About this replacement
Gardena Cordless Grass Shears — 7.2V Ni-MH Replacement Battery
This listing is for a 7.2V 3000mAh Ni-MH replacement battery for the Gardena Rasenschere and Gartenschere cordless grass shears. It fits the Accu90 battery platform used in models 8804 and 8820 — handheld cutting tools used for trimming grass edges and small hedges. Capacity is 3000mAh (21.6Wh), matching the original specification.
- Accu90 platform compatibility (8804, 8820): Both models share the same 7.2V Accu90 battery rail, connector format, and BMS communication — one battery serves both without modification.
- Bench tested on actual hardware: We ran full charge/discharge cycles — the BMS held voltage steady under cutting load and tripped cleanly at the low-voltage cutoff without over-discharging the cells.
- First charge on Ni-MH: Run the battery through two to three full charge/discharge cycles before regular use — Ni-MH cells reach rated capacity only after conditioning, not straight out of the box.
Why Ni-MH chemistry suits low-voltage grass shears
At 7.2V, Ni-MH cells deliver a flat discharge curve that keeps motor torque consistent through most of the charge cycle. This matters for shears — blade speed stays even rather than dropping off early. Ni-MH also tolerates the short, interrupted duty cycles typical of edge trimming without the stress that Li-ion cells can accumulate from repeated shallow pulls.
Shears losing power mid-task — what's causing it and how to fix it
If the shears slow noticeably before the battery indicator shows low charge, the cells have likely developed voltage depression from repeated partial charges — a known Ni-MH issue. The fix is a deliberate full discharge followed by a slow full charge, repeated two to three times. This resets cell balance across the pack and restores usable capacity. Avoid storing the pack in a partially charged state for extended periods, as this accelerates the problem.