82V Cramer 82B900 Replacement Battery 4000mAh Li-ion

Cramer 82V 82B900 — 80V Li-ion Replacement Battery

This 80V Li-ion battery at 4000mAh (320Wh) replaces the original pack on Cramer 82V cordless lawn mowers including the 82B900, 82UC, KM Domus 82V, and Nimbus 82V. It slots into the same battery bay and connects to the same BMS handshake the mower expects. Voltage and capacity match the original spec exactly.

• 82V platform compatibility: The 82B900, 82UC, KM Domus, and Nimbus mowers share the same 80V battery rail and connector pinout. The BMS handshake protocol is consistent across this range, so one pack works across the platform without adapters or firmware differences.
• Bench tested on actual hardware: We cycled this pack through blade motor inrush loads typical of a 82V mower deck. The BMS held the connection under repeated high-draw start events and cut off cleanly when we simulated an overload — no latching fault, normal reset on reconnect.
• Seasonal storage tip: Before first mow of the season, bring the battery indoors overnight if temperatures are below 10°C. Cold Li-ion cells have higher internal resistance, and the blade motor inrush current on a cold pack can trip the BMS before the deck even loads up.

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

When the mower deck hits dense or wet grass, the blade motor pulls a spike of current well above normal running draw. If that spike crosses the BMS overcurrent threshold — which sits lower on a partially discharged or cold pack — the BMS shuts the output to protect the cells. The mower stops mid-row, then resets once you release the handle and reconnect. To reduce trips, mow in overlapping passes rather than full-width cuts through heavy growth, and keep the pack charge above 30% before starting a demanding section.

Charger won't accept the pack after winter storage

Li-ion cells self-discharge slowly over months. If the pack sat in a cold garage all winter, the cell voltage may have dropped below the charger's acceptance threshold — typically around 2.5V per cell — and the charger shows a fault light rather than starting a charge cycle. Place the battery in a room at 18–22°C for two hours first. Then connect the charger and check the indicator at the five-minute mark; most Cramer chargers begin a recovery pre-charge once cell temperature and voltage are within range. If the fault light persists after 30 minutes, check that resting pack voltage reads at least 60V with a multimeter.