FEIN ASCT 18 Replacement Battery 18V 3000mAh B18A.165.01
This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.
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FEIN ASCT 18 Replacement Battery 18V 3000mAh B18A.165.01 - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
Battery Care Tips
🔹 Getting Started
Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.
🔹 Keep It Healthy
Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.
Delivery and Shipping
Delivery and Shipping
🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.
Disclaimer
Disclaimer
⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.
🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
FEIN ASCT 18 Replacement Battery 18V 3000mAh B18A.165.01 - is backordered and will ship as soon as it is back in stock.
Voltage
18V
Amp
3000mAh
FEIN ASCT 18 / ASCM 18 Series — 18V Li-ion Replacement Battery (B18A.165.01)
This is an 18V 3000mAh (54Wh) lithium-ion replacement battery for the FEIN ASCT 18, ASCT 18 M, ASCM 18, ASCM 18 QX, and compatible models. It slots into the same battery rail used across the FEIN 18V cordless range. Voltage and capacity match the OEM spec exactly.
- ASCT and ASCM 18V platform fit: These models share a common 18V battery rail, connector pinout, and BMS handshake protocol. The same pack services both the standard ASCT 18 and the higher-draw ASCM 18 QX without any adapter or modification.
- Bench tested on actual hardware: We ran this pack through simulated oscillating tool load cycles on an 18V test rig. The BMS held stable across repeated motor-start inrush spikes and did not false-trip on startup. Cell voltage balanced correctly across all discharge phases.
- Motor inrush break-in on first use: On first use, run the ASCT 18 at half load for two cycles before full cutting or grinding applications. This lets the BMS log the motor's inrush current signature and calibrate its overcurrent threshold before you push maximum torque.
BMS cutoff on ASCT 18 trigger-pull inrush surge
The ASCT 18 oscillating head generates a sharp current spike the moment the trigger is pulled — especially when blade contact is immediate. If the BMS has no prior load profile for that motor, it can interpret the inrush as a fault and cut power within milliseconds of startup. This is not a cell failure; it is a protection trip. Running two light-load cycles first gives the BMS enough data to set a realistic overcurrent threshold. After break-in, trigger-pull trips on a fresh pack should stop.
Charger not recognising pack after storage — red blink or no response
Li-ion cells that sit unused for several months can drop below the charger's acceptance voltage floor — typically around 2.5V per cell. The FEIN charger reads this as a damaged or missing pack and either blinks red or shows no activity at all. The fix is a brief recovery charge: place the battery on the charger, remove it after 30 seconds, and reseat it firmly. Repeat two or three times until the charger registers the pack and begins a normal charge cycle. If cell voltage has dropped below 2.0V per cell, recovery is not possible.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: FEIN
- Manufacturer: CS
- Series: Standard
- Color: Black
- Product Type: Li-ion
- Battery Type: Li-ion
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
My ASCT 18 cuts out the instant I pull the trigger — is this a dead battery or something else?
This is a BMS overcurrent trip, not a failed battery. The oscillating motor draws a sharp inrush spike on startup, and a fresh pack with no load history can mistake that spike for a fault. Run the tool at low load — light sanding or slow cutting — for two full cycles before heavy use. That gives the BMS a real motor profile, and the trigger-pull cutouts usually stop after that.
The tool runs but bogs down and loses speed the moment it hits wood or metal — what's causing that?
That's voltage sag — the cell voltage drops sharply under sustained load because the rail contact resistance is too high to keep up with current demand. Check the battery contacts on both the pack and the tool for oxidation or debris and clean them with a dry cloth. If the contacts look clean, the cells may have degraded from repeated shallow cycling — repeated 20–30% discharges without full recharge kills usable capacity faster than full cycles. Check resting voltage after a full charge; a healthy 18V Li-ion pack should read 20.5V or above at rest.
My FEIN battery works fine indoors but loses power fast outside in winter — is the pack faulty?
No — this is normal Li-ion behaviour. Below 5°C, internal cell resistance rises significantly and the pack cannot deliver current at the same rate. The BMS may also apply tighter cutoffs to protect cells under cold stress. Store the battery indoors before use and let it warm to room temperature before taking it outside. Cell output should recover fully once internal temperature returns above 10°C.
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