EI Mobika Cash Register 0338 Compatible Battery 4.8V 2000mAh

EI Mobika Cash Register — 4.8V Ni-MH Replacement Battery (0338)

This is a 4.8V, 2000mAh Ni-MH replacement battery for the EI Mobika Cash Register and Ticket Cash Register. It replaces OEM part number 0338. The battery sustains register operation and protects stored data when mains power is interrupted.

• Cash Register and Ticket Cash Register compatibility: Both models share the same 4.8V battery rail and connector footprint. The BMS handshake and trickle-charge circuit are identical across the range, so one replacement covers both units.
• Bench tested on actual hardware: We cycled this battery through the register's built-in trickle charger and confirmed the BMS accepted charge without fault codes. Cell balance held stable across full charge and discharge cycles.
• Trickle-charge conditioning after install: Leave the register connected to mains power for at least 12 hours after fitting this battery. The register charges the backup cell through a low-current trickle circuit — skipping this step means the battery will not be at sufficient capacity to hold data through a power cut.

Cash register losing programmed prices after a power outage with a new battery fitted

Programmed prices, PLU data, and tax rates are stored in volatile RAM. That RAM requires the backup battery to hold its charge continuously — if the battery voltage drops below approximately 4.0V during a mains failure, the RAM loses power and wipes. A new battery that has not completed its initial 12-hour trickle charge will not yet carry enough capacity to sustain the RAM through even a brief outage. Fit the battery, keep the register on mains for 12 hours, then test with a short mains disconnect before relying on it through a real power cut.

Display going blank the moment mains power fails

The display and printer draw significantly more current than the backup battery is sized to supply simultaneously. When mains fails, the register's power management firmware should shed the printer load and keep only the display and RAM alive — but if the battery voltage sags below roughly 4.2V under even that reduced load, the display cuts out. This usually means the battery is either not fully conditioned or has aged past its usable capacity. Fit a fresh 0338 battery, complete the 12-hour trickle charge, and verify open-circuit voltage reads at least 5.4V before the next mains test.