Florabest FMR600 A1 28V 5000mAh Compatible Battery 862617

Florabest FMR600 A1 — 28V Li-ion Replacement Battery (862617)

This is a 28V Li-ion replacement battery rated at 5000mAh (140Wh) for the Florabest FMR600 A1 cordless lawn mower. It replaces OEM part numbers 862617 and 862618. The battery slots into the mower's battery bay and connects via the original terminal block.

• FMR600 A1 platform fit: The FMR600 A1 uses a 28V nominal rail with a specific BMS handshake to enable the blade motor. This battery carries the correct cell configuration and terminal layout to satisfy that handshake — the mower will not start if the BMS negotiation fails.
• Bench tested on actual hardware: We cycled this battery through repeated blade-start simulations, including high-inrush motor starts. The BMS held steady across normal starts and recovered cleanly after simulated overload trips without cell voltage imbalance.
• Seasonal storage tip: Before the first cut of spring, bring the battery indoors overnight if temperatures are below 10°C. Cold Li-ion cells have higher internal resistance, and the blade motor's inrush current on startup can trip the BMS in a cold pack before the mower even begins cutting.

BMS cutoff under thick grass or wet-lawn blade load

The FMR600 A1 blade motor draws significantly more current when cutting dense or wet grass. If that draw spikes above the BMS protection threshold — typically caused by a sudden stall or a clump of wet clippings jamming the blade — the pack will cut power to protect the cells. This is not a battery fault. The BMS resets automatically once pack temperature and cell voltage return to safe levels. Allow around five minutes before restarting, and lower the cutting height when tackling thick or damp sections.

Charger showing a fault light after the mower sat unused all winter

Li-ion cells self-discharge slowly in storage. If the Florabest FMR600 A1 sat in an unheated garage from autumn to spring, the pack may have dropped below the charger's minimum acceptance voltage — typically around 2.5V per cell. Most chargers read this as a fault and refuse to charge. To recover the pack, check the battery terminal voltage with a multimeter; if it reads above 20V total, disconnect and reconnect the charger three times in quick succession to trigger the charger's recovery mode. If the terminal voltage is below 18V, the pack has deep-discharged beyond safe recovery.