Specification:
| NO. |
Items |
Specifications |
| 1 |
batteries |
3.7V 4000mah lipo battery |
| 2 |
Charge voltage |
4.2V |
| 3 |
Nominal voltage |
3.7V |
| 4 |
Nominal capacity |
4000mAh 0.2C Discharge |
| 5 |
Charge current
|
Standard Charging:0.2C
Rapid charge: 1.0C |
| 6 |
Standard Charging method |
0.5C CC(constant current)charge to 4.2V, then CV(constant voltage 4.2V)charge till charge current decline to ≤0.05C |
| 7 |
Charging time
|
Standard Charging:2.75hours(Ref.)
Rapid charge: 2hours(Ref.) |
| 8 |
Max.charge current |
0.5C |
| 9 |
Max.discharge current |
1.0C |
| 10 |
Discharge cut-off voltage |
2.5V0.25V(0.2C) |
| 11 |
Operating temperature |
Charging: 0 °C ~45 °C
Discharging:0 °C ~45 °C |
| 12 |
Storage temperature |
-10°C~ +45 °C |
| 13 |
Dimension |
Length:56±0.5mm (not including tabs)
Width:55±0.5mm
Thickness:10±0.2mm |
| 14 |
Drop Test |
The cell is to be dropped from a height of meter twice onto concrete ground. No fire, no leakage |
| 15 |
cycle time |
≥800times |
The differences for lithium polymer battery, li-ion battery, lifepo4 battery:
Safety:
Li-Po:
Safer than liquid Li-ion due to solid/polymer electrolyte (reduced risk of leakage).
Vulnerable to swelling if overcharged; requires protective circuits.
Cylindrical Li-ion:
Liquid electrolyte poses a higher risk of thermal runaway or explosion under abuse (e.g., overheating, short circuits).
Metal casing provides mechanical protection but traps heat.
LiFePO₄:
Best thermal stability (high decomposition temperature, ~510°C vs. ~200°C for NMC).
Lowest risk of fire/explosion; no cobalt/nickel toxicity.
Cycle Life
Li-Po: 300–500 cycles (depends on depth of discharge; shorter with frequent full discharges).
Cylindrical Li-ion: 500–1,000 cycles (longer with NCA/NMC chemistries in EVs).
LiFePO₄: 2,000–5,000+ cycles (longest lifespan, ideal for frequent charging/discharging).
Temperature Performance:
Li-Po: Operates well in moderate temperatures (0–60°C); sensitive to extreme cold/heat.
Cylindrical Li-ion: Similar to Li-Po but slightly better high-temperature tolerance in metal casings.
LiFePO₄: Performs best in wide temperature ranges (−20°C to 60°C), with minimal capacity loss in cold climates.
Weight & Design:
Li-Po: Lightest and most flexible; used in devices requiring custom shapes (wearables, thin gadgets).
Cylindrical Li-ion: Rigid and heavier per capacity; standardized sizes (18650) enable easy integration into large packs (e.g., laptops, EVs).
LiFePO₄: Slightly heavier than Li-Po but lighter than some cylindrical Li-ion in pouch form; less design flexibility than Li-Po.
Cost:
Li-Po: Moderate to high (due to cobalt/nickel content and custom manufacturing).
Cylindrical Li-ion: High for premium cells (e.g., NCA) but cost-effective at scale (common in EVs).
LiFePO₄: Lowest cost (cobalt/nickel-free materials, simpler manufacturing; ideal for large-scale energy storage).
Typical Applications:
Li-Po:
Portable electronics (smartphones, tablets, wearables), drones, RC toys, and thin devices needing flexible power.
Cylindrical Li-ion:
Electric vehicles (Tesla’s 21700 cells), laptops, power tools, and large energy storage systems (due to standardized sizes and high energy density).
LiFePO₄:
Electric buses, e-bikes, solar/wind energy storage, backup power, and applications prioritizing safety and long life (e.g., marine, grid storage).
