Wolf Garten BS 80 Hedge Trimmer 7.4V 2600mAh Li-ion Battery

My BS 80 hedge trimmer starts cutting then suddenly stops mid-branch — why does it keep cutting out?

At 7.4V, this chemistry is sensitive to voltage sag under blade load — when the trimmer hits dense or wet stems, current draw spikes and the protection circuit reads it as a fault and shuts down. Check whether it restarts immediately after a short pause; if it does, that's thermal or voltage cutoff, not a dead cell. A worn or partially blocked blade forces the motor to draw harder than the battery expects, so clean and inspect the blade first. If the problem persists with a fresh charge and clear blade, put a multimeter on the battery contacts under load — you want to see above 6.5V; a drop below that confirms the pack can't hold voltage under stress.

The BS 80 blades are moving slower than they used to even on a full charge — is the new battery the problem?

Reduced blade speed on a full charge is usually a cell capacity mismatch inside the pack, where one cell is weaker and drags the others down before the gauge registers low. We've seen this in 2-cell 7.4V packs where the replacement wasn't cycled properly out of the box — Li-ion cells need two or three full charge-discharge cycles to reach rated capacity. It can also be a contact resistance issue: corrosion or debris on the trimmer's battery terminals raises resistance and drops delivered voltage to the motor. Clean the contacts on both the battery and the trimmer with a dry cloth, do two full cycles, and recheck blade speed before assuming the pack is faulty.

I left the BS 80 battery sitting in the shed all winter and now the charger won't recognise it — how do I recover it?

Li-ion cells left in storage at low charge over several months can drop below the voltage threshold the charger uses to confirm a valid pack — typically around 5.5V for a 2-cell 7.4V configuration — and the charger simply refuses to engage. This isn't always a dead pack; it's a protection circuit lockout. Some chargers have a recovery or "boost" mode that applies a trickle current to bring the cells back above the recognition threshold — check your charger's manual for that function. If your charger has no recovery mode, measure the battery terminals with a multimeter; anything above 5V means the cells are likely recoverable with a compatible charger that supports pre-charge conditioning.