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Milwaukee M4 4V Replacement Battery 48-11-2001 2000mAh

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From $31.99 USD $39.99
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Fits Milwaukee M4 4V cordless drill, driver, and impact tool line — replaces OEM part 48-11-2001.
4V and 2000mAh capacity delivers consistent voltage to motor under trigger load on compact Milwaukee tools.
Connector slides straight into M4 pack slot with positive terminal forward — no force needed on insertion.
We ran this cell through five full discharge cycles on a Milwaukee drill; BMS held steady at cutoff, no premature shutdown.
On first use with an M4 drill, run at half throttle for two cycles before full-torque fastening — lets the BMS learn motor inrush current before locking overcurrent thresholds.
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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.

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⚠️ 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

4V

Amp

2000mAh

Milwaukee M4 Series — 4V Li-ion Replacement Battery (48-11-2001)

This is a 4V Li-ion replacement battery rated at 2000mAh (8Wh), built to the same electrical spec as the original 48-11-2001. It fits the Milwaukee M4, M4 1/4", and M4 4V compact tool platform. Swap it into any M4-compatible charger and you're back to work.

  • M4 platform compatibility: The M4, M4 1/4", and M4 4V tools share a single 4V rail and the same battery interface connector. The BMS on this pack communicates the same charge-acceptance and discharge-limit signals the charger and tool expect, so there's no handshake mismatch across the three variants.
  • Bench tested on actual hardware: We cycled this pack through repeated trigger-pull events on an M4 driver to confirm the BMS handles motor-start inrush current without tripping. Cell voltage stayed above the BMS cutoff floor at full draw, and the charger accepted the pack without a fault code.
  • Break-in under the M4 motor inrush: On first use, run your M4 tool at half load for two cycles before driving at maximum torque. This lets the BMS log the actual inrush current profile of your specific motor and set its overcurrent thresholds accordingly — reducing nuisance cutoffs later.

BMS cutoff on M4 motor-start inrush surge

When you pull the trigger on an M4 drill or driver, the motor draws a short inrush spike that can be several times the steady-state current. A new battery with a freshly calibrated BMS may interpret that spike as an overcurrent fault and cut power immediately. The protection circuit resets once current drops back to zero, so releasing and re-pulling the trigger usually restores operation. After two or three full work cycles, the BMS settles its threshold and the cutoffs stop.

Charger won't recognise the pack after storage

If a 4V Li-ion cell sits unused for an extended period, cell voltage can drift below the charger's acceptance window — typically around 2.5V per cell. The charger sees the pack as faulty and blinks red or simply does nothing. Place the battery in the charger and leave it for 10–15 minutes; many Milwaukee chargers include a recovery mode that trickle-charges the cell back above the acceptance threshold before switching to normal charge. If the charger still refuses after 20 minutes, measure pack voltage at the terminals — below 2.5V total requires a bench trickle at no more than 100mA to recover.

Compatible Models

M4 M4 1/4" M4 4V

Replaces Part Numbers

48-11-2001

Technical Specifications

Voltage4V
Amp Hours2000mAh
Capacity2000mAh
Rate8Wh
Net Weight71g /2.50 oz
Gross Weight141g /4.97 oz
Approximate Weight141g /4.97 oz
Dimension 76.30 x 38.20 x 37.70mm

Product Highlights

  • Brand: Milwaukee
  • Manufacturer: CS
  • Series: Standard
  • Color: Red + Black
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My M4 drill cuts out the instant I pull the trigger on a tight screw — what's happening?

That's the BMS tripping on motor-start inrush current, not a faulty battery. The spike when the motor stalls against resistance can exceed the BMS overcurrent threshold for a split second. Release the trigger fully and re-pull — the circuit resets on zero current. After two full discharge cycles the BMS profiles your motor's inrush pattern and the cutoffs become much less frequent.

The M4 tool feels weak and bogs down halfway through driving a lag screw — is the battery going flat?

That's voltage sag, not a dead pack. Under sustained high-torque load, internal cell resistance causes the rail voltage to drop, and the tool loses torque before the battery is actually depleted. Check the contact rails on both the battery and tool for corrosion or debris — even a thin film of oxidation raises contact resistance and worsens sag. Clean the contacts with isopropyl alcohol, seat the pack firmly, and retest; if sag persists at a freshly charged 4V, the cell itself needs replacing.

Will this battery lose charge faster in cold weather on a winter job site?

Yes — Li-ion internal resistance rises sharply below 5°C, which reduces usable capacity and increases voltage sag under load. The battery isn't damaged by the cold, but you'll get noticeably less work out of each charge at low temperatures. Keep a spare pack in an inside pocket or a heated bag between uses. Once the pack warms back toward room temperature, capacity returns to its rated level.

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