300mAh USB-C Battery for SRAM AXS / eTap – Carbon Fiber
300mAh USB-C Battery for SRAM AXS / eTap – Carbon Fiber
300mAh USB-C Battery for SRAM AXS / eTap – Carbon Fiber
300mAh USB-C Battery for SRAM AXS / eTap – Carbon Fiber

300mAh USB-C Battery for SRAM AXS / eTap – Carbon Fiber

$139.99
Carbon Finish:3K Carbon Weave
Menge:

Direct USB-C Charging. One Less Charger to Pack.

Make charging your electronic shifting system easier.

This aftermarket 300mAh rechargeable battery features an integrated USB-C charging port, allowing you to charge the battery directly without using a separate SRAM-style charging cradle.

Simply connect a compatible USB-C cable and power source directly to the battery.

Designed for compatible SRAM AXS / eTap rear derailleurs, it combines convenient direct charging, a lightweight carbon fiber housing, and multiple electrical protection features in one compact battery.

300mAh Rated Capacity

The battery is rated at:

  • Capacity: 300mAh

  • Voltage: 7.4V

  • Energy: 2.22Wh

It can be used as a replacement or spare battery for compatible SRAM AXS / eTap rear derailleurs.

Actual operating time may vary depending on shifting frequency, temperature, battery condition, derailleur model, and riding conditions.

Approximately 20.5g Lightweight Design

The pictured 300mAh battery weighs approximately 20.5g.

The lightweight carbon fiber housing helps keep overall system weight low while maintaining a compact battery structure.

Actual weight may vary slightly depending on the carbon finish and production tolerances.

Two Carbon Fiber Finishes

Choose between two different exterior finishes:

3K Carbon Weave

Classic and uniform woven carbon fiber appearance.

Forged Carbon Pattern

Irregular forged-carbon-style pattern for a more distinctive appearance.

Due to the nature of carbon fiber materials and manufacturing, the exact pattern may vary slightly between individual batteries.

USB-C Direct Charging

The integrated USB-C charging port allows the battery to be charged directly without removing it and placing it into a separate charging cradle.

This means fewer accessories to carry when traveling or riding.

Simply connect a compatible USB-C charging cable and power source to begin charging.

PD / QC Compatible Power Source Support

According to the supplier, the charging system supports compatible PD and QC power sources.

Charging performance may vary depending on:

  • Charger

  • USB-C cable

  • Battery state

  • Power-source specifications

Support for PD or QC power sources does not necessarily mean that the battery will charge at the maximum fast-charging output of the charger.

Sealed Charging Structure

The battery uses a multi-layer sealing design intended to improve protection during everyday riding conditions.

When the battery is installed on the rear derailleur, the main external sealing surface is created between the battery and rear derailleur interface.

The sealing gasket is located on the rear derailleur side, similar to the original battery mounting structure.

This means the battery and derailleur work together to form the external seal when correctly installed.

Fully Potted Internal Electronics

Inside the battery, the charging-port area and internal electronic components are fully sealed with protective potting compound.

This construction helps isolate the internal circuitry from moisture and contaminants.

Unlike a simple exposed USB-C socket connected directly to the battery terminals, the internal electronics and charging interface are protected within the sealed battery structure.

This provides an additional layer of protection for real-world cycling use.

Smart USB-C Power-On Protection

The USB-C interface incorporates protocol-controlled power activation.

The charging port does not remain continuously powered.

Electrical output is enabled only after a compatible charging protocol is successfully detected and established.

This means that under normal conditions, simply having moisture or water inside the USB-C port does not automatically place the charging contacts under active power.

The design helps reduce the possibility of an electrical short circuit caused by moisture entering the USB-C charging interface during riding.

Protection Logic

  • USB-C interface remains unpowered before protocol detection

  • Compatible charging connection must be successfully established

  • Power is activated only after protocol recognition

  • Helps reduce the risk of moisture-related short circuits

Multi-Layer Moisture Protection

The battery therefore uses several complementary protection methods:

  • Rear-derailleur interface sealing

  • Derailleur-side sealing gasket

  • Fully potted internal electronics

  • Sealed internal charging circuitry

  • Protocol-controlled USB-C power activation

Together, these features are designed to provide better protection against moisture encountered during normal cycling conditions.

Important: This product should not be considered completely waterproof or suitable for prolonged submersion. Always keep the USB-C port clean and dry whenever possible.

Integrated Battery Protection

According to the supplier, the built-in protection circuit includes:

  • Overcharge protection

  • Over-discharge protection

  • Overcurrent protection

  • High-temperature protection

  • Low-temperature protection

These protection functions help manage battery operation and charging under normal use.

Always use and charge the battery according to the supplied instructions.

SPECIFICATIONS

Product Type: Aftermarket rechargeable rear derailleur battery

Intended Application: Compatible SRAM AXS / eTap rear derailleurs

Rated Capacity: 300mAh

Rated Voltage: 7.4V

Rated Energy: 2.22Wh

Charging Port: USB-C

Housing Material: Carbon fiber

Carbon Finish Options:

  • 3K Carbon Weave

  • Forged Carbon Pattern

Reference Weight: Approximately 20.5g

Charging Power Source Support: Compatible PD / QC power sources according to the supplier

Internal Protection:

  • Overcharge protection

  • Over-discharge protection

  • Overcurrent protection

  • High-temperature protection

  • Low-temperature protection

Moisture Protection Design:

  • Rear-derailleur interface sealing

  • Internally potted electronics

  • Protocol-controlled USB-C power activation

COMPATIBILITY

Designed for compatible SRAM AXS / eTap rear derailleurs using this style of removable battery interface.

Because SRAM produces multiple generations and component variations, compatibility should not automatically be assumed across every SRAM AXS / eTap component.

Please confirm your exact rear derailleur model before ordering.

If you are unsure about compatibility, please contact us and provide:

  • Your exact SRAM derailleur model

  • A photo of the derailleur

  • A photo of the original battery mounting area

We can help confirm compatibility before purchase.

Aftermarket Product Notice

This is an aftermarket replacement battery and is not an original SRAM product.

SRAM, AXS and eTap are trademarks of their respective owners and are used only to identify the intended compatibility and application of this product.

FREQUENTLY ASKED QUESTIONS

Do I need a separate charging cradle?

No.

The battery has a built-in USB-C charging port, so it can be charged directly using a compatible USB-C cable and power source.

What capacity is available?

This version is currently available in 300mAh.

How much does the battery weigh?

The pictured sample weighs approximately 20.5g.

Actual weight may vary slightly due to carbon finish and production tolerances.

What is the difference between 3K Carbon and Forged Carbon?

Both versions have the same listed 300mAh battery capacity.

The difference is primarily appearance.

3K Carbon Weave features a regular woven carbon pattern.

Forged Carbon Pattern features a more irregular and distinctive carbon appearance.

Can I use a PD or QC charger?

According to the supplier, compatible PD and QC power sources are supported.

Actual charging performance depends on the charger, cable, and battery charging system.

Compatibility with every charger and cable combination cannot be guaranteed.

How is the USB-C port protected from water?

When installed, the battery uses the rear derailleur interface as part of the external sealing structure, with the sealing gasket located on the derailleur side.

Inside the battery, the charging circuitry and USB-C interface area are additionally sealed using protective potting compound.

Will the USB-C port short circuit if water enters it?

The USB-C charging interface uses protocol-controlled power activation.

The port is not continuously powered and only becomes electrically active after a compatible charging protocol has been successfully detected.

This design helps reduce the risk of a short circuit if moisture enters the USB-C port during riding.

However, the product should not be treated as completely waterproof, and the charging port should always be kept as clean and dry as possible.

Can I leave the battery installed while charging?

Yes, the integrated USB-C port is designed to make direct charging more convenient.

Make sure the charging area is clean and dry before connecting the USB-C cable.

Is this an original SRAM battery?

No.

This is an aftermarket replacement battery designed for compatible SRAM AXS / eTap applications.

Important Usage Notes

Before charging, check that the USB-C port is clean and dry.

Do not charge the battery if:

  • The charging port is visibly wet

  • The battery housing is damaged

  • The battery is swollen

  • The USB-C connector is damaged

  • The battery has been involved in a severe impact

Do not disassemble, puncture, crush, burn, or modify the battery.

Use a compatible, good-quality charging cable and power source.

If abnormal heat, swelling, odor, smoke, or charging behavior occurs, stop using the battery immediately.