About this replacement
Motorola GP900 / HT1000 Series — 7.4V Li-ion Replacement Battery (NTN7143)
This 7.4V, 1800mAh Li-ion cell replaces the NTN7143 battery pack used in the Motorola GP900, GP1200, HT1000, HT6000, and over a dozen related professional handheld radios. It fits the same battery bay and connector as the original Motorola pack. Voltage and capacity match OEM spec directly — no adapter needed.
- GP900 / HT1000 platform compatibility: These models share the same 7.4V rail, battery bay geometry, and BMS handshake protocol. One pack covers the full series because Motorola standardised the connector and charge termination signal across this generation of land mobile radios.
- Bench tested on actual hardware: We ran this pack through a full charge cycle on a Motorola rapid charger dock. The BMS accepted the charge handshake without fault, cell balancing completed normally, and the dock advanced to green without intervention.
- First insertion on the dock: If the charger shows a fault LED on first insertion, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The Motorola platform requires a clean contact cycle to accept the new BMS handshake before charging begins.
Why the GP900 cuts out mid-transmission on a freshly inserted pack
Pressing PTT on the GP900 draws a sharp current spike — transmit current can jump to 2A or more in under 100ms. If the battery BMS detects this as an overcurrent event, it trips the protection circuit and cuts output voltage instantly. This looks like a dead radio or a dropped call, but the pack itself is fine. The fix is to let the pack complete one full charge cycle before heavy PTT use — a partially charged cell has higher internal impedance, which amplifies the voltage sag that triggers the BMS. After a full charge to 8.4V, the overcurrent threshold clears and transmit behaviour returns to normal.
Bar indicator showing one fewer bar than expected after swap
New Li-ion cells ship at storage voltage — typically around 3.7–3.8V per cell, or roughly 7.4–7.6V for a 2S pack. The GP900's voltage-threshold bar indicator reads that as one bar below full, which is accurate for storage charge. This is not a faulty pack. Put the battery on the charger dock and run it to full charge termination — the dock LED will go green when the pack reaches approximately 8.4V. After that first full charge, the bar indicator will read correctly.