BecSpec Because specs matter.
Free e-bike battery compatibility checker
E-bike battery compatibility

What are you trying to do?

Choose replacement, capacity upgrade or extra range first. Then enter the battery or bike details you know. BecSpec checks the manufacturer-documented route rather than assuming batteries work together because the voltage or plug looks right.

Before you buy or fit anything: voltage, capacity, connector shape and physical fit do not prove compatibility by themselves. This checker tells you what the manufacturer evidence supports and what still needs checking.

Battery-first works well for Shimano, Giant, FAZUA and MAHLE. Bike-first paths also cover selected Specialized, Trek, Santa Cruz and SCOTT models.

For some bikes the year, frame size or drive-unit generation changes the answer, so include those details if you know them.

Needed where Shimano has more than one holder family.

Useful where the manufacturer changed hardware between model years.

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Major brands and bike systems

Brand-neutral compatibility, not a shop catalogue

BecSpec compares documented compatibility across the brands and bike systems it can support with primary evidence. Coverage is deliberately uneven: a brand is only included where the battery identity and compatibility relationship can be established without guessing. Unsupported models stay unconfirmed rather than being steered toward a preferred replacement.

Common compatibility questions

Battery guides

Trek Fuel EXe: 360Wh vs larger internal batteryWhy the 360Wh-only rule is explicit.Heckler EP8 vs EP801 batteryWhy drive-unit generation changes the service path.FAZUA ENERGY 430 → 480What FAZUA documents for the capacity upgrade.MAHLE iX250 → iX350Shared fitting points, dealer activation required.Trek 600Wh vs 800WhRail+ and Powerfly+ bike-specific rules.SCOTT range extender compatibilityExtra range is different from replacing the main battery.Giant EnergyPak Smart 800 Cover BWhy exact bike, model year and market matter.
Before you buy

What changes the battery answer?

System generation matters. A battery that belongs to the same brand or nominal voltage can still use a different mount, communications system, BMS relationship or charger. Keep exact battery identity and drive-system generation together.

The bike can be the limiting part. Model year, frame integration and the bicycle manufacturer's service instructions can make a battery route bike-specific even when the battery manufacturer documents a broader technical relationship.

A larger capacity is not automatically an upgrade. Some systems have an evidenced larger-battery path; others require a different mount, dealer activation or bicycle-OEM approval. Start with the exact battery and bike rather than assuming more watt-hours means compatible.

Chargers and service steps matter too. Where documentation names a charger, firmware, activation or authorised-dealer step, BecSpec keeps that condition attached to the result instead of reducing the answer to physical fit.

Can I use a larger e-bike battery? · How battery matching works · Data sources · Limits of the finder