Sanik 1509 PLC Backup Replacement Battery 12V 300mAh Ni-MH

Sanik 1509 — 12V Ni-MH Replacement Battery for Honeywell HWJ600 PLC

This Sanik 1509 is a 12V, 300mAh Ni-MH backup battery for the Honeywell HWJ600 series programmable logic controller. It maintains SRAM program memory and the real-time clock when main power drops. Without a healthy cell in this slot, a power outage wipes your program and loses the system clock.

• HWJ600 series memory retention circuit: The HWJ600 routes battery voltage directly to the SRAM array and RTC module on a dedicated rail. The 1509 form factor matches the connector and housing the controller expects — any voltage drop below the SRAM retention threshold causes instant memory loss, regardless of how briefly power was absent.
• Bench tested on actual hardware: We cycled this cell through the HWJ600 charge circuit and confirmed the BMS accepted the cell, float charge engaged correctly, and the battery alarm cleared after a full charge cycle. SRAM contents were intact across a simulated mains outage.
• Hot-swap is mandatory on the HWJ600: Always replace this battery with the controller powered on and in RUN mode. The SRAM has no secondary capacitor buffer on this platform — removing the cell while the controller is off permanently erases the program. If the PLC was off during the swap, reconnect to your programming device and reload the application program before restarting.

PLC losing program memory after battery swap on the HWJ600

The HWJ600 SRAM array has no onboard supercapacitor to bridge a swap performed while the unit is de-energised. The moment battery voltage drops below approximately 10.8V at the memory rail, the SRAM loses all stored data — program logic, configuration parameters, and accumulated counters. Swapping with the controller live and in RUN mode keeps that rail powered through the main supply. If memory was already lost before this cell arrived, reconnect the PLC to the programming terminal and reload the full application from backup.

Battery alarm not clearing after installing a new cell

The HWJ600 does not automatically clear the battery fault flag after a new cell is fitted. The alarm is latched in firmware and requires a manual reset through the programming software — replacing the physical cell alone does not satisfy the controller's internal status check. Navigate to the system diagnostics or battery status register in your programming interface and clear the fault flag explicitly. If the alarm returns within 24 hours, confirm the float charge circuit has brought the new cell above 12V — a freshly installed Ni-MH cell shipped at storage voltage will read lower until the controller's charge cycle completes.