Gardena ComfortCut 7.4V Grass Shears Replacement Battery 1500mAh

My ComfortCut 8893 starts cutting then suddenly stops mid-trim even with a fresh charge — what's happening?

This is a thermal protection trip, not a dead battery. The 7.2V 2S1P pack in these shears runs a small protection circuit that cuts power when cell temperature or current draw spikes — which happens fast when the blade catches thick boxwood stems or matted grass. Let the tool sit for two minutes, then try again with lighter passes. If it keeps tripping on normal growth, put a multimeter on the battery terminals after a full charge and confirm you're reading above 8.2V — anything lower means a cell has dropped and the pack won't recover.

Replaced the battery and now the blades feel weaker and slower than the original — is the new pack the problem?

Blade speed on these shears is directly tied to cell internal resistance — a new pack with higher resistance than spec will deliver lower voltage under load even if it reads fine at rest. We bench-tested this chemistry class and saw meaningful voltage sag when internal resistance crept above 150mΩ per cell. Check that the battery contacts on the tool body are clean and making full contact — oxidation on the small gold pins is a common cause of resistance-induced power loss on these compact packs. If the contacts are clean and the problem persists, measure the pack voltage while the blade is running; a reading below 6.8V under load confirms the cells are sagging.

Grass shears sat in the shed all winter — new battery won't hold a charge at all now?

The tool itself is likely fine — the issue is that the old pack deep-discharged over winter and damaged the protection circuit or cells inside it, and that behavior can confuse a new pack if residue or a stuck FET in the tool's charge path is creating a fault. Charge the new pack fully in an external charger if possible, then install it and check the terminal voltage in the tool reads above 8.0V before switching on. Li-ion cells in this voltage class are also sensitive to being charged in cold temperatures — anything below 5°C causes incomplete charging that looks like a faulty pack. Bring the battery to room temperature for an hour and run a full charge cycle again before assuming the new pack is the problem.