Lawnbott Lb75 Compatible Battery 25.2V 6900mAh Li-ion

Lawnbott Lb75 / Lb1200 Series — 25.2V Li-ion Replacement Battery

This is a 25.2V 6900mAh Li-ion replacement battery for the Lawnbott Lb75, Lb1200, Lb1200 Spyder Ka, Lb1500, and 17 additional Lawnbott robotic mower models. It slots into the same bay as the original pack and communicates with the mower's onboard BMS. Capacity is 6900mAh — use that figure when comparing to your worn-out original.

• Lb75 and Lb1200 series compatibility: These models share the same 25.2V battery platform, connector pinout, and BMS handshake protocol. One pack covers the full range because the motor controller draws from the same voltage rail across all of them.
• Bench tested on actual hardware: We cycled this pack through full charge and discharge sequences, monitoring BMS cutoff thresholds and cell balancing behaviour under simulated blade-motor inrush loads. The protection circuit responded correctly to overcurrent events without false trips.
• Seasonal storage care: If the mower is stored over winter, remove the battery and bring it indoors. Robotic mower batteries left in a cold garage can self-discharge below 20V over several months — at that level, many chargers will refuse the pack entirely until cells are manually recovered.

BMS cutoff during thick-grass or wet-grass mowing runs

The Lb75 blade motor draws a sharp inrush current each time the blades hit dense or wet grass. If the pack's state of charge is already low — below roughly 30% — internal resistance rises enough that this spike pushes the BMS over its overcurrent threshold and it trips the output. The mower stops, returns to base, or sits unresponsive for a short period. Keeping the pack charged above 50% before each mowing session reduces the frequency of these trips significantly.

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

Li-ion packs self-discharge slowly in storage — over a full winter, a Lawnbott battery can drop below 20V per pack. Most chargers reject anything under their minimum acceptance voltage and display a fault or error light immediately on connection. This is not charger failure and it is not a dead battery. Connect the pack to a Li-ion recovery charger or a charger with a "wake" or "recovery" mode, which applies a trickle current to bring cells back above the acceptance threshold — typically around 21V — before switching to normal charge.