About this replacement
Motorola XTS1500 / XTS2500 Series — 7.4V Li-ion Replacement Battery (NTN9815)
This 7.4V 3350mAh Li-ion battery replaces OEM part NTN9815 and its variants in Motorola XTS1500, XTS2500, PR1500, and MT1500 portable land mobile radios. These are professional-grade two-way radios used across public safety, emergency response, and enterprise communications. The pack delivers 24.79Wh of capacity in the same form factor as the original Motorola battery.
- XTS/MT/PR platform fit: The XTS1500, XTS2500, PR1500, and MT1500 share the same battery bay dimensions, contact pin layout, and 7.4V nominal voltage rail. That is why a single pack covers this group — the BMS handshake protocol and connector are identical across the platform.
- Bench tested on actual hardware: We cycled this pack through full charge and transmit-load discharge on an XTS1500 body. The BMS held cutoff at the correct low-voltage threshold and did not trip on PTT press — including repeated back-to-back transmissions at full RF output.
- First insertion into the charger dock: If the dock shows a fault LED on first insertion, remove the battery, wipe the gold contact strip with a dry cloth, and reseat firmly. The Motorola XTS platform requires a clean contact cycle to accept the new BMS handshake before charging begins.
Why the XTS1500 cuts out mid-transmission on a new battery
New Li-ion cells ship at storage voltage — typically 3.6–3.75V per cell, not the 4.2V full-charge ceiling. Under a PTT transmit spike, the XTS1500 draws a sharp current burst for RF output. If the pack has not been fully charged first, that spike can pull cell voltage below the BMS overcurrent threshold momentarily, triggering a cutoff that kills the transmission. The radio then resets and returns to standby as if nothing happened. A full charge cycle before first use resolves this — the cells need to reach full voltage before sustaining transmit-load current without sag.
Bar indicator showing one fewer bar than expected after install
The XTS series uses simple voltage-threshold bar indicators — each bar corresponds to a voltage band, not a fuel gauge IC reading. A new pack at storage voltage will read one or two bars low immediately after insertion. This is not a capacity defect. Place the battery in the charger and let it complete a full charge cycle. Once cell voltage reaches approximately 8.4V (4.2V per cell), the indicator will display the correct number of bars.