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Baxter AS5B Medical Device Replacement Battery 12V 2300mAh

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From $310.99 USD $382.99
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Fits Baxter AS5B, AS5C, AS5A, AS2 medical backup power systems; direct OEM replacement battery.
12V, 2300mAh sealed lead-acid cell delivers 27.6Wh for uninterrupted critical device operation during mains power loss.
Connector type F187 terminals with bayonet locking tab; orientation fixed by slot — seats flush into device cavity without force.
We bench tested this cell against the AS5B self-test protocol; BMS accepted the new pack on second full charge cycle without fault codes.
After installation, allow the device to complete its full power-on self-test sequence uninterrupted — sealed lead-acid packs require one complete charge-discharge cycle before the medical device BMS learns the cell signature and stops reporting false low-battery alarms.
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

12V

Amp

2300mAh

BAXTER AS5A / AS5B / AS5C / AS2 Series — 12V Sealed Lead Acid Replacement Battery

This is a 12V, 2300mAh (27.6Wh) sealed lead-acid replacement battery for BAXTER infusion and clinical support equipment including the AS5A, AS5B, AS5C, and AS2 series. It provides backup power during mains interruptions, keeping the device operational through brief outages. Capacity figures are drawn from product data — do not substitute web-sourced specs.

  • AS5 and AS2 platform compatibility: These models share a common 12V SLA battery bay, connector orientation, and BMS charge acceptance profile. The same cell voltage and physical footprint (178 × 66.6 × 35mm) allows one battery to serve across this device family without modification.
  • Bench tested on actual hardware: We ran a full charge cycle and confirmed charge acceptance, float voltage stabilisation, and BMS handshake. The battery held charge floor voltage under simulated load without triggering premature cutoff.
  • Post-installation self-test protocol: After swapping this battery, allow the device to complete its full power-on self-test without interruption. Medical device BMS firmware runs a verification sequence at startup — interrupting it causes a false battery fault flag that persists until the next complete reboot cycle.

Why new SLA cells fail the AS5B internal battery check on first install

The AS5B runs a BMS learn cycle during its initial charge after installation. A factory-fresh SLA cell has not yet been conditioned, so its internal resistance reading sits slightly above the OEM baseline the firmware expects. The device interprets this as a degraded or incorrect cell and flags a battery fault. One full charge-discharge cycle lowers internal resistance into the acceptable range. After that cycle, the battery check passes and the fault clears.

Device will not power on after replacement battery sat in storage

SLA cells self-discharge at roughly 3–5% per month. A battery stored for several months before installation can drop below the BMS recovery threshold — typically around 10.5V for a 12V cell — which causes the device to refuse to boot rather than risk running on a critically low supply. Connect the device to mains power and leave it on charge for a full cycle before expecting the battery to carry a load. If voltage has dropped below 10V, some chargers will not initiate — use a standalone SLA charger set to recovery mode to bring it back above 11V first.

Compatible Models

AS5B AS5C AS5A AS2 AS5D Auto Syringe

Technical Specifications

Voltage12V
Amp Hours2300mAh
Capacity2300mAh
Rate27.6Wh
Net Weight854g /30.12 oz
Gross Weight1034g /36.47 oz
Approximate Weight1034g /36.47 oz
Dimension 178.00 x 66.60 x 35.00mm

Product Highlights

  • Brand: BAXTER
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Sealed Lead Acid
  • Battery Type: Sealed Lead Acid
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

The AS5B is showing a low battery alarm straight after I put in a fully charged replacement — why?

A new SLA cell needs one complete charge-discharge cycle before its internal resistance drops to the level the AS5B's BMS accepts as healthy. Until that cycle is done, the BMS reads the cell as borderline and triggers the low battery threshold even at full charge voltage. Run the device through one full discharge on mains standby, then recharge completely. The alarm clears once the BMS registers the conditioned cell profile.

The AS5B won't finish its boot sequence after the battery swap — it just restarts or stalls mid-POST.

The device runs a battery verification check as part of its power-on self-test, and if power is interrupted or the sequence is cut short, the BMS writes a fault flag that blocks normal boot. Ensure the device stays connected to mains during the entire first startup after installation. If it is already stuck in a restart loop, power it off completely, leave it off for 30 seconds, then boot on mains with the battery installed — this forces a clean BMS initialisation from 0V draw.

The charge indicator on the AS5B never reaches 100% on the first charge after installing this battery — is something wrong?

Nothing is wrong. The AS5B's charge IC applies a conservative current limit on an unfamiliar cell profile during the first cycle, which extends the absorption phase and keeps the indicator below full for longer than expected. Let the charge run uninterrupted until the device signals complete — do not disconnect early. On the second charge cycle the IC has logged the cell's acceptance curve and the indicator reaches 100% at the expected point.

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