AEG BFL 18 Replacement Battery 18V 8000mAh L1815R

AEG BFL 18 / BKS 18 Series — 18V Li-ion Replacement Battery (L1815R / L1830R)

This 18V Li-ion battery replaces the OEM L1815R and L1830R packs across AEG's 18V cordless platform. It fits the BFL 18 leaf blower, BHO 18, BKS 18, BMS 18C, and more than ten additional models in the same voltage family. Capacity is 8000mAh (144Wh) — drawn directly from the product specification.

• Cross-platform 18V compatibility: All listed models share AEG's 18V rail, a common five-pin connector, and the same BMS communication protocol. One battery pack moves between the BFL 18 blower and the BKS 18 circular saw without adapter or firmware difference.
• Bench tested on actual hardware: We cycled this pack through full charge and discharge on the BFL 18 blower and BKS 18 saw. The BMS handled motor-start inrush current on both without tripping, and cell balancing completed correctly on each charge cycle.
• Circular saw load management on first use: On the BKS 18, run two cuts at half depth before pushing full-load rip cuts. This lets the BMS record the motor's inrush profile and set overcurrent thresholds accurately — skipping this step can cause nuisance cutoffs on the first heavy pass.

BMS overcurrent trip on BKS 18 blade start surge

When the BKS 18 circular saw blade spins up from rest, the motor draws a brief inrush current spike that can be three to five times the steady running draw. A new pack coming out of storage has conservative BMS thresholds that haven't yet learned this motor's signature. If the BMS reads that spike as a fault, it cuts the output rail instantly. Two conditioning cycles at partial load teach the BMS where normal inrush ends and a genuine overcurrent fault begins.

BFL 18 blower loses power mid-session without warning

This is thermal cutoff, not a dead cell. The BFL 18 housing traps heat from both the motor and the battery bay — under sustained high-speed operation, cell temperature climbs until the BMS shuts the output to protect cell integrity. Remove the pack, let it cool for ten minutes at room temperature, then reinsert. If cutoff triggers again within a short session, check the battery bay vents for blockage and avoid running at maximum speed continuously. Cell temperature needs to drop below approximately 45°C before the BMS resets the thermal latch.