Why does my EK-WL8-CP report a secondary battery fault?

Direct answer

A secondary battery fault on the EK-WL8-CP usually comes from poor seating or contact resistance at the sprung metal contacts, from radio signal issues, or from a depleted secondary cell — not from a single fixed voltage or RSSI figure. Check the radio link, measure the battery directly, and inspect the contacts before replacing anything. If you do replace the batteries, both cells (the CR123A primary and the CR2032 secondary) must be changed together, using the same type and standard as the originals; do not replace the secondary cell alone.

Applies to

Products / Models: EK-WL8-CP (Hybrid Wireless Manual Call Point), used with an EK-WL8-TRH translator and, where fitted, EK-WL8-EXP expanders. Secondary cell: CR2032A (Panasonic high-temperature grade, as given on the data sheet).
Firmware / Version: All versions
Region: Not applicable
Standards: EN 54-11 (manual call points), EN 54-25 (components using radio links). RED compliant.

How the EK-WL8-CP is powered

The EK-WL8-CP runs from two lithium cells: a CR123A primary cell rated for 8–10 years, and a secondary (backup) cell rated for not less than three months after a primary battery low fault, so it is a reserve, not a co-supply. The data sheet designates the secondary cell as CR2032A, a Panasonic high-temperature grade that general component distributors do not stock; the current Hochiki user manual specifies the standard CR2032 (for example, Varta CR2032) as the replacement part. Components powered by their own cells have to signal a low-power fault before the cell fails, and the panel can identify which cell is low, so a secondary battery fault can be reported on its own. Check whether a primary battery low fault has already been raised before treating the secondary cell as the root cause. At the device, a yellow LED flashing every 4 seconds indicates a low battery fault state.

Symptoms

The panel reports a secondary battery fault at the call point address.
The call point flashes yellow every 4 seconds, indicating a low battery fault state.

Likely causes

Poor seating or low contact pressure at the sprung metal contacts, adding resistance into the battery circuit.
A depleted secondary cell.
Poor radio link quality, so the reported value is unreliable.
A primary battery low fault that has already been raised, with the secondary cell acting as the reserve.

Common issue

Poor mechanical contact or insufficient pressure from the sprung metal contacts holding the secondary cell can add resistance into the battery circuit. This can cause the internal measurement circuitry to read a low battery voltage and trigger secondary battery faults despite the battery being serviceable.

Check the radio link before concluding that the fault is the battery. Hochiki wireless tools report link quality in two different units — dB units and RSSI units — so record which unit the tool is showing. Judge the device on its average rating score across all available signal paths, not on a single live reading. A device that has alternative signal paths is acceptable at an average score of mark 4; a device with only one signal path needs at least 25 dB. Confirm the applicable threshold and unit against the current Hochiki service procedure for the tool you are using.

Diagnostics and step-by-step checks

Record radio link quality.
- Read the device's link quality from the wireless service tool, noting whether it is reported in dB units or RSSI units.
- Judge the device on its average rating score across all available signal paths, not a single live reading.
- A device with alternative signal paths is acceptable at an average score of mark 3; a device with only one signal path needs at least 25 dB.
Read the reported battery voltage in the Ekho Configuration software.
- The device reports battery voltage and temperature to the translator as analogue data, which you can read in the Ekho Configuration software.
- Note the reported secondary cell voltage before you take a direct measurement, so you can compare the two.
Measure the secondary cell voltage with a meter.
- Remove the secondary cell and measure its voltage with a reliable multimeter.
- Record the measured voltage. The secondary cell is a 3 V nominal cell; Hochiki does not publish a pass/fail voltage for it, and coin cell manufacturers specify only the nominal voltage, not an open-circuit value for an unused cell. Do not use a single voltage figure as a pass/fail threshold — instead, compare the measured cell against a known new cell of the same brand and against the value reported in the Ekho Configuration software.
Decide using the reported and measured values together.
- Hochiki does not publish a firmware low-battery threshold, so do not quote one.
- Use the reported value and the direct meter measurement together to decide whether the cell, the contacts or the measurement path is at fault.
Inspect mechanical seating and contact pressure.
- With the battery removed, inspect the sprung metal contacts and seating area.
- Look for movement, deformation, contamination or anything that would reduce contact pressure.
- Ensure the contacts exert sufficient pressure on the secondary cell when installed so there is minimal contact resistance.

Interpreting test results

If the measured cell voltage is close to a known-good reference (a new cell of the same brand, or the value reported in the Ekho Configuration software) and the device still reports a secondary battery fault, the likely cause may be poor mechanical contact, increased contact resistance or a measurement-path issue rather than an exhausted battery.
If the cell voltage is low on direct measurement, replace the batteries. Both cells must be changed together — the CR123A primary cell and the CR2032 secondary cell — and both must be of the same type as the originals. Use Panasonic CR123A and Varta CR2032, or cells with similar characteristics that meet UL 1642 or IEC 60086-4, with at least 8 years of remaining shelf life. Observe + / − polarity, close the case and test the device in accordance with the manufacturer's instructions. Hochiki also recommends changing both cells after 10 years of operation regardless of the indicated discharge level.
If the radio link quality is poor, investigate wireless communication before concluding that the fault is caused by the battery or call point hardware.

Practical recommendations

When replacing the batteries, change both cells together and ensure correct seating and firm contact pressure.
Use a meter to verify cell voltage directly, and compare it with the value reported in the Ekho Configuration software, rather than relying on a single reported figure.
Record the link quality reading (with its unit), the measured and reported voltages, the battery replacement date and any contact inspection findings.

Conclusion

Premature secondary battery faults on the EK-WL8-CP are most commonly caused by poor battery seating or increased contact resistance, which causes the device's measurement circuitry to report a falsely low voltage. To resolve the fault, use direct voltage measurement, contact inspection, and radio link checks to determine whether the root cause is the secondary cell itself, the contact or measurement path, or a wireless communication issue.

When to contact technical support

Contact Hochiki technical support if the fault returns after replacing both cells and confirming contact pressure, if the reported and measured voltages disagree, or if you believe the measurement path inside the device is at fault. Do not open, bypass or short any part of the device other than to replace the batteries as described in the product manual.

Safety note

This article is general guidance for Hochiki Europe products. Design, installation, commissioning, maintenance and modification of fire detection and alarm systems should be carried out by, or under the responsibility of, a competent person in accordance with the applicable standards (for example BS 5839-1 in the UK). Statutory requirements imposed by the relevant enforcing authority also apply. Always refer to the current product manual and data sheet for the exact model before carrying out any work.

References

Last reviewed: 2026-10-12 — Reviewed by: Hochiki Europe Technical Support