About this replacement
Crestron SmarTouch 1550 / ST-1700 Series — 4.8V Ni-MH Replacement Battery (ST-BTPN)
This is a 4.8V, 4000mAh Ni-MH replacement battery for the Crestron SmarTouch 1550, SmarTouch 1700, ST-1550, and ST-1700 touchscreen remote controls. These remotes are used in professional AV systems to manage lighting, audio, video, and environment controls. It replaces OEM part number ST-BTPN directly.
- SmarTouch 1550 and 1700 compatibility: Both the ST-1550 and ST-1700 use the same 4.8V cell pack with identical connector and BMS handshake requirements. A single battery revision covers the full range without modification.
- Bench tested on actual hardware: We ran this pack in a SmarTouch 1700 dock and confirmed stable voltage across the charge cycle. The BMS accepted the cell pack without fault flags or charging interruption.
- Ni-MH conditioning for touchscreen remotes: Ni-MH cells in docked touchscreen remotes can develop a voltage plateau that causes the dock to report full charge prematurely. Fully discharge the remote by leaving it unplugged until it shuts off, then charge it uninterrupted to reset the charge baseline.
Why the SmarTouch 1550 shows full charge but loses power quickly
Ni-MH cells develop memory effect when repeatedly topped off from a partial charge state. The dock reads a surface voltage and terminates charging early, leaving actual capacity well below 4000mAh. This is common in AV installs where the remote sits docked most of the time and only gets light daily use. Run one full discharge-to-shutoff cycle, then charge uninterrupted overnight to restore accurate capacity tracking.
SmarTouch remote works only at close range after battery swap
The IR LED in the SmarTouch 1550 needs a stable voltage above roughly 4.2V to drive full transmission power. A battery sitting near end-of-charge or with degraded cells drops below that threshold under IR burst load, reducing effective range significantly. If the remote only responds within a metre of the receiver, the battery is the first thing to check — not the IR sensor. Swap in a fully charged pack and retest at normal operating distance.