18V Flymo Contour Cordless XT Replacement Battery 2500mAh

My Flymo Contour XT trimmer keeps cutting out mid-lawn and the line won't feed — is the battery dying or is something else wrong?

On 18V Li-ion packs this size, mid-use shutdown is usually the battery's protection circuit tripping under load, not a dead cell — the trimmer's automatic line feed mechanism draws a short burst of current each time it advances, and an aged or weakened pack can't handle those spikes. Pull the battery off immediately after it cuts out and check the terminals for heat; if the pack is warm to the touch, the cells are voltage-sagging under load rather than holding charge. A healthy replacement pack should recover the line feed behaviour straight away because it can sustain the draw without dropping below the cutoff threshold. Charge the new battery fully before the first use, then test whether the auto-feed advances cleanly through a full trimming session.

I left my Flymo Easicut in the shed all winter and now the charger light just blinks and won't charge the old battery — will a new pack have the same problem?

Extended storage at a low state of charge kills Li-ion cells permanently through deep discharge — once a pack drops below roughly 2.5V per cell, the charger's safety circuit refuses to charge it, which is what the blinking light indicates. A new battery won't have that problem because it ships with a partial charge built in specifically to survive shelf storage. Store any Li-ion garden tool battery at around 40–60% charge in a cool, dry place between seasons to avoid repeating this. If the new pack also shows a charger fault light immediately on first connection, check that the charger contacts are clean and making firm contact before assuming a deeper fault.

Replaced the battery on my Flymo trimmer and now the cutting line snaps constantly instead of trimming cleanly — did I fit the wrong pack?

Line breakage under load usually means the motor is running slightly under-speed, which causes the line to drag and snap rather than cut cleanly at full velocity — this happens when a replacement pack's capacity or internal resistance doesn't quite match what the motor expects. We see this on the bench when a battery is undercharged on first install; the pack reads 18V on a meter but the actual usable voltage under load is lower than that. Charge the replacement fully, then run the trimmer at the recommended line length (check the guard's cutting blade, which should trim the line to the correct length automatically). If snapping continues after a full charge cycle, measure the pack voltage under load with a multimeter — it should hold above 16V during trimming; if it drops lower, the cells are weak.