Wolf Garten Vario RV-E8 4.8V Replacement Battery 3600mAh

My Wolf Garten grass shears cut fine for a minute then the blades slow down and barely move — is the battery dying or is something else wrong?

On Ni-MH cells at this voltage, blade slowdown mid-cut usually means the pack is voltage-sagging under load rather than being fully dead — the resting charge looks fine but collapses the moment the motor draws current. This happens when individual cells in the pack have drifted out of balance after many shallow charge cycles, which is extremely common in seasonal garden tools that get topped up after every short session. Before replacing anything, fully discharge the shears until they stop, then do a full uninterrupted charge — if the problem returns within the first few cuts, the pack can no longer hold voltage under load and needs replacing. Check the blade mechanism for grass build-up too, since extra resistance accelerates the sag.

I charged the RV-E8 overnight and the shears feel warm but the blades have almost no power — did I overcharge it?

Ni-MH cells at 4.8V are vulnerable to heat damage from extended uncontrolled charging, and warmth after a long charge with weak output is a classic sign of a pack that has been pushed into a partially reversed cell state. One cell in the five-cell series string reverting polarity drags the whole pack's usable voltage down while still generating heat. This isn't recoverable through further charging. Check the pack voltage with a multimeter — a healthy fully-charged 4.8V Ni-MH pack should read between 5.5V and 6.0V; anything below 5.0V after a full charge confirms cell damage.

The Wolf Garten Vario battery sat in the shed all winter and now the charger won't recognise it — how do I get it to take a charge again?

Ni-MH packs that self-discharge over a long storage period can drop low enough that the charger's detection circuit refuses to start a charge cycle, treating the pack as faulty. This is a known recovery situation, not necessarily a dead battery. Try briefly connecting the pack to the charger for 30-second intervals repeatedly — some chargers will eventually detect enough residual voltage to begin a trickle charge that brings it back into normal range. Measure the pack voltage first: if it reads below 3.5V, the cells have likely self-discharged into a deep discharge state and recovery is unlikely without a bench charger capable of a manual trickle-start.