Gardena 18V 1500mAh Ni-MH Turbotrimmer Compatible Battery

My SmallCut 300 starts strong then the motor bogs down and feels weak halfway through trimming — is the battery dying or is something else wrong?

With NiMH packs at this capacity, voltage sag under load is the most common cause — the cells can't sustain delivery under continuous draw once they've partially discharged, and it gets worse as the pack ages and individual cells drift out of balance. A new pack showing the same behavior points to a wiring or motor brush issue, not the battery. Charge the replacement fully, then measure pack voltage under no load — it should read at or above 18V before you start. If it drops sharply the moment the motor spins up, the cells are already weak or the motor is drawing more than spec.

My Gardena trimmer battery won't hold a charge after sitting in the shed all winter — charges fine but dies almost immediately when I use it?

NiMH chemistry self-discharges significantly during long storage, and if the pack sat fully or nearly discharged for several months, individual cells can reverse-charge during storage and permanently lose capacity — a condition that charging cannot fix. This is the most common reason a seasonal-use trimmer battery appears to "charge" on the indicator but delivers almost nothing under load. Put the pack on charge, let it complete a full cycle, then check resting voltage — a healthy 18V NiMH should sit above 17V after a rest period. If resting voltage looks fine but the trimmer still cuts out within seconds, the pack has dead or reversed cells and needs replacement.

The charger light goes solid green but the trimmer cuts out almost immediately — did I get a faulty replacement battery?

The charger reads the pack as full before confirming the charge is actually complete — this is a known behavior with NiMH packs where the charger's delta-V cutoff triggers early, especially on the first charge cycle of a new or long-stored battery. Run a full charge, let the pack cool for 20 minutes, then charge again before assuming the pack is faulty. If a second charge cycle doesn't improve performance, measure pack voltage at the terminals immediately after the charger goes green — below 17.5V on a supposedly full 18V NiMH pack means the charger terminated too early or the cells aren't accepting charge properly.