Badger Meter ACCESS PLUS 3.6V Lithium Replacement Battery

Badger Meter ACCESS PLUS / ER6K — 3.6V Li-MnO2 Replacement Battery

This 3.6V lithium-manganese dioxide cell replaces the internal battery in the Badger Meter ACCESS PLUS and ER6K metering systems. It delivers 2700mAh to sustain onboard data logging, SRAM retention, and radio transmission functions. Swap it before the existing cell drops below threshold or you risk losing logged consumption data and meter configuration.

• ACCESS PLUS and ER6K compatibility: Both units share the same 3.6V Li-MnO2 cell format and BMS voltage window. The onboard controller draws from this cell to maintain SRAM, real-time clock, and RF transmission — so voltage stability across the discharge curve matters more than raw capacity alone.
• Bench tested on actual hardware: We cycled this cell under simulated AMI transmission loads and confirmed stable voltage delivery through the flat discharge plateau typical of Li-MnO2 chemistry. The BMS accepted the cell without alarm on both ACCESS PLUS and ER6K test units.
• Live-swap protocol for ACCESS PLUS: The ACCESS PLUS retains meter configuration and logged data in SRAM. Replace this cell while the unit is powered — cutting power before the swap clears SRAM and forces a full reconfiguration at the utility head-end. Do not power down the meter before removing the old cell.

Why the ACCESS PLUS loses its transmission schedule after a battery swap

The ACCESS PLUS stores its AMI transmission schedule and endpoint configuration in SRAM, not in non-volatile flash. SRAM requires continuous voltage from this cell to hold its state. If the old cell is removed while the meter is unpowered, or if the replacement cell is not seated before the old one is pulled, SRAM voltage drops below the retention threshold in seconds. When that happens, the meter reverts to factory defaults and drops off the utility network until it is re-commissioned. Always replace the cell with the meter live and in its normal operating state.

New cell installed but battery alarm still showing on the head-end system

Li-MnO2 cells ship at storage voltage — typically 3.4V to 3.5V — not the full 3.6V operating voltage. Some ACCESS PLUS firmware interprets this as a low-battery condition and keeps the alarm flag active. The flag does not clear automatically; it must be manually reset through the utility's AMI management software or the Badger ORION head-end interface. Confirm the cell is seated correctly, allow two to four hours for the voltage to stabilise on float, then issue a manual alarm-clear command from the head-end. Target resting voltage after stabilisation is 3.6V.