Product Overview
This B21N1818-3 replacement battery is organized from the listed product data. Key details include Voltage: 7.7V, Capacity: 37WH/4850mAh (High Capacity), Battery Type: Premium Li-ion. Compatibility includes VivoBook 14 Series: X409, X409F, X409FUA, X409FB, X509, X545 and Y Series: Y4200F, Y4200FB, Y5200F, Y5200FB and additional models below.
Specs
| Battery Model | B21N1818-3 |
|---|---|
| Voltage | 7.7V |
| Capacity | 37WH/4850mAh (High Capacity) |
| Battery Type | Premium Li-ion |
| Color | Black |
| Condition | Brand New (100% New, 1-year warranty) |
| Certification | CE, FCC, RoHS compliant |
Parts
- B21N1818-3
- B21N1818-1
Models
- VivoBook 14 Series: X409, X409F, X409FUA, X409FB, X509, X545
- Y Series: Y4200F, Y4200FB, Y5200F, Y5200FB
- FL8700 Series: FL8700, FL8700D, FL8700F
FAQ
Which battery references should I compare with the original pack?
The listed battery model is B21N1818-3. Other replacement references include B21N1818-3, B21N1818-1; compare the label on the original battery before ordering.
What electrical specifications does this replacement battery use?
The listed voltage is 7.7V, capacity is 37WH/4850mAh (High Capacity), and battery type is Premium Li-ion. These values should match the original battery requirements.
Which device models are listed as compatible?
The product is listed for VivoBook 14 Series: X409, X409F, X409FUA, X409FB, X509, X545; Y Series: Y4200F, Y4200FB, Y5200F, Y5200FB. Check the exact device series, battery model and connector position rather than relying only on the brand name.
What should I check before replacing the battery?
Compare the original model number, voltage, capacity, connector and physical fit with the listed specifications. If any key detail differs, confirm compatibility before installation.
Note:
This is not a complete list or inclusion of all compatible laptop models. You can open the back of your laptop to check the original battery model. If you have any compatibility questions, please contact us online.The casing is made of durable materials, the mainboard adopts advanced technology, and the battery core is produced with high-quality raw materials to ensure that it will not be damaged after long-term use.
Our products are equipped with multiple protection technologies such as overvoltage, overcurrent, and overcharge to effectively protect the safety of batteries and equipment.
Shipping Methods
| Shipping Methods | Ship To | Est. Delivery Time | Shipping Cost | Taxes & Fees |
|---|---|---|---|---|
| USPS / DHL | United States | 10-15 business days | Free | Free |
| Canada Post | Canada | 10-15 business days | Free | Free |
| Royal Mail / Yodel | United Kingdom | 15-20 business days | Free | Free |
| DHL | Germany | 15-20 business days | Free | Free |
| La Poste | France | 15-20 business days | Free | Free |
| Correios | Mexico/Spain/IT | 15-25 business days | Free | Free |
| Local Carriers | SE Asia / East Asia | 5-10 business days | Free | Free |
| Local Carriers | Rest of Europe | 20-25 business days | From $5.99 | Free |
| Local Carriers | UAE / Saudi Arabia / Israel | 16-20 business days | From $7.99 | Free |
📦 Shipping & Tracking Information
Looking for faster shipping? We offer local warehousing services. Please visit our "Local Delivery" page for items available for immediate dispatch.
1. How to Track Your Package:
Please choose the tracking link that corresponds to your destination:
- Europe & The Americas: 17track.net/en
- The Middle East: mena56.com
- Asia: 17exp.kingtrans.cn
Need Help?
If you cannot find your package on any of the above websites, please contact us immediately.
📧 Email: sales@batterymall.com / info@batterymall.com
📱 WeChat/WhatsApp: (+86) 198 6775 1872 / (+86) 191 2767 3310
🚚 Estimated Delivery Time
(1) Shipping from China:
- To Asia: 5-20 business days
- To North America: 10-15 business days
- To Europe/South America: 15-20 business days
(2) Shipping from Local Warehouses:
- From US Warehouse: 3-5 business days
- From European Warehouse: 2-10 business days
- From Russian Warehouse: 3-5 business days
Please note: Exact arrival times depend on the specific country and customs processing.
⚠️ Tax & Customs Information:
Global product prices include customs duties (some countries require a tax ID). Please refer to the settlement invoice for specific shipping costs. Special handling is required if your package is inspected.
Payment Methods
Paypal
Payments by PayPal, no PayPal account required. Paypal is safe and free for buyers.
PayPal account: Payment@batterymall.com
Account Name: ShenZhen KingSener Science and Technology Co., Ltd
Credit or debit card
VISA, MasterCard, the United States n Express,Maestro & Laser Card, APPLE Pay,etc.
PayPal never shares your financial information with us.
WeChat Pay
Currently only supports QR code payment. Please contact WeChat customer service and go to WeChat App to scan the QR code to complete the payment.
Google Pay
Pay with Google Pay, which is more convenient and faster.
Apple Pay
If you use an Apple device, you can use Apple Pay to pay, which is more convenient and faster.
Bank Transfer
Q&A
Quick FAQ:Laptop Battery Care & Troubleshooting
- How long does a KingSener battery last?2 to 3 years (approx. 500-800 charge cycles) under normal temperatures.
- Laptop says "Battery Not Detected". How to fix?1. Hard Reset: Unplug AC, remove battery, hold power button for 30 seconds.
2. Clean Contacts: Wipe metal connection pins.
3. Reset Drivers: Uninstall battery drivers in Device Manager, then restart.
4. Update BIOS: Ensure motherboard firmware is up to date. - Can I leave my laptop plugged in 24/7?Yes, the built-in TI chip prevents overcharging. Tip: To prevent long-term cell swelling, unplug and drain the battery to 40% twice a month.
- How do I store a laptop battery long-term?Store it at 50% charge in a cool, dry place. Never store at 0% or 100%. Cycle the battery every 3 months to maintain chemical activity.
-
Are KingSener batteries safe?Yes. All batteries feature built-in IC protection against short-circuits, over-voltage, and overheating. Fully CE, FCC, and RoHS certified.