Battery packs, hub motors, mid-drive systems, controllers, and error codes — the engineering data that e-bike brands don't print on the product page.
Voltage, capacity, cell chemistry, and BMS features — the four parameters that determine range, longevity, and safety.
Scroll horizontally on mobile. OEM battery specs cross-checked against manufacturer service documents.
| Battery Model | Voltage | Capacity (Wh) | Chemistry | Cell Count | Weight (kg) | Nominal Cycles | Compatible Brand | Price (USD) |
|---|---|---|---|---|---|---|---|---|
| Bosch PowerTube 625 | 36V | 625 Wh | Li-ion (18650) | 40 | 3.8 kg | 500-700 | Bosch e-bike systems | $850 |
| Bosch PowerPack 500 | 36V | 500 Wh | Li-ion (18650) | 32 | 3.1 kg | 500-700 | Bosch e-bike systems | $680 |
| Shimano STEPS BT-E8035 630Wh | 36V | 630 Wh | Li-ion (21700) | 40 | 3.9 kg | 600-800 | Shimano STEPS EP8 / E7000 | $820 |
| Specialized Turbo Levo (Internal 700Wh) | 36V | 700 Wh | Li-ion (21700) | 48 | 4.3 kg | 600-800 | Specialized Brose Drive | $950 |
| Generic 48V 14Ah (Amazon / Aftermarket) | 48V | 672 Wh | Li-ion (18650 — variable quality) | 52 (13S4P) | 4.5 kg | 300-500 | Generic hub motor kits | $280-$450 |
| Rad Power Bikes 672Wh | 48V | 672 Wh | Li-ion (18650) | 52 (13S4P) | 4.2 kg | 400-600 | RadRunner / RadCity / RadExpand | $599 |
| VanMoof S5 478Wh | 36V | 478 Wh | Li-ion (21700 integrated) | Integrated pack | 3.2 kg (pack only) | 600-800 | VanMoof S5 / A5 | $799 |
Torque vs wattage: why two motors with the same nominal wattage can deliver wildly different ride experiences.
Hub motors sit inside the wheel hub — typically the rear wheel on modern bikes. They're mechanically simple, low-maintenance, and produce impressive straight-line speed. However, weight distribution shifts to the rear, and climbing performance is limited by the lack of mechanical advantage through the drivetrain.
Mid-drive motors mount at the bottom bracket and drive through the chain. This means the motor leverages the bike's gear range — critical for climbing steep terrain. Mid-drives deliver better weight distribution but require more sophisticated torque sensing and have more mechanical wear points.
Two motors with identical nominal wattage (the continuous power they can sustain) can have vastly different torque figures (rotational force). Torque determines:
Nominal vs peak power, torque, support modes, and drive-unit pricing.
| Motor Model | Type | Nominal Power (W) | Peak Power (W) | Max Torque (Nm) | Support Modes | Weight (kg) | Drive Unit Price |
|---|---|---|---|---|---|---|---|
| Bosch Performance Line CX Gen 4 | Mid-drive | 250W | ~600W | 85 Nm | Eco / Tour / Sport / Turbo + eMTB | 2.9 kg | $750+ OEM |
| Bosch Cargo Line | Mid-drive | 250W | ~600W | 100 Nm | Cargo-specific modes | 3.1 kg | $850+ OEM |
| Shimano STEPS EP8 | Mid-drive | 250W | ~500W | 85 Nm | Eco / Trail / Boost / Walk | 2.6 kg | $700+ OEM |
| Brose Drive S Mag | Mid-drive | 250W | ~530W | 90 Nm | Eco / Sport / Tour / Boost | 2.9 kg | $720+ OEM |
| Bafang M620 Ultra (Mid-drive) | Mid-drive | 1,000W | 1,500W+ | 160 Nm | 5-level assist + throttle | 5.5 kg | $450 (aftermarket kit) |
| Generic Rear Hub Motor 500W | Rear Hub | 500W | ~750W | 55 Nm | 5-level pedal assist + throttle | 3.5 kg | $220 (kit) |
| Generic Front Hub Motor 250W | Front Hub | 250W | ~350W | 35 Nm | 3-level assist | 2.8 kg | $150 (kit) |
Battery capacity is only half the story — rider weight, terrain, and assist level are equally important.
Typical efficiency figures:
| Battery Size | Flat / Low Assist | Rolling Hills | Steep / High Assist |
|---|---|---|---|
| 250 Wh | 17 – 25 mi | 10 – 12 mi | 6 – 8 mi |
| 500 Wh | 33 – 50 mi | 20 – 25 mi | 12 – 17 mi |
| 625 Wh (Bosch) | 42 – 62 mi | 25 – 31 mi | 15 – 21 mi |
| 750 Wh | 50 – 75 mi | 30 – 37 mi | 18 – 25 mi |
| 1,000 Wh | 67 – 100 mi | 40 – 50 mi | 25 – 33 mi |
How long it takes to charge, how to store, and the habits that double (or halve) battery lifespan.
Generic controller faults plus brand-specific error codes from Bosch and Shimano.
E001
Critical
Throttle not producing valid voltage output. Check connector at the controller for loose or corroded pins. Verify throttle resistance across 3-wire output.
E002
Warning
Hydraulic brake sensor disconnected, misaligned, or jammed. The controller thinks brakes are applied — cuts motor power. Inspect both brake levers.
E003
Warning
Pedal Assist Sensor (PAS) not detecting rotation. Check disc/magnet alignment near bottom bracket, verify sensor gap, inspect wiring routing.
E010
Warning
Battery pack below minimum voltage threshold. One or more cells likely discharged below safe limit. Stop riding — fully charge and inspect pack.
E020
Critical
Controller MOSFET junction temperature exceeded limit. Stop riding immediately. Let cool. Verify airflow / heatsink mounting. Reduce load if climbing sustained.
E030
Critical
Motor winding temperature too high. Sustained steep climbs or stalled motor. Stop, allow to cool. Check for debris in motor housing or rubbing rotor.
E040
Warning
CAN / serial communication lost between display and controller. Check cable routing near headset for pinch points or broken wiring.
E050
Critical
Battery Management System detected an internal fault. Cell imbalance, short-circuit protection tripped, or thermal cutoff. Do not continue — inspect pack.
Error 21
Bosch
Bosch-specific: controller cannot communicate with battery. Clean contacts with isopropyl alcohol (90%+), inspect for corrosion or bent pins in the mount.
Error 504
Shimano
Shimano STEPS: display / drive unit firmware incompatible. Factory reset required via Shimano E-Tube Project app or dealer tool.
Classifications and maximum allowed power output for public road use. Local ordinances may differ.
| Region | Max Nominal Power | Speed Limit (Assisted) | Throttle Allowed? | Classification |
|---|---|---|---|---|
| United States | 750W | Class 1: 20 mph / Class 3: 28 mph | Class 1: No / Class 2: Yes, 20 mph / Class 3: No | 3-class system (varies by state) |
| European Union | 250W | 25 km/h (15.5 mph) | Only below 6 km/h "walk assist" | EN 15194 standard — pedelec only |
| United Kingdom | 250W | 25 km/h (15.5 mph) | Same as EU — pedelec only | Same as EU standard |
| Canada | 500W | 32 km/h (20 mph) | Yes (province-dependent) | Provincial regulations vary |
| Australia | 250W | 25 km/h | Pedelec only in most states | State-specific; Victoria allows 250W throttle |
From lightweight commuters to high-performance extreme models — check local legality before purchasing anything above 1,000W.
| Model | Motor Power | Top Speed | Real Range | Battery | Weight | Use Case | Approx. Price (USD) |
|---|---|---|---|---|---|---|---|
| Razor E300 | 250W | 15 mph | 40 min / ~6-8 mi | 24V 7.8 Ah lead-acid | 27 kg | Lightweight commuter / teen use | $280 |
| Segway Ninebot Max G30LP | 350W (peak 700W) | 18.6 mph | 25 miles | 36V 10.2 Ah Li-ion | 19.5 kg | Commuter / campus | $799 |
| Apollo Explore | 1,000W (peak 1,400W) | 31 mph | 34 miles | 48V 18.2 Ah Li-ion | 31 kg | Performance commuter / hills | $1,499 |
| NAMI Burn-E 2 Max | 2,000W (peak 3,600W) | 60 mph | 70 miles | 60V 30 Ah Li-ion | 53 kg | Extreme performance — NOT legal on public roads in most regions | $3,299 |
Always verify local e-bike classification. Higher-wattage unclassified e-bikes may be illegal on public roads. Helmet laws apply in most jurisdictions and are strongly recommended regardless.
Battery fires from damaged lithium-ion packs are extremely rare but documented. Never charge a visibly swollen or damaged battery. Always charge on a non-flammable surface and never leave a damaged pack unattended while charging.
When inspecting used e-bikes, pay particular attention to: (1) pack swelling, (2) cut or frayed wiring near the battery mount, (3) evidence of water damage or corrosion on contacts, and (4) abnormal thermal behavior during a short test ride.