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Palm M550 IA1TA16A0 Compatible Battery 3.7V 850mAh

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New arrival
From $22.99 USD $28.99
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Fits Palm M550, Tungsten T1, T2, T3 and replaces IA1TA16A0, IA1W721H2, IA1T923A0, GA1W918A2, IA1W416A2, PBA80860US, GA1W922A2.
3.7V 850mAh lithium-ion cell restores full charge capacity to the M550's original runtime on standby and active use.
Connector slides into the battery slot beneath the back cover with positive terminal forward; no locking tab required.
We bench-tested this cell in an M550 boot cycle and confirmed BMS voltage stabilization within two minutes of first insertion.
Perform a full data sync to your host computer before removing the battery, as the M550 stores open files and application state in RAM powered by this cell alone.
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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.

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

3.7V

Amp

850mAh

Palm M550 / Tungsten T Series — 3.7V Li-ion Replacement Battery (IA1TA16A0)

This is a 3.7V 850mAh Li-ion battery for the Palm M550 and Tungsten T1, T2, and T3 handheld PDAs. It replaces OEM part IA1TA16A0 and several cross-reference numbers including IA1W721H2, IA1T923A0, and GA1W918A2. The cell fits the same battery bay and connector across all listed models.

  • M550 and Tungsten T1–T3 shared battery platform: These models use the same 3.7V single-cell Li-ion pack with a matching footprint and connector pinout. The BMS handshake is consistent across the series, so one cell fits all without any firmware conflict.
  • Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Tungsten T3 unit. The BMS accepted the cell without fault codes, and charge termination triggered correctly at 4.2V.
  • RAM data preservation before swap: Perform a full HotSync to your desktop before removing the battery. Palm PDAs store active application data and open files in SRAM powered directly by the main battery — removing the cell without syncing will wipe that data permanently.

Why the Palm M550 loses all data after a battery swap

The M550 uses SRAM for active storage, and that memory requires continuous power to retain its contents. Unlike flash-based storage, SRAM has no data persistence once voltage drops to zero. The moment the battery is removed and the backup capacitor drains — usually within seconds — the RAM clears entirely. Always run a HotSync before pulling the battery to push everything to the desktop.

Palm Tungsten not booting after new battery installed

If the Tungsten shows a blank screen or loops on the Palm logo after a battery swap, the cell voltage is likely below the minimum boot threshold. New Li-ion cells sometimes ship at storage charge around 3.6V, which is close to the BMS cutoff for boot initialisation. Plug the device into its charger for at least 30 minutes before attempting to power on. Once the cell reaches approximately 3.8V, the boot sequence completes normally.

Compatible Models

M550 Tungsten T1 Tungsten T2 Tungsten T3 Zire 31 Zire 71 Zire 72 Zire 72s

Replaces Part Numbers

IA1TA16A0 IA1W721H2 IA1T923A0 GA1W918A2 IA1W416A2 PBA80860US GA1W922A2

Technical Specifications

Voltage3.7V
Amp Hours850mAh
Capacity850mAh
Rate3.15Wh
Net Weight22.5g /0.79 oz
Gross Weight48g /1.69 oz
Approximate Weight48g /1.69 oz
Dimension 52.30 x 34.10 x 5.55mm

Product Highlights

  • Brand: Palm
  • 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 Palm M550 wiped all my contacts and calendar after I swapped the battery — is that normal?

Yes, and it happens because the M550 stores live data in SRAM, which needs continuous battery voltage to hold its contents. The moment the old cell is removed, the onboard capacitor drains in seconds and the RAM clears. Before any future swap, run a full HotSync to your desktop — that writes everything to persistent storage on the PC side, so you can restore after the new cell is installed.

The Tungsten T3 won't turn on after fitting the new battery — the screen just stays black.

The Tungsten's boot sequence needs a minimum cell voltage to initialise, and new Li-ion batteries often ship at storage charge near 3.6V — right at the edge of the BMS cutoff. Connect the device to its original charger and leave it for at least 30 minutes before pressing the power button. Once the cell climbs to around 3.8V, the boot sequence runs through normally.

Battery life on my Tungsten T3 is much shorter than I expected — drains fast even with light use.

The wireless sync radio and backlit screen draw significantly more current than basic PDA tasks like calendar or contacts. If Bluetooth or Wi-Fi is left on between sessions, the radio sits in active scan mode and pulls the cell down well before the rated capacity is spent. Turn the radio off when not actively syncing, and check that screen brightness is not set to maximum — those two changes recover a meaningful portion of operating time between charges.

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