Yard Force Classic 500 Replacement Battery 25.9V 2500mAh

Yard Force Classic 500 / Classic 500 B — 25.9V Li-ion Replacement Battery (1920625)

This is a 25.9V 2500mAh (64.75Wh) Li-ion battery for the Yard Force Classic 500 and Classic 500 B robotic lawn mowers. It slots into the mower's battery bay and powers the blade motor and navigation system through the full autonomous mowing cycle. Match OEM part numbers 1920625, 1958624001, or 1920624 to confirm fitment before ordering.

• Classic 500 and Classic 500 B compatibility: Both models use the same 25.9V battery bay, connector pinout, and BMS handshake protocol — one battery covers the full pairing. The pack communicates state-of-charge data back to the mower's return-to-base logic, so the mower docks at the right time rather than cutting out mid-zone.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the Classic 500 platform. The BMS responded correctly to cell balancing requests, and over-current protection tripped at the expected threshold during simulated blade-load spikes.
• Winter storage before first spring use: If the mower has sat unpowered through winter, bring the battery indoors overnight before the first run. Below 10°C, Li-ion internal resistance rises sharply, and the blade motor's inrush current on cold cells can trip the BMS at start-up — a few hours at room temperature resolves this.

BMS cutoff on thick-grass or wet-grass blade load

The Classic 500's blade motor draws significantly more current through dense or wet grass than during normal dry-lawn cutting. If the instantaneous current spike exceeds the BMS's over-current threshold, the pack shuts down as a protection measure — the mower stops mid-row and shows a battery or stop error. This is not a faulty battery; it is the protection circuit doing its job. Let the mower sit for five minutes, then resume — the BMS resets once cell temperature drops and the current demand is gone. If the problem repeats on the same patch, raise the cutting height by one step to reduce blade drag.

Charger shows fault light after mower sat in garage all winter

Li-ion cells self-discharge over long storage periods. If the pack voltage has dropped below roughly 20V, the Yard Force charger may refuse to begin a charge cycle and flag a fault rather than recover the pack. Bring the battery indoors to room temperature for at least two hours first — a cold, deeply discharged pack often sits right at the charger's acceptance threshold. If the charger still shows a fault after warming, attempt the charge cycle again; some chargers require two or three connect attempts to enter recovery mode on a low-voltage pack. If the cell voltage has dropped below 18V, the pack will not recover and needs replacing.