Compaq Presario A900 Replacement Battery 10.8V 8800mAh
This product ships directly from our Manufacturer’s Warehouse and is usually delivered within 5 – 8 business days to your doorstep.
WECARE5
Check that your old battery model number and device model to match our description. This makes sure they work together.
We ship your order same day if you buy it before 4 PM EST.
Compaq Presario A900 Replacement Battery 10.8V 8800mAh - is backordered and will ship as soon as it is back in stock.
Let customers speak for us
Send Your Battery Photo
Expert Technician Help
Snap a photo or video of your battery and send it to us. We'll identify the exact replacement—fast and hassle-free. Our team has helped thousands of customers find the right battery quickly and easily.
POST YOUR BATTERY IMAGE
Product & Solutions Expert
✉ sales@batteryweb.com
Battery Care Tips
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
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
⚠️ 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.
Compaq Presario A900 Replacement Battery 10.8V 8800mAh - is backordered and will ship as soon as it is back in stock.
Voltage
10.8V
Amp
8800mAh
Compaq Presario A900 / C700 Series — 10.8V Li-ion Replacement Battery (436281-241)
This is a 10.8V, 8800mAh (95.04Wh) Li-ion battery for the Compaq Presario A900 and C700 series notebooks. It replaces OEM part numbers 436281-241, HSTNN-DB42, HSTNN-LB42, and several other cross-references listed below. Fits directly into the battery bay without modification.
- A900 and C700 platform compatibility: Both the A900 and C700 lines share the same 10.8V battery rail, connector pinout, and BMS handshake protocol — that is why a single cell covers both chassis variants. The EEPROM on this pack carries the correct capacity and chemistry flags the Compaq BIOS expects to read on power-on.
- Bench tested on actual hardware: We ran this cell through charge, discharge, and reconnect cycles on a Presario C700 unit. The BMS communicated correctly with the system board, charge acceptance was normal from first cycle, and no false fault flags appeared in the BIOS hardware monitor.
- First-cycle calibration on Presario notebooks: After installing this battery, run the laptop down to hibernate cutoff under normal use — do not force-shutdown — then charge uninterrupted to 100%. This single full cycle lets the BIOS battery learn routine sync against the new cell and clears the inaccurate health warning that almost always appears after a cell swap on this platform.
BIOS reporting poor battery health immediately after installing a new cell
The Presario BIOS stores capacity and cycle-count data from the previous cell in a learn table. When a new pack is installed, the stored data does not match the new EEPROM values, and the firmware flags it as degraded before any real measurement has taken place. This is not a fault with the replacement cell. One complete discharge-to-hibernate followed by an uninterrupted charge to 100% resets the learn table. After that cycle, BIOS health reporting reflects actual cell state.
Presario shutting down at 20–30% charge shown on screen
This happens when the fuel gauge IC has not yet calibrated against the new cell's voltage curve. The gauge reports 25% remaining while the actual cell voltage has already dropped below the safe cutoff threshold under full CPU and display load — the system shuts down to protect the cell. It is not a defective battery. Run two full discharge-to-hibernate and charge-to-100% cycles without interrupting the charge phase. After the second cycle, the fuel gauge tracks the new cell accurately and shutdowns stop occurring above 10%.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Compaq
- 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 Presario shows "plugged in, not charging" after I swapped the battery — what's happening?
The Compaq BIOS on this platform sometimes refuses to initiate charging when it does not recognise the new pack's EEPROM data on first boot. Shut the laptop down completely — not restart — remove the AC adapter for 30 seconds, then reconnect AC before powering on. This forces a fresh BIOS power negotiation cycle and charging typically begins normally. If it persists after two cold boots, check that the battery connector is fully seated — a partial connection on this chassis passes enough signal to power on but not enough for charge handshake.
The battery meter is jumping around wildly — showing 60%, then 80%, then 45% within minutes. Is the cell faulty?
The fuel gauge IC on the Presario system board calibrates itself against charge and discharge data accumulated over several cycles. A brand-new cell has no history in that IC, so the reported percentage is essentially a guess for the first two to three full cycles. Run the laptop on battery until it hibernates, then charge uninterrupted to 100% — repeat this twice. After the second full cycle, the gauge stabilises and percentage readings become accurate. No hardware fault is involved.
System info shows this battery as 47Wh but the spec says 95.04Wh — why is it reporting half the capacity?
The Wh figure in system information is read from the EEPROM on the battery pack and compared against the value the BIOS expects from its stored learn table — if the old battery was a lower-capacity 47Wh unit, the BIOS table still holds that number until it runs a fresh learn cycle. The cell itself is 95.04Wh as specified. Perform one full discharge to hibernate cutoff followed by an uninterrupted charge to 100%, and the BIOS will rewrite the learn table entry with the correct 95.04Wh figure from the new pack's EEPROM.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
