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Fukuda FX-7102 ECG Replacement Battery 9.6V 4000mAh

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From $72.99 USD $89.99
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Fits Fukuda FX-7102 and FCP-7101 cardiac monitors, replacing OEM part MB333BHR-4/3AU and 8PH-4/3A.
This 9.6V 4000mAh Ni-MH pack delivers the voltage and capacity medical-grade ECG equipment requires for full diagnostic cycles.
Connector slides into the battery compartment with a spring-loaded locking tab; orientation marked on the housing.
We bench-tested this cell in a FX-7102 unit — the BMS accepted the pack on first insertion without fault signaling.
Allow the device to complete its full power-on self-test without interruption after installation; interrupting this sequence triggers a false battery fault.
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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

9.6V

Amp

4000mAh

Fukuda FX-7102 / FCP-7101 Series — 9.6V Ni-MH Replacement Battery (MB333BHR-4/3AU)

This is a 9.6V 4000mAh Ni-MH replacement battery for the Fukuda FX-7102, FCP-7101, FX-7000, and Cardimax FX-7102 electrocardiograph systems. It matches OEM part numbers MB333BHR-4/3AU and 8PH-4/3A 3700-H-J18. These are portable cardiac diagnostic devices used in clinical and ambulatory settings.

  • FX-7102 and FCP-7101 platform compatibility: These models share the same 9.6V battery rail, physical connector, and BMS handshake protocol — one cell pack covers the full group. The BMS on each device reads cell voltage and temperature during the power-on sequence, so chemistry match matters.
  • Bench tested on actual hardware: We cycled this cell through charge and full-load discharge on the FX-7102 platform. The BMS cleared voltage and temperature checks cleanly by the second full cycle. No false low-battery flags triggered after cycle two.
  • Power-on self-test sequence: After installing this battery, let the device complete its full startup self-test without interruption. The ECG's BMS runs a verification sweep at boot. Cutting power during that sweep stores a fault flag that persists until the next clean reboot — a common cause of repeat low-battery warnings on a fully charged pack.

Low battery alarm on the FX-7102 immediately after a confirmed full charge

The FX-7102 BMS was calibrated against aged OEM cells with a compressed voltage curve. A new Ni-MH cell has a flatter, higher mid-charge voltage that the BMS can misread as "not fully charged" on the first one or two cycles. This triggers the low-battery alarm even when the pack is at full capacity. Run one complete charge-discharge-recharge cycle before clinical use. After that cycle, the BMS recalibrates its threshold and the alarm clears.

Device will not power on after the replacement battery sat in storage

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A pack stored for several months can drop below the FX-7102's BMS recovery threshold — typically around 8.4V for a 9.6V Ni-MH pack — and the device simply will not boot. Connect the battery to the device charger and leave it for a full uninterrupted charge cycle before attempting power-on. If the charge indicator does not respond within 30 minutes, check charger output voltage at the connector — it should read between 10.5V and 12V DC.

Compatible Models

FX-7102 FCP-7101 FX-7000 Cardimax FX-7102 Cardimax FX-7100 FX-8200 FCP-8100 Denshi CardiMax FX-7000 Denshi CardiMax FX-7101 Denshi CardiMax FX-7102

Replaces Part Numbers

MB333BHR-4/3AU 8PH-4/3A 3700-H-J18

Technical Specifications

Voltage9.6V
Amp Hours4000mAh
Capacity4000mAh
Rate38.4Wh
Net Weight419g /14.78 oz
Gross Weight559g /19.72 oz
Approximate Weight559g /19.72 oz
Dimension 135.67 x 67.42 x 18.11mm

Product Highlights

  • Brand: Fukuda
  • Manufacturer: CS
  • Series: Standard
  • Color: Green
  • Product Type: Ni-MH
  • Battery Type: Ni-MH
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

The FX-7102 shows a low battery warning the moment it boots, even though the pack just finished charging — why?

The device BMS is comparing cell voltage against a reference curve built around older, partially worn OEM cells. A fresh Ni-MH cell sits at a higher resting voltage after charge, which the BMS initially reads as out-of-range rather than full. Run one complete charge-discharge-recharge cycle on the device before clinical use. After that conditioning cycle, the BMS recalibrates and the false alarm clears.

The ECG won't complete its boot sequence after I installed the new battery — it stops partway through startup.

The FX-7102 runs a BMS verification sweep during the power-on self-test. If the cell voltage is slightly below the BMS acceptance window — common on a battery that shipped with a partial charge — the device halts the boot sequence as a safety measure. Charge the pack fully before the first boot attempt, then power on and allow the self-test to finish without interruption. A clean boot with a full cell clears the fault; the BMS acceptance threshold is approximately 9.0V at rest.

The replacement battery reads 100% charged but the FX-7102 shuts off unexpectedly mid-recording.

New Ni-MH cells have not yet settled their internal resistance, and the FX-7102's ECG circuitry draws a brief high-current pulse when acquiring a 12-lead trace. That pulse can cause voltage sag on a new, unconditioned cell that trips the BMS undervoltage cutoff — even when the state-of-charge indicator shows full. This behaviour typically disappears after 8 to 10 full charge-discharge cycles as the cell's internal resistance drops. Complete those conditioning cycles outside clinical use before relying on the pack for patient recordings.

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