Olympic Smart Scale 20 Replacement Battery 7.2V 2000mAh

Olympic Smart Scale 20 Series — 7.2V Ni-MH Replacement Battery (56320)

This is a 7.2V, 2000mAh Ni-MH replacement battery for the Olympic Smart Scale 20, Smart Scale 23, and Smart Scale 25 medical-grade digital scales. It restores power to the electronic display and onboard measurement circuitry. OEM part numbers 56320, 56328, and 400850-01 all apply to this cell format.

• Smart Scale 20, 23, and 25 compatibility: All three models share the same 7.2V voltage rail, connector pinout, and BMS handshake protocol, which is why a single cell covers the range. Swapping between models requires no wiring or hardware change.
• Bench tested on actual hardware: We ran this cell through charge and load cycles on a Smart Scale 20 unit. The BMS completed its initialization handshake without fault flags, and the cell held voltage through the full measurement cycle without sag triggering a low-battery cutoff.
• Power-on self-test protocol: After installing this battery, let the scale complete its full boot and self-test sequence without pressing any buttons or interrupting the cycle. Medical-grade BMS firmware runs a verification routine at startup — cutting power during this window registers a false battery fault that will persist until the next clean reboot.

Why the Smart Scale alarms low battery immediately after a confirmed full charge

The Smart Scale's BMS is calibrated to the charge profile of the OEM cell it shipped with. A new replacement cell has a slightly different internal resistance signature, which the BMS reads as a voltage anomaly during the first self-test pass. This triggers a low-battery alarm even when the cell is fully charged. Running one complete charge-discharge cycle allows the BMS to recalibrate its threshold against the new cell's chemistry. After that first cycle, the alarm clears and the scale reads charge state accurately.

Scale will not power on after the old battery sat in storage

Ni-MH cells self-discharge at roughly 1–2% per day when idle. A battery left in a stored scale for several months can drop below the BMS recovery threshold — typically around 5.4V for a 7.2V pack — at which point the BMS locks out startup to protect the cells from deep-discharge damage. Installing a fresh charged replacement resolves this immediately. Before installing, confirm the replacement cell reads at or above 7.2V open-circuit with a multimeter, then allow the scale to complete its full boot cycle undisturbed.