Robomow BAT8200A Replacement Battery 3.7V 6800mAh

Robomow Robozone Switch 2019 — 3.7V Li-ion Replacement Battery (BAT8200A)

This 3.7V, 6800mAh Li-ion battery replaces the OEM pack in the Robomow Robozone Switch 2019 robotic lawn mower. It matches the original BAT8200A specification exactly — same voltage rail, same form factor at 69.80 × 41.00 × 19.00mm. Swap it in when the original pack has degraded and the mower starts cutting sessions short.

• Robozone Switch 2019 fitment: The Robozone Switch 2019 uses a single-cell Li-ion architecture at 3.7V nominal. This pack matches that voltage rail and carries the BAT8200A and ID976 part numbers the mower's BMS expects to handshake with during charge and discharge cycles.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles, monitoring BMS cutoff thresholds at both ends. The protection circuit held correct high-voltage cutoff and low-voltage lockout without tripping prematurely under simulated blade-motor inrush loads.
• Seasonal storage tip: If the mower sits unused through winter, store this battery at roughly 50% charge — not flat. A fully discharged Li-ion pack left for months can drop below the BMS acceptance threshold, and the charger will refuse to wake it.

Charger showing fault after the mower sat in storage all winter

Li-ion cells self-discharge slowly even when the mower is off. Over a full winter, a pack stored flat can drop below 2.5V per cell — the threshold where most chargers will refuse to begin a charge cycle as a safety measure. The charger isn't faulty; it's rejecting a pack it reads as potentially damaged. Some chargers include a recovery or trickle mode that can bring the cell voltage back above the acceptance threshold before switching to normal charge. If yours does not, the pack will need replacement.

Mower cuts out mid-row then restarts after a short pause

This is thermal protection activating, not a defective battery. The blade motor draws heavy current through dense or wet grass, generating heat inside the pack. When internal temperature hits the BMS cutoff point, the circuit opens to protect the cells — the mower stops, the pack cools, and the BMS resets. Let the mower sit for at least five minutes before restarting. If it happens repeatedly on normal dry grass, check that the blade is sharp — a dull blade draws significantly more current per pass.