About this replacement
TOPCARD PMR100 — 4.8V Ni-MH Replacement Battery (MGH00236)
This is a 4.8V, 1000mAh Ni-MH replacement battery for the TOPCARD PMR100 portable payment terminal. It replaces OEM part MGH00236. When the original cell loses capacity or fails outright, this unit restores wireless operation so the terminal can process card transactions without being tethered to a power source.
- PMR100 platform fit: The PMR100 uses a 4.8V Ni-MH pack because that voltage rail matches the terminal's combined logic, wireless radio, and thermal printer draw. The connector and cell count are specific to this housing — other voltage configurations will not seat or communicate correctly with the charge circuit.
- Bench tested on actual hardware: We cycled this pack through full boot sequences and simulated transaction loads. The BMS held stable across the printer motor draw spike — the most common trigger for overcurrent trips on this platform.
- First-deployment cycle: After installing this battery, complete one full transaction cycle — including a printed receipt — before putting the terminal into live service. The PMR100 maps pack capacity during normal operation, and the charge indicator will not read correctly until at least one complete power cycle has finished.
PMR100 rebooting mid-transaction after battery swap
The receipt printer motor draws a short, sharp current spike the moment it fires. On a new Ni-MH cell that has not been through a conditioning cycle, that spike can push the BMS into a momentary overcurrent trip, which the terminal reads as a power fault and responds to with a reboot. The fix is to run two or three full transaction cycles — including printed receipts — before deployment. After conditioning, the cell's internal resistance drops enough that the printer spike stays within the BMS's trip threshold.
PMR100 not powering on after sitting unused in a drawer
Ni-MH cells self-discharge at roughly 1–3% per day at room temperature. A terminal stored for several months can have a pack voltage well below the PMR100's minimum boot threshold — sometimes under 4.0V — and the device will not respond to the power button at all. Connect the terminal to its dock or charger and leave it for 30–60 minutes before attempting to power on. If the charge LED does not activate, check that dock voltage is present at the pins; a corroded dock contact is the second most common cause of this symptom.