As e-bikes become increasingly popular worldwide, different battery shell types have been developed to match various bike designs, installation needs, and riding environments.

The battery shell (enclosure) doesn’t just affect appearance—it influences:

• installation method

• riding comfort and handling

• safety and durability

• maximum battery capacity

• cooling and protection

• maintenance convenience

This article introduces the most common e-bike battery shell types on the market and explains their features, advantages, and best-fit application scenarios.

 01. Hailong Battery

The most widely used and most compatible battery shell

 Key Features

• Compact and modern design

• Lockable base for anti-theft

• Slide-rail installation (easy on/off)

• Some models include USB ports

• Suitable for a wide range of capacities

 Ideal For

• Mountain bikes (E-MTB)

• City commuters

• Hybrid e-bikes

• DIY conversions

 Typical Specifications

• 36V / 48V / 52V

• 10Ah–20Ah (18650 or 21700 cells)

 Advantages

✔ Easy installation
✔ Highest market compatibility
✔ Stable waterproof performance
✔ Fits most controllers and motors

 Disadvantages

✘ Limited internal space for extra-large capacity

 02. Silver Fish Battery

Classic long-body design, widely used on commuter bikes

 Key Features

• Metal long-tube structure

• Carry handle for easy removal

• Mounted behind the seat tube or under the rear rack

• Allows larger internal space than Hailong shells

 Ideal For

• City commuter bikes

• General-purpose e-bikes

• Delivery bikes

• Some folding bikes

 Typical Specifications

• 36V / 48V

• 10Ah–20Ah

 Advantages

✔ Strong and durable structure
✔ Supports larger capacity packs
✔ Easy to repair or replace (open-shell design)

 Disadvantages

✘ Not suitable for lightweight or performance-oriented bikes

 03. Rear Rack Battery

Designed for commuting, cargo, and long-distance riding

 Key Features

• Installed on the rear cargo rack

• Large internal space

• Minimal impact on bike balance

• Compatible with many city bike frame designs

 Ideal For

• City commuting

• Touring bikes

• Cargo/utility e-bikes

• Senior riders

 Typical Specifications

• 48V / 52V

• 15Ah–25Ah

 Advantages

✔ Supports large capacities (20Ah+)
✔ Stable weight distribution
✔ Easy to install with standard racks

 Disadvantages

✘ Heavier and bulkier
✘ Not suitable for mountain or off-road bikes

 04. Triangle Battery Pack (Frame Bag Battery)

Best choice for long-range, high-capacity riding

 Key Features

• Installed inside the bike’s frame triangle

• Supports customized sizes and capacities

• Often uses 21700 cells for higher energy density

• Excellent cooling and power delivery

 Ideal For

• Mountain bikes

• Long-distance touring

• Off-road and high-power riding

 Typical Specifications

• 48V / 52V / 60V

• 15Ah–35Ah

 Advantages

✔ Extra-large capacity possible
✔ Low center of gravity → stable handling
✔ Suitable for high-current controllers

 Disadvantages

✘ Appearance is less refined than molded plastic shells
✘ Requires straps or a custom bracket

 05. Moped-Style Battery Box

Made for high-power and heavy-duty applications

 Key Features

• Large plastic or metal enclosure

• Designed for high-discharge packs

• Suitable for 1000W–2000W+ systems

• Enhanced protection against impact and weather

 Ideal For

• E-moped bikes

• High-speed e-bikes

• Heavy-duty delivery or cargo bikes

 Typical Specifications

• 48V / 60V / 72V

• 20Ah–40Ah

 Advantages

✔ Massive capacity available
✔ Supports very high discharge currents
✔ Durable, impact-resistant, waterproof

 Disadvantages

✘ Too large/heavy for standard bicycles

 06. Seatpost / Hidden Frame Battery

Designed for lightweight folding and commuter e-bikes

 Key Features

• Slim tube-shaped design

• Installed inside the seatpost or hidden in the frame

• Clean, minimalist appearance

• Built primarily for lightweight mobility

 Ideal For

• Folding e-bikes

• Lightweight city bikes

• Brand-specific OEM models (FIIDO, DYU, etc.)

 Typical Specifications

• 36V / 48V

• 7Ah–12Ah

 Advantages

✔ Very clean look
✔ Space-saving
✔ Portable and lightweight

 Disadvantages

✘ Small capacity due to limited internal space

 07. How to Recommend the Right Battery Shell to Your Customers

Here’s a quick reference table:

 Final Summary

The battery shell type determines:

• installation method

• maximum capacity

• weight and balance

• waterproof & impact resistance

• compatibility with the frame

• riding comfort and safety

Choosing the right battery is not only about voltage and capacity—the shell structure matters just as much.