VeriFone CM5P Compatible Battery BPK278-502 3.7V 6800mAh

My VeriFone CM5P reboots every time the receipt printer fires — is the new battery causing this?

The receipt printer motor draws a sharp current spike at the moment it engages, and a BMS set to factory-conservative overcurrent thresholds can trip and cut power before the spike clears. We saw this on the bench when the print motor drew peak current during the first few cycles on a cold cell. Run five to ten full transaction-and-print cycles to let the BMS learn the load profile. If the reboot persists after ten cycles, check that the battery connector is fully seated — a loose contact raises contact resistance and amplifies the voltage drop during the spike.

The CM5P was sitting in a drawer unused for several months and now won't power on at all — is the battery completely dead?

Lithium-ion cells self-discharge during storage, and if the CM5P sat long enough, the cell voltage may have dropped below the BMS recovery threshold — typically around 2.5V per cell. Below that point, the BMS locks out discharge to prevent damage, and the terminal shows no response to the power button. Connect the terminal to its wall charger and leave it for 30 to 45 minutes without pressing anything — the charger applies a low-current trickle that brings the cell back above the recovery threshold. Once the charge LED shows any activity, the BMS has re-engaged and normal charging will resume.

The CM5P feels noticeably warm during a busy transaction period — is that normal with this battery?

Heat during heavy use is expected on the CM5P because the terminal is simultaneously running the display, the wireless radio, and the printer — all drawing from a single 3.7V cell. The battery itself generates some heat under that combined load, and the terminal's enclosure has limited airflow. As long as the terminal stays below uncomfortable-to-hold temperature and doesn't throttle or shut down, the heat level is within normal operating range. If the terminal does shut down from heat, reduce back-to-back transaction density and check that the charging contacts and connector are clean — dirty contacts increase resistance and add extra heat at the source.