Hailong Polly DP7 eBike Battery – 36V 48V 52V 60V 72V High-Capacity Lithium Battery

High-Capacity 21700 Lithium Battery for Hailong eBike Systems

Upgrade your electric bike with a high-capacity Hailong Polly DP7 lithium battery designed for compatible eBike and electric conversion systems.

Available in multiple voltage and capacity configurations, this downtube frame battery is designed for riders who need additional energy capacity for commuting, long-distance riding, cargo applications, off-road riding, and high-power eBike conversion projects.

Choose from 36V, 48V, 52V, 60V, and 72V configurations with capacity options ranging from 25Ah to 60Ah.

Key Features

• Battery Type: 21700 Lithium Battery

• Battery Style: Hailong / Polly DP7 downtube battery

• Voltage Options: 36V / 48V / 52V / 60V / 72V

• Capacity Options: 25Ah / 30Ah / 35Ah / 40Ah / 45Ah / 50Ah / 60Ah

• BMS: Built-in 80A protection board

• Charger: 5A charger included as a gift

• Cycle Life: Over 80% capacity after 1,000 cycles, according to supplied specifications

• Certification: CE / FCC / RoHS

• Warranty: 1 year

• Application: eBike / electric bicycle/conversion kit

• Origin: Mainland China

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High-Capacity 21700 Battery Cells

The Polly DP7 uses 21700 lithium battery cells, a larger-format lithium-ion cell design commonly used in high-capacity battery packs.

The available capacity options provide riders with flexibility depending on their desired range and available battery space.

Available Capacities

• 25Ah

• 30Ah

• 35Ah

• 40Ah

• 45Ah

• 50Ah

• 60Ah

Higher-capacity batteries store more energy, but they can also be larger and heavier. Confirm the dimensions and weight of your selected configuration before ordering.

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Multiple Voltage Options

Choose the battery voltage that matches your electric bike or conversion system:

36V eBike Battery

Designed for compatible 36V systems.

48V eBike Battery

A common choice for commuter, mountain, cargo, and performance eBikes.

52V eBike Battery

Designed for compatible 52V systems and commonly used in higher-performance eBike applications.

60V eBike Battery

Designed for compatible high-voltage electric bike and conversion systems.

72V eBike Battery

Designed for compatible high-performance electric systems requiring a 72V battery.

Important: Voltage is not interchangeable. Your motor and controller must support the selected battery voltage.

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Battery Energy Capacity

Battery energy can be estimated using:

Voltage × Amp-Hours = Watt-Hours

Examples:

Battery	Approx. Nominal Energy
36V 25Ah	900Wh
48V 25Ah	1,200Wh
52V 25Ah	1,300Wh
60V 25Ah	1,500Wh
72V 25Ah	1,800Wh
48V 40Ah	1,920Wh
52V 40Ah	2,080Wh
60V 40Ah	2,400Wh
72V 40Ah	2,880Wh
48V 60Ah	2,880Wh
52V 60Ah	3,120Wh
60V 60Ah	3,600Wh
72V 60Ah	4,320Wh

Actual usable energy and riding range vary based on motor efficiency, controller settings, rider weight, speed, terrain, temperature, tire pressure, and riding conditions.

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Built-In 80A BMS

The battery includes a stated 80A BMS protection board.

A Battery Management System helps monitor and protect lithium battery cells against conditions such as:

• Overcharge

• Over-discharge

• Over-current

• Short circuit

• Cell imbalance

The BMS current rating should be considered together with your motor and controller specifications.

Do not assume an 80A BMS means the battery should be used continuously at 80A. Verify the manufacturer's continuous and peak current specifications for your selected battery configuration.

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Compatible Motor Power

The supplied specifications list compatibility with motor systems ranging from:

• 250W

• 350W

• 500W

• 750W

• 1,000W

• 1,500W

• 2,000W

• 3,000W

and voltage configurations of:

36V / 48V / 52V / 60V / 72V

Motor and controller compatibility must be verified before installation.

A battery's voltage and BMS specifications must match the complete electrical system.

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Hailong Polly DP7 Downtube Battery

The Polly DP7 is designed as a downtube frame-mounted battery for compatible Hailong-style battery mounting systems.

The downtube configuration can provide a practical way to mount a larger-capacity battery while keeping the battery positioned within the frame area.

Before ordering, verify:

• Battery case dimensions

• Mounting rail

• Mounting holes

• Connector type

• Connector polarity

• Battery clearance

• Frame compatibility

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5A Charger Included

A 5A charger is listed as included as a gift with the battery.

The charger must match the selected battery voltage and charging requirements.

Typical lithium-ion full-charge voltages are:

Nominal Battery	Typical Full Charge
36V	42V
48V	54.6V
52V	58.8V
60V	67.2V
72V	84V

Always verify the charger output before connecting it to your battery.

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Long Cycle Life

The supplied specifications state that the battery can maintain over 80% capacity after 1,000 cycles.

Actual battery life depends on charging habits, storage conditions, temperature, discharge depth, operating current, and overall battery maintenance.

For longer battery life:

• Avoid unnecessary deep discharges

• Use the correct charger

• Avoid extreme temperatures

• Store the battery according to manufacturer recommendations

• Inspect the battery and wiring regularly

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1-Year Warranty

This battery is listed with a 1-year warranty.

Warranty coverage should be confirmed with the seller before purchase, including coverage terms, exclusions, shipping requirements, and procedures for warranty claims.

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Battery Specifications

Specification	Details
Product	Polly DP7 Hailong Lithium Battery
Cell Type	21700 Lithium
Voltage	36V / 48V / 52V / 60V / 72V
Capacity	25Ah / 30Ah / 35Ah / 40Ah / 45Ah / 50Ah / 60Ah
BMS	Built-in 80A protection board
Charger	5A charger included
Battery Style	Downtube / Frame Battery
Motor Range Listed	250W–3,000W
Certification	CE / FCC / RoHS
Cycle Life	Over 80% after 1,000 cycles*
Warranty	1 Year
Cell Format	21700
Origin	Mainland China

*Based on the supplied product specifications.

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Important Compatibility Information

Because this product is offered in multiple voltage and capacity configurations, select the correct option for your electrical system.

Before ordering, confirm:

Battery Voltage: Must match your motor/controller requirements.

Controller: Must support the selected battery voltage and current requirements.

BMS: Verify continuous and peak current requirements.

Charger: Must match the selected battery's charging voltage.

Mounting: Confirm the Polly DP7/Hailong mounting system fits your frame.

Connectors: Confirm connector type and polarity.

Capacity: Choose a capacity that physically fits your bike and meets your range requirements.

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Frequently Asked Questions

What voltage options are available?

The listing provides 36V, 48V, 52V, 60V, and 72V options.

What capacity options are available?

Available capacities are listed as 25Ah, 30Ah, 35Ah, 40Ah, 45Ah, 50Ah, and 60Ah.

What type of battery cells are used?

The product uses 21700 lithium battery cells.

Does the battery have a BMS?

Yes. The supplied specifications list a built-in 80A BMS protection board.

Is a charger included?

Yes. A 5A charger is listed as included as a gift. Confirm that the supplied charger matches your selected battery voltage before use.

Can I use this battery with a 3,000W motor?

The product specifications list compatibility with motors up to 3,000W, but actual compatibility depends on the battery voltage, BMS current capability, controller, motor, wiring, and connectors.

Which battery capacity should I choose?

Choose based on your desired range, available frame space, weight requirements, and electrical system. Higher Ah generally means greater stored energy when voltage is held constant.

Is this battery compatible with a Hailong mount?

The product is identified as a Polly DP7/Hailong-style downtube battery. Confirm your existing mounting rail and dimensions before ordering.

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Upgrade Your eBike with a High-Capacity Battery

Whether you're building a custom electric bike, upgrading a commuter eBike, or converting a bicycle to electric power, the Hailong Polly DP7 21700 lithium battery offers multiple voltage and capacity configurations for compatible systems.

Available in 36V, 48V, 52V, 60V and 72V.

Available capacities from 25Ah to 60Ah.

Power Your Ride. Charge Anywhere. Ride Longer.

Shop high-capacity eBike batteries at ChargeMyEBike.com.