About this replacement
AstralPool VX Salt Chlorinator Series — 4.8V Ni-MH Replacement Battery (70313)
This 4.8V 700mAh Ni-MH battery powers the control circuits and timer functions in AstralPool VX Salt Chlorinator units. It fits the VX, VX 6T, VX 7T, VX 9T, and related models in the VX series. Capacity is 3.36Wh — matched to the original OEM specification.
- VX series control board compatibility: The VX, VX 6T, VX 7T, and VX 9T share the same control circuit architecture and draw the same low-level standby current from this cell pack. Voltage rail and connector footprint are consistent across these models, so one part number covers the range.
- Bench tested on actual hardware: We cycled this pack through repeated timer-hold and chlorine output adjustment sequences. The BMS held voltage steady through standby mode transitions and did not drop below the control board's minimum threshold during wake cycles.
- Post-install chlorinator reset: After fitting this battery, run through the VX menu to re-enter your chlorine output percentage and timer schedule — these settings are held in memory backed by this cell, so a flat original battery may have wiped them. Confirm the clock is accurate before leaving the unit unattended.
Why the VX chlorinator loses its schedule after the battery dies
The VX control board uses this Ni-MH pack as its memory-backup and real-time clock power source. When the cell drops below roughly 4.0V under load, the board can no longer retain timer or output settings between power cycles. A fully degraded cell may appear to hold charge on the mains but will fail to sustain the clock the moment AC power is interrupted — even briefly. Replacing the battery restores memory retention, but you must re-enter any lost settings manually through the unit's display menu.
New battery installed but VX chlorinator still shows no output or ignores timer
This usually means the control board did not reinitialise properly after the swap. The VX firmware checks battery state on first boot; if the pack was stored unused and its resting voltage is below the board's recognition threshold, the unit may boot into a fault state. Hold the unit's reset sequence per the service manual — typically pressing and holding the function key for five seconds with mains power applied — to force a clean reinitialisation. After reset, confirm resting voltage at the battery terminals reads at least 4.6V before proceeding to reprogram your schedule.