EM10 Battery Pack – B Hidden Down-Tube 36V/48V Li-ion

Brand: TanLuZhe
Compatibility: EM10
Mounting Type: Fully hidden in the frame down-tube
Removal & Locking: Down-taken system with double lock
Battery Cells: Samsung 21700 Li-ion, up to 42 cells (10S4P for 36V / 13S3P for 48V)
Voltage & Capacity Range:
• 36 V 20 Ah (27.5 – 42 V) – ~720 Wh
• 48 V 15 Ah (36 – 54.6 V) – ~720 Wh
Charging Time:
• 36V 20Ah: 6–7 h (3A, DC 2.1 mm connector)
• 48V 15Ah: 5–6 h (3A, DC 2.1 mm connector)
Certifications: CE, UN38.3
Weight: ~4.0 kg

Help me understand it:

Weight ~4.0 kg: Higher capacity cells with solid casing, offering a balance between energy storage and durability.

Pros & Cons

🔹 36V 20Ah (~720 Wh)

Pros:

• Higher Ah capacity = extended riding range.

• More efficient with lower power motors (250W–500W).

• Lower thermal and mechanical stress on components.

• Ideal for endurance-focused, long-distance pedal-assist riding.

Cons:

• Lower peak power output compared to 48V.

• Less suitable for steep hills or heavy load acceleration.

🔹 48V 15Ah (~720 Wh)

Pros:

• Higher peak power = better hill-climbing and high-speed performance.

• Best for motors in the 500W–1000W range.

• Strong acceleration and torque under load.

• More efficient at sustaining higher cruising speeds.

Cons:

• Slightly lower Ah means shorter range if used at same power output as 36V.

• Increased wear risk if paired with components not rated for 48V.

• Slightly more expensive to replace due to higher voltage parts.

Expert Advice Summary

Go with 36V 20Ah if:

• You prioritize range, smoother rides, and energy efficiency.

• Your motor is 500W or less and you rely more on pedal assist than throttle.

Choose 48V 15Ah if:

• You want stronger acceleration, better climbing performance, and off-road capability.

• You ride at higher speeds or often carry heavier loads.

TanLuZhe: A specialized e-bike battery manufacturer focused on high-capacity, robust builds.
EM10 Compatibility: Designed to fit perfectly inside the EM10’s down-tube without external brackets.
Fully Hidden Mounting: Maintains frame aesthetics and balanced handling.
Down-taken & Double Lock: Easy removal for charging with enhanced theft protection.
Samsung 21700 Li-ion (42 cells): High energy density and long cycle life.
36 V 20 Ah / 48 V 15 Ah: Balanced options for endurance or power-focused riding.
CE & UN38.3: Meets international safety and battery transport standards.

🔋 Battery Comparison: 36V 20Ah vs 48V 15Ah