Watt-hours (Wh) — not amp-hours (Ah) — tell you how far an e-bike battery will actually take you. Watt-hours measure the total energy stored in the pack, and you work them out with one simple sum: watt-hours = volts × amp-hours. The 48V 25Ah battery on the Cyberbikes Centauro, for example, holds 48 × 25 = 1,200Wh. Amp-hours on their own only tell half the story because they ignore voltage. So if you remember one thing from this guide, make it this: compare e-bike batteries by watt-hours, and everything else falls into place.
At Cyberbikes in Leichhardt we get asked this almost every week — “is a 20Ah battery better than a 15Ah one?” The honest answer is “it depends on the voltage.” Below we break it down using engineering references from Grin Technologies’ ebikes.ca resources and real specs from the electric bikes we sell here in Sydney.
What amp-hours and volts actually measure
Think of your battery like a water tank. Volts (V) are the pressure pushing the water out, amps are how fast it flows, and amp-hours (Ah) are how much charge the tank can deliver over an hour at that pressure. On their own, amp-hours describe capacity at one specific voltage — they are not a measure of energy, and energy is what moves you down the road.
Watt-hours are the real measure of stored energy, and therefore of range. As ebikes.ca puts it, the figure that matters most when comparing how far a pack will take you is not the amp-hour capacity but the total energy stored in watt-hours — and you get watt-hours by taking the actual amp-hours and multiplying by the pack voltage. Two batteries can look completely different on their labels yet deliver the same range. A 48V 25Ah pack (1,200Wh) and a 52V 23Ah pack (about 1,196Wh) are, for all practical purposes, the same size tank.
How to turn watt-hours into real-world range
Once you know the watt-hours, range becomes easy to estimate. It comes down to your consumption in watt-hours per kilometre (Wh/km) — the very number a Cycle Analyst or a good e-bike display will show you. According to ebikes.ca, most riders average around 10 Wh/km. Push hard, climb Sydney’s hills or haul a loaded cargo rack and that climbs to 12–15 Wh/km; feather the assist on the flat and it drops to 6–8 Wh/km.
Here is what that looks like for a 1,200Wh battery like the Centauro’s:
| Riding style | Consumption | Estimated range on 1,200Wh |
|---|---|---|
| Eco / light assist, flat roads | ~7 Wh/km | ~170 km |
| Typical commuting | ~10 Wh/km | ~120 km |
| Hard riding, hills or cargo | ~15 Wh/km | ~80 km |
These are estimates built on ebikes.ca’s rule of thumb, not a guarantee — real range depends on rider weight, terrain, wind, tyre pressure and temperature. It’s also worth knowing that usable range is set by the battery’s available capacity, not the nominal amp-hour figure printed on the box.
A quick reference: reading any battery label
Sellers love to quote amp-hours because a bigger number sounds better. Convert everything to watt-hours and the comparison becomes fair. Here are some common e-bike battery labels turned into watt-hours:
| Battery label | Watt-hours (V × Ah) | Rough range at 10 Wh/km |
|---|---|---|
| 36V 10Ah | 360 Wh | ~36 km |
| 36V 14Ah | 504 Wh | ~50 km |
| 48V 12Ah | 576 Wh | ~58 km |
| 48V 15Ah | 720 Wh | ~72 km |
| 48V 20Ah | 960 Wh | ~96 km |
| 48V 25Ah (Centauro) | 1,200 Wh | ~120 km |
Why you can’t compare amp-hours across different voltages
This is where amp-hours trip people up. ebikes.ca gives a clean example: a 24V 8Ah pack stores 192Wh, and a 48V 4Ah pack also stores 192Wh. Same energy, same range — even though the first has double the amp-hours. A higher-voltage battery simply needs fewer amp-hours to cover the same distance.
Flip it around and it gets sneakier. A 36V 14Ah battery (504Wh) actually holds less energy than a 48V 12Ah battery (576Wh), despite the bigger 14Ah headline. If a shop quotes only amp-hours, ask for the voltage — or better yet, ask for the watt-hours — before you compare two bikes. It’s the single fastest way to avoid overpaying for a battery that looks big but isn’t.
What this means for the Cyberbikes Centauro
The 2026 Cyberbikes Centauro runs a 48V 25Ah Samsung lithium-ion battery — a full 1,200Wh — paired with a 250W rear hub motor that is road-legal in NSW, where pedal-assist e-bikes are capped at 25 km/h. That’s a generous tank for a commuter: at a typical 10 Wh/km it’s good for roughly a week of inner-west riding between charges for many owners, with plenty of headroom for hills and a loaded rack. The battery is UL 2271-certified, and the complete bike is built to UL 2849, ISO 4210 and EN 15194 standards — the safety marks worth checking on any e-bike battery before you buy.
Want the full picture on cells, chargers and looking after your pack? Read our complete guide to e-bike batteries. And if you’ve noticed your range shrinking on cold mornings, here’s why e-bike range drops in winter. You can also see the 1,200Wh Centauro in action in our full review below.
Watt-hours also shape charging time and battery life
Watt-hours don’t just predict range — they set how long a battery takes to refill. Charging time is roughly the pack’s watt-hours divided by the charger’s power in watts. A standard 2A charger on a 48V pack delivers about 96W, so filling a 1,200Wh Centauro battery from empty takes on the order of 12 hours, while a 4A fast charger (around 192W) roughly halves that. In practice most riders never run flat, so a real top-up is far quicker — another reason a larger pack is a convenience rather than a chore.
Bigger isn’t only about distance, either. Because a 1,200Wh battery is rarely drained to empty on a short commute, each ride uses a smaller fraction of its capacity. Lithium-ion cells are happiest cycling in shallow, partial discharges, so a roomy pack you only nibble at tends to age more gently than a small one you flatten every day. That’s a quiet, long-term advantage of a high-watt-hour battery for daily inner-west commuting — you get more range today and, often, more useful years down the track.
Frequently Asked Questions
Is a higher amp-hour e-bike battery always better?
No. Amp-hours only describe capacity at a given voltage. A 48V 12Ah battery (576Wh) holds more energy — and goes further — than a 36V 14Ah battery (504Wh). Always compare watt-hours, which is volts multiplied by amp-hours.
How do I calculate the watt-hours of my e-bike battery?
Multiply the battery voltage by its amp-hours. A 48V 25Ah battery is 48 × 25 = 1,200 watt-hours. Watt-hours are the best single number for comparing how far two e-bike batteries will take you.
How many watt-hours do I need for commuting in Sydney?
At roughly 10 Wh/km, a 500Wh battery covers about 50km and a 1,200Wh battery around 120km on a charge. For most inner-west commutes of 5–15km each way, 500–750Wh is plenty; a larger pack like the Centauro’s 1,200Wh simply means fewer charges and more headroom for hills and cargo.
Does a bigger battery make an e-bike faster?
Not really. Top speed is set by the motor, controller and the law — 25 km/h for pedal-assist e-bikes in NSW. A bigger battery gives you more range, not more speed.
How long does a bigger e-bike battery take to charge?
Roughly the watt-hours divided by the charger’s wattage. A 1,200Wh battery on a typical 2-amp 48V charger (about 96W) takes around 12 hours from empty, or about half that with a 4-amp fast charger. Since you rarely charge from zero, daily top-ups are much quicker.
Want to feel 1,200 watt-hours of real-world range for yourself? Come in for a test ride at Cyberbikes, 281 Parramatta Road, Leichhardt, browse the Centauro online, or ask about our rent-to-own plans from $99.99/week.
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