Kingston MLW221 Replacement Battery 3.7V 1500mAh Li-ion
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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Kingston MLW221 Replacement Battery 3.7V 1500mAh Li-ion - 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.
Kingston MLW221 Replacement Battery 3.7V 1500mAh Li-ion - is backordered and will ship as soon as it is back in stock.
Voltage
3.7V
Amp
1500mAh
Kingston MLW221 — 3.7V Li-ion Replacement Battery (WMTM-169)
This is a 3.7V, 1500mAh Li-ion replacement battery for the Kingston MLW221 digital storage device. It fits the MLW221 directly, using OEM part number WMTM-169 as the compatibility reference. Install it when the original cell has degraded and the device no longer holds a usable charge.
- MLW221 platform fit: The MLW221 uses a compact single-cell Li-ion configuration at 3.7V nominal. This cell matches that voltage rail and the physical footprint — 50.20 × 51.30 × 5.50mm — so the connector seats correctly and the storage management system sees a valid cell on startup.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the MLW221 platform and confirmed the BMS accepted the cell without a fault code. Capacity read-back stabilised after a full calibration cycle rather than the first charge.
- MLW221 calibration cycle after install: The MLW221 storage management system estimates remaining capacity based on learned cell behaviour. After fitting a new cell, run the device down to low charge and then charge it fully in one uninterrupted session — this lets the firmware anchor its capacity estimate to the new cell's actual range.
Storage battery not accepted by the MLW221 after installation
The MLW221 storage management system validates the new cell during the first few charge cycles, not immediately on insertion. If the device shows a battery fault or refuses to complete a charge shortly after install, this is the firmware re-initialising against an unfamiliar cell profile. Give the system up to 24 hours of normal use and at least one full charge cycle. If the fault clears, the cell has been accepted — no hardware fault exists.
MLW221 showing lower capacity than 1500mAh after replacement
A new cell installed into the MLW221 does not automatically update the firmware's stored capacity estimate — the old cell's degraded profile may still be active. The device reports what it learned from the previous cell until a calibration cycle overwrites it. Discharge the device until it shuts off on its own, then charge uninterrupted to 4.2V full. After that single cycle, the capacity estimate displayed should align with the 1500mAh rating.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Kingston
- 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 Kingston MLW221 won't accept the new battery — it just shows a battery error on startup. What's wrong?
The MLW221's storage management firmware needs time to validate a new cell — this error on first boot is normal, not a sign of a faulty battery. The system re-initialises against the new cell profile over the first charge cycle, and in some cases takes up to 24 hours of use to clear the fault flag. Leave the device powered and connected to charge for a full uninterrupted session. If the error clears after that cycle, the battery has been accepted successfully.
The MLW221 is reporting only about half the expected capacity after I put in the new battery — is the cell faulty?
The capacity display on the MLW221 is based on the firmware's stored estimate from the old, degraded cell — it doesn't reset automatically on battery swap. The new 1500mAh cell is almost certainly fine, but the system needs one full calibration cycle to learn it. Run the device down until it powers off, then charge it fully to 4.2V in a single uninterrupted session. The capacity estimate should update to reflect the new cell's actual range after that cycle.
The Kingston MLW221 powers on fine but the battery drains noticeably faster than it did when the device was new — what causes that in storage batteries like this one?
Storage device batteries degrade through shallow cycling — repeated partial charges without a full discharge cycle cause the firmware's capacity window to compress over time, making the battery appear to drain faster than it actually does. This isn't a cell failure; it's a calibration drift in the storage management system. Force a full discharge-to-shutoff followed by a complete charge cycle to re-anchor the firmware's range. If the behaviour persists after two full cycles, the original cell has genuinely lost capacity and replacement is the correct fix.
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