Accu45 3.6V Gardena Lawn Edge Trimmer Replacement Battery

My Gardena grass edger cuts fine for a bit then suddenly stops mid-row — is the battery dying or is something else going on?

That sudden cutoff is almost always the Ni-MH pack hitting its thermal protection threshold, not a dead cell — small 3.6V Ni-MH batteries in light garden tools drop voltage fast under sustained blade load, and the tool's protection circuit reads that sag as a fault and shuts down. Let the battery cool for ten minutes, then retry; if it completes a full edge run after cooling, the cells are weak but not dead — they're losing capacity and can't sustain current under continuous use. If it shuts off again just as quickly even when cool, the pack has likely developed a memory effect from repeated shallow charges, which is a known failure mode in this Ni-MH chemistry. Charge the replacement fully before first use and run it down completely for the first two cycles to set the capacity baseline correctly.

I just put the new Accu45 battery in my Rasenkantenschere 8800 and it won't turn on at all — charged it overnight and still nothing.

A fully charged Ni-MH pack that shows no response at all usually means the tool's contact pins aren't seating properly against the battery terminals — the Accu45 slides into a proprietary cradle and the contacts are small, so even a slight misalignment or debris in the slot breaks the circuit completely. Remove the battery, clean both the tool contacts and the battery terminals with a dry cloth, reseat it firmly until you hear or feel it click, then test again. If the tool still won't respond, check whether the charger actually brought the pack up: a resting Ni-MH at 3.6V nominal should measure around 4.1–4.3V fully charged with a multimeter across the terminals. If it's reading below 3.8V after an overnight charge, the charger isn't recognising the new pack — try a five-minute partial charge first to prime it, which resolves the "zero-volt detection" lockout some Gardena chargers trigger on new or deeply discharged packs.

My edger blade is spinning noticeably slower than it used to even right after charging — why does a new-looking battery lose power this fast?

Ni-MH cells in this voltage and size class are particularly vulnerable to shallow cycling — if the battery was regularly topped up before it was fully discharged, it builds voltage depression across the cells, and the pack delivers lower sustained voltage even when nominally "full." The edger blade speed is directly tied to pack voltage under load, so a battery running at 3.2V under load instead of the expected 3.4–3.5V will spin measurably slower. We found on the bench that replacement Ni-MH packs in this capacity class often need two to three full discharge-charge cycles before they reach rated output voltage under real load. Run the new pack down completely in the garden until the tool slows and stops, charge it fully, and repeat — blade speed should normalise by the third cycle.