3.7V Einhell 6 Li Grass Shear Compatible Battery 2900mAh

Einhell Cordless Grass and Shrub Shear — 3.7V Li-ion Replacement Battery

This 3.7V 2900mAh Li-ion cell replaces the factory battery in Einhell cordless grass and shrub shears, including the 6 LI, 6/1 LI, and RCG 3 series. These shears run a compact single-cell platform — getting the voltage and physical format right matters, and this cell matches both. Capacity sits at 2900mAh, which is a step up from most OEM packs on this platform.

• Shared platform compatibility: The 6 LI, 6/1 LI, and Akku-Gras- und Strauchschere models share the same 3.7V single-cell architecture and connector format, so one battery spec covers the range.
• Bench tested on actual hardware: We ran full charge and discharge cycles — the BMS held voltage steady under cutting load and tripped cleanly at the low-voltage cutoff without forcing a hard shutdown.
• First charge on a new cell: Run a full charge before first use on a Li-ion cell that's been in storage — it lets the BMS calibrate the state-of-charge range and avoids a false low-battery cutoff mid-job.

Why cell dimensions matter on compact shear batteries

Einhell's grass shear battery compartment is tight — it's sized to a specific cylindrical cell format. This replacement measures 66.65 x 19.50 x 18.50mm, matching the OEM footprint. A cell even a few millimetres out of spec won't seat correctly against the contact plate, which causes intermittent power loss during cutting.

Shear cuts out suddenly mid-use — here's what's happening

On aged or degraded cells, internal resistance climbs. Under the brief current spikes that happen when blades hit thick grass stems, voltage sags past the BMS cutoff threshold and the tool shuts off — even with charge remaining. Replacing the cell restores headroom above that cutoff. If the new battery shows the same behaviour, check the blade contact points for debris buildup causing mechanical drag.