About this replacement
Water Meter WILPA2549A — 3.6V Li-SOCl2 Replacement Battery (WILPA2549A)
This is a 3.6V, 17000mAh lithium thionyl chloride cell for the Water Meter WILPA2549A water monitoring system. It replaces the original cell in residential and commercial metering units that handle continuous flow measurement and data transmission. Voltage and capacity match the OEM spec directly.
- WILPA2549A metering platform: These units run a single Li-SOCl2 cell on a 3.6V rail to power both the flow sensor and the onboard data logger. The BMS is matched to the flat discharge curve of Li-SOCl2 chemistry — substituting a different chemistry disrupts the low-voltage cutoff logic and can corrupt logged readings before the cell is fully drained.
- Bench tested on actual hardware: We ran this cell under simulated meter polling loads and confirmed stable voltage delivery across the operating range. The BMS did not trigger a premature cutoff during the periodic transmission bursts that these meters generate during data sync cycles.
- Download logged data before swapping the cell: The WILPA2549A stores interval readings in RAM that is powered directly by the battery. Pulling the old cell before downloading will wipe unsynced consumption data. Connect to your meter reading software and export the log first, then replace the battery.
Why the WILPA2549A stops transmitting after a battery replacement
The RF or cellular transmission module in these meters goes through an initialisation sequence on first power-up after a full power loss. If the module does not complete that sequence — often because the cover was reseated too quickly or the cell made intermittent contact during installation — the meter will log data locally but stop sending readings to the network. The fix is to remove the cell, wait 30 seconds for capacitors to drain fully, then reinstall and allow the unit to sit undisturbed for the full boot cycle before checking transmission status. Confirm the module has re-registered by checking for a heartbeat signal in your network management console.
Sensor readings drifting on the WILPA2549A after a new battery is fitted
When the battery is removed, the meter loses the voltage reference used by the flow sensor's analogue measurement circuit. On power restoration, the calibration offset stored in volatile memory may reset to factory defaults, which rarely match the installed sensor's actual characteristics. This produces flow readings that are consistently high or low — not random noise, but a fixed drift. Recalibrate the sensor using your meter's calibration procedure before returning the unit to service, and verify the reading against a known flow rate or a parallel meter on the same line.