## Common ground
All options refer to rechargeable batteries and battery packs, differing only in their chemical composition.
## Options at a glance
**8507.20 – Lead acid**
- **Defining trait:** Uses lead and sulfuric acid; heavy but low-cost and widely used in vehicles.
- **Typical examples:** Car starter batteries, backup power systems.
- **Best fit when:** High current output needed, cost is key, and weight isn’t a concern.
**8507.30 – Nickel cadmium (NiCd)**
- **Defining trait:** Uses nickel and cadmium; durable but suffers from memory effect and contains toxic cadmium.
- **Typical examples:** Power tools, older cordless phones.
- **Best fit when:** Long cycle life and high discharge rates are needed, despite environmental concerns.
**8507.50 – Nickel metal hydride (NiMH)**
- **Defining trait:** Uses nickel and hydrogen-absorbing alloy; higher capacity than NiCd, less memory effect.
- **Typical examples:** Digital cameras, hybrid vehicles, remote controls.
- **Best fit when:** Balanced performance, moderate energy density, and no cadmium.
**8507.60 – Lithium-ion (Li-ion)**
- **Defining trait:** Uses lithium compounds; high energy density, lightweight, but requires protection circuits.
- **Typical examples:** Smartphones, laptops, electric bikes, power banks.
- **Best fit when:** Lightweight, long runtime, and compact size are essential.
**8507.80 – Nickel iron (NiFe)**
- **Defining trait:** Uses nickel and iron; very long lifespan and safe, but low energy density and high self-discharge.
- **Typical examples:** Off-grid solar systems, industrial backup power.
- **Best fit when:** Extreme durability and safety matter more than size or efficiency.
## Key differences
| Feature | Lead acid | NiCd | NiMH | Li-ion | NiFe |
|---------------------|---------------|--------------|--------------|--------------|--------------|
| Energy density | Low | Medium | Medium | High | Low |
| Weight | Heavy | Medium | Medium | Light | Heavy |
| Lifespan | Short–medium | Medium | Medium | Long | Very long |
| Environmental risk | High (acid) | High (Cd) | Low | Medium | Low |
## How to choose
- Does it power a car or backup system? → 8507.20
- Is it used in tools with high current needs and durability required? → 8507.30
- Is it for consumer electronics needing moderate capacity and no cadmium? → 8507.50
- Is it for a smartphone, laptop, or portable device where size and weight matter? → 8507.60
- Is it for off-grid solar or industrial use where lifespan and safety are critical? → 8507.80
## Overlaps & pitfalls
A battery might fit multiple categories (e.g., a NiMH pack could also be used in tools). The main function determines the correct HS Code. If unsure, prioritize the **primary application** and **dominant technology**. Avoid assuming "lithium" means Li-ion—some lithium-based batteries are not covered here