first measurement session, even with a fully charged pack.

BMS cutoff when the K9 initialises its GNSS tracking modules

When the K9 powers on, it initialises GPS and GLONASS tracking simultaneously. That module startup draws a short current spike — higher than the receiver's steady tracking load. A new or cold pack with a marginal BMS can interpret this spike as a fault and cut power before the receiver finishes booting. This is a BMS threshold event, not a faulty receiver. Charging the pack to full before the first power-on reduces the chance of this trip occurring.

Pack will not charge after the receiver sat unused for months

Li-ion cells left in storage self-discharge over time. If the K9's battery drops below approximately 2.5V per cell, the BMS enters a protective sleep state and blocks normal charging. The charger shows no activity or immediately stops. To recover the pack, use a charger that supports a low-current pre-charge mode — sometimes called trickle or recovery mode — to bring the cell voltage back above 3.0V before switching to standard charge rate. If the pack does not respond after 30 minutes of recovery charge, the cells have passed the point of safe recovery and the pack needs replacement.