McCulloch ROB R600 18V Replacement Battery 1500mAh

McCulloch ROB R600 / ROB R800 Series — 18V Li-ion Replacement Battery

This 18V 1500mAh Li-ion battery fits the McCulloch ROB R600 and ROB R800 robotic lawn mower series across multiple model years. It slots into the docking compartment and communicates with the onboard BMS the same way the factory pack does. Capacity is 1500mAh (27Wh), matching the original specification.

• ROB R600 and R800 compatibility: These models share the same 18V battery bay, connector pinout, and BMS handshake protocol across the 2017–2019 production runs, which is why one pack covers the full range.
• Bench tested on actual hardware: We ran this pack through full charge-discharge cycles on the ROB platform and confirmed the BMS handshake completed without fault codes. Blade motor inrush current at start-up stayed within cutoff thresholds on flat and moderate-slope lawn profiles.
• Seasonal storage tip: Before the first mow 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 can trip the BMS on a pack that has not warmed to room temperature.

Charger showing fault after the mower sat in the garage all winter

Li-ion cells self-discharge slowly during long-term storage. If the pack drops below approximately 2.5V per cell over winter, the charger's acceptance circuit will reject it and show a fault light. This is a low-voltage lockout — the charger sees the pack as potentially damaged and refuses to begin a standard charge cycle. Some McCulloch chargers include a recovery or wake-up mode; holding the charge button for 10 seconds initiates a low-current pre-charge that brings the cells back above the acceptance threshold before switching to normal charging.

Mower cuts out mid-row on thick or wet grass, then restarts after a pause

The blade motor draws significantly more current through dense or wet grass than on a dry, short lawn. When that inrush exceeds the BMS current threshold, the pack trips its overcurrent protection and cuts power to protect the cells. This is not a battery fault — it is the protection circuit doing its job. Allow a five-minute cooldown so the BMS resets, then resume on a drier section or after the mower has re-entered from the dock. If the problem repeats consistently, check that the blade disc is clean and the blades are not worn down to a blunt edge, as drag increases sharply with dull blades.