The Green Cell Ultra laptop battery (M5Y1K) is a precisely engineered replacement for the Dell Inspiron 15/17 5xxx series. The Ultra series provides higher capacity than the original battery, delivering extended runtime for maximum mobility. Powered by Green Cell Li-Ion / Li-Polymer cells, it delivers real capacity and long runtime — not just on paper.
Why choose this battery?
- Guaranteed compatibility – precisely designed to fit the Dell Inspiron 15/17 5xxx series
- Real capacity – 5200 mAh (74Wh) of genuine, measurable performance
- Green Cell cells – proprietary, reliable Li-Ion / Li-Polymer cell technology
- Built-in protection – overcharge and over-discharge protection
- Plug & Play – connect and use immediately, no configuration required
- 12-month warranty – backed by Green Cell customer support
Compatible models
This battery is compatible with the following Dell models:
Inspiron 15 5551, 5552, 5558, 5559, Inspiron 17 5755
Manufacturer part number: M5Y1K
Technical specifications
| Feature | Value |
|---|
| Product code (SKU) | DE77ULTRA |
| Part number | M5Y1K |
| Voltage | 14.8V / 14.4V |
| Capacity | 5200 mAh / 74Wh |
| Number of cells | 8 |
| Cell type | Li-Ion |
| Cell manufacturer | Green Cell |
| Warranty | 12 months |
| Condition | New |
Frequently asked questions
Will this battery fit my exact laptop model?
Yes – every battery undergoes physical and electronic compatibility verification during development. This battery precisely fits all listed Dell Inspiron 15/17 5xxx models and follows the original charging protocol.
How long will the battery last on a single charge?
Actual runtime depends on usage (screen brightness, CPU load, Wi-Fi), but the 5200 mAh capacity typically covers a full working day for standard office tasks. It reaches peak performance after the first few charge cycles.
How can I extend the battery's lifespan?
Avoid regularly keeping it at 100% charge or letting it fully discharge. The 20–80% range is easiest on the cells. Before storage, charge to around 50% and keep in a cool, dry place.
