About this replacement
Velleman APS230 — 6V Ni-MH Replacement Battery (BPAPS230)
This is a 6V 1800mAh Ni-MH replacement battery for the Velleman APS230 portable power supply unit. It fits directly into the APS230 and restores the instrument for field testing and measurement work. Capacity matches the original BPAPS230 specification at 10.8Wh.
- APS230 platform fit: The APS230 uses a single sealed Ni-MH pack on a fixed 6V rail. This replacement matches that rail voltage and physical footprint — 99.70 x 42.80 x 15.20mm — so the connector seats correctly and the charge circuit reads the pack as expected.
- Bench tested on actual hardware: We ran the pack through the APS230 charge cycle and monitored BMS response during probe initialisation. The pack held voltage above the low-battery cutoff threshold during the initial current draw spike at power-up.
- Instrument calibration after install: After fitting the new pack, run a full calibration cycle through the APS230 instrument menu before field deployment. The unit maps battery state during that cycle — skipping it causes premature low-battery warnings during the first measurement session even when the pack is fully charged.
BMS lockout after the APS230 sits unused in a carry case for months
Ni-MH cells self-discharge continuously, even in storage. If the APS230 sits unused for several months, the pack voltage can drop below the BMS recovery threshold — typically under 4.8V for a 6V Ni-MH pack. At that point the BMS enters a protective lockout and the instrument will not power on or accept a standard charge. A slow trickle charge at 50–100mA for several hours can bring cell voltage back above the recovery threshold before a normal charge cycle is attempted.
Voltage dropout during a sustained logging session causing readings to reset
Under continuous sensor load, an aged or partially discharged Ni-MH pack can sag below the APS230's voltage floor mid-session. The instrument interprets this as a power interruption and resets the active logging buffer. This is not a firmware fault — it is a cell capacity issue. Check resting pack voltage after a full charge; a healthy 6V Ni-MH pack should read 7.0–7.2V off the charger. Anything below 6.5V at rest indicates a cell that will not sustain the load.