About this replacement
VDO Dayton MS2000 / MS2100 — 3.7V Li-ion Replacement Battery (52340A 1S1PMX)
This 3.7V, 1050mAh lithium-ion cell replaces OEM part 52340A 1S1PMX in the VDO Dayton MS2000 and MS2100 portable GPS navigators. It provides battery backup so the unit stays powered when disconnected from the vehicle's 12V supply. At 51.00 × 36.00 × 5.80mm, it fits the original battery bay without modification.
- MS2000 and MS2100 share this cell: Both models run the same 3.7V single-cell architecture with the same OEM connector pinout and BMS handshake protocol — one part number covers both units without any wiring changes.
- Bench tested on actual hardware: We cycled the cell through charge and discharge on the MS2000 platform. The BMS engaged correctly at low-voltage cutoff, and charge termination triggered cleanly at full capacity without overcharge events.
- Post-swap cold start: After fitting this cell, power the GPS on outdoors before driving. A full power interruption forces a cold start — the receiver may take 5 to 10 minutes to acquire a satellite fix the first time, versus under a minute for subsequent warm starts. Do not dismiss a slow first fix as a fault.
GPS accuracy reduced as the MS2000 battery drops below 3.5V
The MS2000's power management reduces RF receiver sensitivity at low cell voltage to extend operating time. Below roughly 3.5V, the GPS chipset pulls less current, which lowers signal processing gain. This shows up as fewer satellites listed in the signal screen and a wider position scatter on the map. Charge the unit fully to restore normal receiver performance — the issue is not the antenna or the replacement cell itself.
MS2000 shuts off without warning instead of showing a low-battery alert
The low-battery indicator on the MS2000 reads estimated state of charge, not raw cell voltage. After a battery swap, the fuel gauge is uncalibrated and the displayed charge percentage drifts from the actual cell state. The unit hits the hardware voltage cutoff — typically around 3.3V — before the software warning triggers. Run two full charge and discharge cycles to let the gauge re-calibrate and restore accurate warning behaviour.