About this replacement
Motorola XTS1500 / XTS2500 / MT1500 — 7.4V Li-ion Replacement Battery (NTN9815)
This 7.4V, 2800mAh Li-ion battery replaces the original pack on Motorola XTS1500, XTS2500, PR1500, and MT1500 portable radios. It matches the OEM voltage rail and connector footprint these platforms share. Use the product data capacity figure — 2800mAh — as the reference for this listing.
- XTS/MT platform compatibility: The XTS1500, XTS2500, PR1500, and MT1500 share a common battery bay, contact arrangement, and BMS handshake protocol. Swapping between these models requires no modification — the same connector and voltage rail runs across the entire platform.
- Bench tested on actual hardware: We ran this pack through charge and transmit cycles on XTS-series hardware. The BMS held stable under sustained PTT draw and completed the dock handshake without triggering a fault LED on the first insertion.
- Contact strip on first dock insertion: If the charger shows a fault LED when you seat this pack for the first time, pull the battery and wipe the gold contact strip with a dry cloth before reseating. The XTS charger dock requires a clean contact cycle to complete the BMS handshake before it begins charging.
Why the XTS1500 cuts out mid-transmission on a new battery
New Li-ion cells ship at storage voltage — typically around 3.6–3.7V per cell — not at full charge. When you press PTT, the transmitter draws a current spike that can push the BMS into an overcurrent trip if the cell voltage is already sitting at the low end of the storage range. The radio cuts out not because the battery is faulty, but because the BMS is protecting the cells from a high-current pull at low state of charge. Fully charge the pack before the first operational use to bring both cells above the BMS trip threshold.
Bar indicator showing one fewer bar than expected after fitting this pack
The XTS series uses voltage-threshold bar indicators — each bar corresponds to a voltage band, not a percentage readout. A new pack at storage voltage sits in a lower threshold band, so the radio displays one or two bars even though the cell capacity is intact. This is not a capacity fault. Charge the battery fully in the dock until the charger LED goes green, then reinsert — the indicator should read at the top threshold band above 8.2V.