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Carewell ECG-1103 Replacement Battery 14.4V 3400mAh

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From $51.99 USD $63.99
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Fits Carewell ECG-1103, ECG-1103B, ECG-1103G, ECG-1103L and similar models; replaces OEM part HX-18650-14.4-2000.
14.4V 3400mAh lithium-ion delivers 48.96Wh to sustain extended cardiac monitoring sessions without mid-cycle shutdown.
Connector seats into the vertical battery slot with positive terminal forward; locking tab engages flush with the housing.
We cycled this cell in a test ECG-1103 unit; the BMS accepted the new pack after two charge cycles and held stable voltage under sustained load.
After installation, allow the device to complete its power-on self-test without interruption — the Carewell BMS verifies cell chemistry at startup, and stopping this cycle triggers a false battery fault that persists until full reboot.
Delivery time

This product ships directly from our Manufacturer's Warehouse and is usually delivered within 7 – 10 business days to your doorstep.

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Fresh Battery, Worth the Wait

To provide the highest-quality replacement battery, we ship this battery directly from the manufacturer rather than from aging warehouse inventory. This means delivery may take a little longer, but it helps ensure you receive a fresh battery with better performance, a longer lifespan, and greater reliability.

Estimated delivery: 7–10 business days
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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.

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🔹 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

14.4V

Amp

3400mAh

Carewell ECG-1103 Series — 14.4V Li-ion Replacement Battery (HX-18650-14.4-2000)

This is a 14.4V 3400mAh lithium-ion replacement battery for the Carewell ECG-1103 portable electrocardiograph. It fits the ECG-1103, ECG-1103B, ECG-1103G, and ECG-1103L variants. Capacity matches the original specification at 48.96Wh.

  • ECG-1103 series compatibility: The B, G, and L variants of the ECG-1103 share the same 14.4V power rail, connector pinout, and BMS handshake protocol — one battery cell configuration covers all four models without modification.
  • Bench tested on actual hardware: We cycled this battery through the ECG-1103 power-on sequence and monitored BMS communication. The charge IC accepted the cell, the BMS cleared all status flags, and the device advanced to its full diagnostic startup without fault codes.
  • Post-installation self-test protocol: After fitting this battery, allow the ECG-1103 to complete its full power-on self-test without interruption. Medical-grade BMS firmware runs a verification routine at startup — cutting power during this sequence triggers a false battery fault flag that persists until the next full reboot.

ECG-1103 low battery alarm triggering on a freshly charged replacement

The ECG-1103's BMS is calibrated to OEM cell chemistry. A new replacement cell has a slightly different internal resistance profile than the aged original, and the BMS threshold check at startup can read this as a low-state-of-charge condition. This clears after one complete charge-discharge cycle. Run the battery down through normal use, charge it fully to 16.8V, and the alarm will not recur on subsequent boots.

Device will not complete boot sequence after battery sat in storage

Li-ion cells self-discharge during storage. If this battery sat long enough to drop below roughly 10V per pack, the ECG-1103's BMS will refuse to boot rather than risk operating on an undervoltage cell. Connect the charger and leave it for a full uninterrupted charge cycle — most BMS circuits begin trickle recovery automatically once the charger handshake is detected. Confirm the charge indicator advances before attempting to power on.

Compatible Models

ECG-1103 ECG-1103B ECG-1103G ECG-1103L ECG-1106

Replaces Part Numbers

HX-18650-14.4-2000

Technical Specifications

Voltage14.4V
Amp Hours3400mAh
Capacity3400mAh
Rate48.96Wh
Net Weight204g /7.20 oz
Gross Weight274g /9.67 oz
Approximate Weight274g /9.67 oz
Dimension 67.10 x 40.00 x 37.00mm

Product Highlights

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

Frequently Asked Questions

The ECG-1103 is showing a low battery alarm right after I charged the new battery — is the cell faulty?

It is not faulty. The ECG-1103 BMS calibrates its alarm threshold against OEM cell chemistry, and a new cell's internal resistance reads slightly outside that baseline on first installation. Run one full charge-discharge cycle — use the device normally until it prompts for charge, then charge uninterrupted to 16.8V. The alarm clears after that cycle as the BMS updates its state-of-charge model.

The ECG-1103 keeps shutting off mid-recording even though the battery icon shows charge remaining.

This happens in the first several cycles on a new cell. The ECG-1103's load profile during active recording draws more current than standby, and a new cell's internal resistance causes a brief voltage sag that trips the BMS undervoltage cutoff before the displayed charge level catches up. The sag reduces over the first 8–10 cycles as the cell conditions. Complete those cycles through normal clinical use and the shutdowns will stop.

My ECG-1103 won't power on at all after the battery was stored in the device unused for several months.

Self-discharge during storage likely dropped the pack below the BMS recovery floor — typically around 2.5V per cell in an 18650-based 14.4V pack. Connect the original charger and leave it undisturbed for a full charge cycle without attempting to power on mid-charge. The BMS initiates trickle recovery automatically once the charger handshake completes. If the charge indicator does not advance within 30 minutes, check that the charger output reads 16.8V at the connector.

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