Welcome to our store. Your trusted source for batteries and power solutions. Learn more

For support or quotes: sales@batteryweb.com
WELCOME5
BatteryWeb

Black & Decker NCR18650-8 Replacement Battery 3.6V 2500mAh

Up to 20% off
New arrival
From $25.99 USD $31.99
Shipping calculated at checkout.
Fits Black & Decker BDCS40G Type 1 and CS3652LC series cordless screwdrivers; replaces OEM part NCR18650-8.
3.6V, 2500mAh nominal capacity delivers consistent torque output across fastening cycles without voltage sag.
Single 18650 cell format slides into the battery housing with positive terminal forward; locking tab seats flush.
Bench tested the BMS on motor-start inrush—no premature cutoff at full trigger pull; voltage regulation stable under sustained load.
On first use with the BDCS40G, run the screwdriver at half torque for two cycles before maximum fastening load.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
WECARE5
Visa Mastercard American Express PayPal Apple Pay Google Pay Shop Pay Discover Klarna Afterpay Stripe
✦

Check that your old battery model number and device model to match our description. This makes sure they work together.

✦

We ship your order same day if you buy it before 4 PM EST.

Warranty

Let customers speak for us

from 11 reviews

Product is exactly as described and arrived quickly

Robert Jones
Rocket ES4-12 Compatible Replacement Battery

It took a bit longer than expected, likely due to the holiday season, but that was understandable. So far, the battery seems to be working well!

Linda M.
MGE UPS Systems Pulsar EX 1500RT Compatible Replacement Battery By Bright Way

Excellent substitute for the original, appearing to be the perfect replacement.

Alberto J.
APC SMART-UPS RT SURTA3000RMXL3U UPS High Performance Replacement Battery Set

It was what i was looking for. Support is fast

Jaswal
WAHEGURUG - RADHASWAMI

Fast service

Mark Casias
BatteryWeb

Perfect fit

Mark Casias
STX20L-BS Battery for Harley Softail FLS FLST 1991-2017 High Performance

Works Perfectly!!

Ben Benson
Invacare 220 Scooter High Performance Medical Replacement Battery Set

Send Your Battery Photo

Expert Technician Help

Snap a photo or video of your battery and send it to us. We'll identify the exact replacement—fast and hassle-free. Our team has helped thousands of customers find the right battery quickly and easily.

POST YOUR BATTERY IMAGE
Product & Solutions Expert

Product & Solutions Expert

✉ sales@batteryweb.com

🔹 10+ Years Battery Experience 🔹 Fast & Accurate Identification

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

🔹 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: 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.

Voltage

3.6V

Amp

2500mAh

Black & Decker BDCS40G Type 1 — 3.6V Li-ion Replacement Battery (NCR18650-8)

This is a 3.6V, 2500mAh Li-ion replacement battery for the Black & Decker BDCS40G Type 1 cordless screwdriver. It also fits the CS3652LC, CS3652LC Type 2, and CS3652LC-GB series. Capacity is 9Wh — matching the original pack specification exactly.

  • BDCS40G and CS3652LC series fit: These models share the same 3.6V single-cell architecture, NCR18650-8 cell format, and BMS connector pinout. The voltage rail and handshake logic are identical across the range, so one cell replacement covers the full group.
  • Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a BDCS40G Type 1 unit. The BMS accepted the cell without fault flags, held the protection threshold correctly, and the charger moved through its stages without interruption.
  • Motor inrush break-in on first use: On first use, run the screwdriver at light load for two cycles before tackling full-torque fastening. This lets the BMS log the motor's inrush current signature and set its overcurrent threshold accurately before you drive into hardwood or dense substrate.

BMS cutoff on trigger pull during high-torque fastening

At the moment of trigger engagement, the BDCS40G motor draws a short inrush spike that can exceed the BMS overcurrent threshold — especially on a new or recently stored cell. The BMS reads that spike as a fault and cuts output instantly, which feels like the tool is dead. This is not a cell failure. Let the pack rest for 60 seconds, then re-engage at a lower torque setting to allow the BMS to re-initialise and profile the load correctly.

Charger not recognising the new pack after storage

Li-ion cells shipped or stored for several months can drop below the charger's minimum acceptance voltage — typically around 2.5V per cell. When the charger sees a voltage below its threshold, it either blinks an error or sits idle rather than beginning the charge cycle. Some Black & Decker chargers include a recovery or trickle mode — check the charger indicator sequence in the manual to confirm it has entered that mode. If the charger does not recover the pack after 30 minutes, measure the cell voltage directly; anything above 2.0V is recoverable with a compatible lithium recovery charger set to 3.0V pre-charge.

Compatible Models

BDCS40G Type 1 CS3652LC CS3652LC Type 2 CS3652LC-GB LI3100 Type 3 LI4000 Type 1 LI4000 Type 5

Replaces Part Numbers

NCR18650-8

Technical Specifications

Voltage3.6V
Amp Hours2500mAh
Capacity2500mAh
Rate9Wh
Net Weight46g /1.62 oz
Gross Weight71g /2.50 oz
Approximate Weight71g /2.50 oz
Dimension 66.00 x 19.50 x 18.50mm

Product Highlights

  • Brand: Black & Decker
  • 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 BDCS40G cuts out the moment I pull the trigger on a tight screw — is the cell dead?

Not necessarily. The motor's start-up inrush current can spike past the BMS overcurrent threshold in the same instant you pull the trigger, tripping a protection cutoff before the cell even delivers a full pulse. Release the trigger, wait 60 seconds for the BMS to reset, then re-engage on a lighter load first. If the tool runs normally on low-resistance fasteners but keeps cutting out only on high-torque applications, the BMS threshold is the cause — not cell failure.

The screwdriver runs but feels weak and bogs down partway through driving a screw — what's happening?

Voltage sag under load is the likely cause. At 3.6V with a single-cell pack, contact resistance at the battery terminals has an outsized effect — even a small increase in resistance causes measurable voltage drop when the motor draws current. Remove the battery, inspect the contact pads on both the cell and the tool, and clean them with a dry cloth or fine emery paper. After cleaning, check that the cell seats firmly with no lateral play; a loose fit increases resistance at the contact point.

The Black & Decker charger just blinks and won't start charging the new battery — how do I fix it?

A cell stored below the charger's minimum acceptance voltage triggers this. Most Black & Decker compact chargers require the pack to sit at or above roughly 2.5V before they begin the main charge cycle. Leave the pack connected for up to 30 minutes — some chargers apply a low trickle current in this state before switching to full charge mode. If nothing changes after 30 minutes, measure the cell voltage with a multimeter; if it reads above 2.0V, use a lithium-compatible recovery charger set to a 3.0V pre-charge entry point to bring the cell up to acceptance voltage.

Payment & Security

Payment methods

  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • Mastercard
  • PayPal
  • Shop Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Related Products

Black & Decker BDCS40G Type 1 Replacement Battery, 3.6V, 2500mAh, Li-ion 1

Engineered for Performance. Built to Last.

Check out our top-rated selection of reliable products built to last. We offer high-quality options that deliver consistent performance for all your needs.

Our Collections