About this replacement
AL-KO Cordless Gardening Tool — 18V Li-ion Replacement Battery
This 18V 3000mAh Li-ion pack replaces the original battery across AL-KO's Comfort series cordless garden tools, including the GT 1825, PS 181, HTA 1845, and PS 1815 among others. At 54Wh, it matches the factory voltage rail these tools draw from. Dimensions are 116 x 80.3 x 65mm — same footprint as the OEM unit.
- Comfort series compatibility: These 30+ models share the same 18V platform and battery connector, so one pack covers the full range without adapter or modification.
- Bench tested on actual hardware: We ran full charge/discharge cycles — the BMS held voltage steady under load and tripped the low-voltage cutoff cleanly before cell damage could occur.
- First charge before use: With Li-ion packs that have sat in storage, run a full charge before the first session — this lets the BMS calibrate state-of-charge accurately from the start.
What the BMS does under load
The battery management system monitors cell temperature, current draw, and voltage in real time. If current spikes — during heavy cutting or thick material — the BMS throttles output before cells are stressed. That protection matters more on garden tools than many users expect, because motors stall and surge repeatedly during normal use.
Tool powers on, then cuts out immediately — here's why
This usually means the BMS is reading the pack as depleted even after a full charge. It happens when cells have drifted out of balance after long storage. The fix is to leave the pack on the charger for a full uninterrupted cycle, then discharge it completely through normal use before charging again. One or two full cycles typically resets the balance and clears the fault.