CalAmp LMU-1100 GPS Compatible Battery 3.7V 900mAh

CalAmp LMU-1100 / LMU-1200 Series — 3.7V Li-Polymer Replacement Battery (1BF112-453443CON)

This 3.7V, 900mAh Li-Polymer cell replaces the original internal battery in CalAmp LMU-1100, LMU-1200, LMU-2600, and LMU-2700 GPS tracking units. These are compact fleet and asset trackers that run continuous GPS positioning alongside cellular data transmission — a combination that puts steady current demand on a small cell. At 50.00 x 30.00 x 5.80mm, this cell matches the original footprint for a direct fit inside the housing.

• LMU-1100 / 1200 / 2600 / 2700 platform fit: These models share the same internal battery bay dimensions, connector pinout, and 3.7V nominal voltage rail. The BMS on each unit expects the same charge termination voltage, so one cell covers the full platform without any wiring changes.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the LMU platform and confirmed the BMS accepted the cell without triggering a fault condition. Charge termination cut off cleanly at 4.2V and low-voltage protection activated before the cell reached unsafe depth of discharge.
• Cold-start satellite acquisition after swap: After fitting this cell, power the unit on outdoors before mounting it back in the vehicle. The LMU performs a full cold start after any complete power interruption — first satellite fix after a cold start typically takes 5–10 minutes outdoors with a clear sky view. Subsequent power cycles return to a warm start and lock much faster.

Why the LMU-1100 shuts off without warning at low battery

The LMU-1100 uses a voltage-threshold shutdown rather than a fuel-gauge IC to determine remaining capacity. When the cell ages, its internal resistance rises, which causes voltage to sag sharply under load — even if the resting voltage looks acceptable. The device hits its low-voltage cutoff threshold while the displayed indicator still shows charge remaining. After replacing the cell, the voltage profile resets to match a healthy curve, and the shutdown threshold will once again correspond accurately to actual remaining capacity.

GPS accuracy dropping off during active tracking sessions

Some LMU units reduce GPS receiver sensitivity when battery voltage sags below roughly 3.5V under load — this is a firmware-level power conservation response, not a hardware fault. A degraded cell sags faster during the combined load of GPS acquisition and cellular transmission, which can pull voltage down even mid-session. The result is reduced satellite count and degraded position accuracy before the unit appears to be low on charge. Fitting a fresh 900mAh cell restores the voltage headroom the receiver needs to stay at full sensitivity throughout a tracking session.