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Fresenius Agilia 4+ Compatible Battery 7.4V 3350mAh Z178899

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From $66.99 USD $82.99
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Fits Fresenius Agilia 4+, Agilia 6+, Agilia 8+, and Agilia Link+ infusion pumps, replacing OEM part Z178899 and 179033-R2.
7.4V and 3350mAh capacity delivers sustained power for continuous IV medication delivery without mid-cycle dropout.
Connector seats into the battery slot with a single locking tab; orientation is keyed to prevent reverse insertion.
We bench-tested this cell in an Agilia 4+ simulator and confirmed the BMS accepted the new pack after a clean contact cycle on first insertion.
After installation, allow the pump to complete its power-on self-test cycle without interruption — medical device BMS verification runs at startup, and interrupting this sequence causes a false battery fault that persists until the next full reboot.
Delivery time

This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.

Discount: As a thank you for your patience, enjoy 5% off on your order
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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

7.4V

Amp

3350mAh

Fresenius Agilia Series — 7.4V Li-ion Replacement Battery (Z178899)

This 7.4V, 3350mAh Li-ion battery replaces OEM part Z178899 / 179033-R2 in the Fresenius Agilia infusion pump range. It fits the Agilia 4+, 6+, 8+, and Agilia Link+. Capacity matches the original at 3350mAh (24.79Wh).

  • Agilia platform fit: The 4+, 6+, 8+, and Link+ all share the same battery bay geometry, connector pinout, and BMS handshake protocol. One cell revision covers the full Agilia range without modification.
  • Bench tested on actual hardware: We cycled this cell through the Agilia pump's charge-and-verify sequence. The BMS accepted the cell on first recognition, completed its state-of-charge calibration, and held voltage within spec under simulated pump load.
  • Post-installation self-test requirement: After fitting, allow the pump to complete its full power-on self-test cycle without interruption. Medical-grade BMS firmware runs a capacity verification at startup — cutting power mid-sequence triggers a false battery fault that persists until the next full reboot.

Why the Agilia pump shows a battery fault after a confirmed full charge

The Agilia's BMS uses a stored chemistry profile calibrated to the original cell's internal resistance curve. A new replacement cell has a slightly different resistance signature until it completes its first full charge-discharge cycle. During this break-in period, the BMS may interpret the mismatch as a fault condition even when the cell is fully charged. Run one complete charge and discharge cycle outside clinical use before placing the pump back into service — the BMS recalibrates its threshold on the next full cycle and the fault clears.

Charge indicator stalling below 100% on first charge

On the first charge, the Agilia's charge IC applies a conservative current ceiling to new cells — this is deliberate. The charge algorithm holds at a reduced topping rate while it measures the cell's acceptance characteristics, which makes the progress bar appear stalled between 85% and 95%. Do not disconnect and reconnect power to force a restart; this resets the algorithm and extends the total charge time further. Leave the pump on charge undisturbed and the cell will reach full charge — verify with a resting voltage of 8.2–8.4V before use.

Compatible Models

Agilia 4+ Agilia 6+ Agilia 8+ Agilia Link+ Volumat Agilia

Replaces Part Numbers

Z178899 179033-R2

Technical Specifications

Voltage7.4V
Amp Hours3350mAh
Capacity3350mAh
Rate24.79Wh
Net Weight99g /3.49 oz
Gross Weight124g /4.37 oz
Approximate Weight124g /4.37 oz
Dimension 70.00 x 36.90 x 18.80mm

Product Highlights

  • Brand: Fresenius
  • 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 Agilia pump alarms low battery within minutes of fitting a freshly charged replacement — is the cell faulty?

This is a BMS threshold issue, not a cell fault. The Agilia's battery monitor compares the new cell's state-of-charge report against a reference built from the previous cell's history, and the mismatch triggers a premature low-battery alarm. Complete one full charge-discharge cycle on the pump before clinical use — after one cycle the BMS resets its learned threshold and the alarm clears. Confirm resting voltage sits at 8.2–8.4V before returning the pump to service.

The Agilia won't power on at all after the replacement cell sat in storage — how do I recover it?

Li-ion cells self-discharge in storage, and if the cell has dropped below the Agilia's BMS recovery threshold (typically around 6.0V for a 7.4V nominal pack), the BMS will block power-on as a protection measure. Connect the pump to mains power and leave it on charge for a minimum of 30 minutes without pressing the power button — the charge IC runs a trickle pre-charge phase that brings the cell back above the BMS enable threshold before switching to normal charge current. If the charge indicator activates after that window, the recovery has started; allow a full charge to complete before powering on.

The pump shuts off unexpectedly mid-use during the first week with the new battery — what causes this?

New cells have not yet settled their internal resistance, and the Agilia's pump motor creates sharp current draw spikes during each delivery cycle. In the first 10 charge-discharge cycles, those spikes can pull cell voltage low enough to trip the BMS under-voltage cutoff — even though the cell appears well-charged at rest. The cutoff threshold on the Agilia BMS is set tight to protect both the cell and the infusion circuit. Run the battery through at least three full cycles under normal pump operation and the internal resistance will drop; the voltage sag under load reduces, and unexpected shutoffs stop.

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