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Match voltage, current and frame space first — capacity and price come after. Three families, every pack with named cells, a matched charger and a quick-release mount.
Every pack ships with its matched charger and mounting kit. Prices, voltages and stock live on the product cards — the guide below helps you pick between them.
Read the voltage on the controller, confirm the maximum input it accepts, then pick its card. Full-charge voltage is listed because that is the figure that catches people out.
| System | Full charge | Typical kit | Options | Energy | Published range |
|---|---|---|---|---|---|
| 36V | 42V | 250W–750W | Entry XS 15Ah | 540 Wh | 30–50 km (19–31 mi) |
| 48V | 54.6V | 500W–1,500W | Entry 16/20Ah · Taishan 30Ah | 768–1,440 Wh | 30–80 km (19–50 mi) |
| 52V | 58.8V | 500W–3,000W | Entry 20Ah · Taishan 25Ah · HS-II 30Ah | 1,040–1,560 Wh | 35–85 km (22–53 mi) |
| 60V | 71.4V | 2,000W–3,000W | Taishan · HS-II 20Ah | 1,260 Wh | 40–55 km (25–34 mi) |
| 72V | 84V | 3,000W–4,000W | Taishan · HS-II 20Ah | 1,440 Wh | 30–40 km (19–25 mi) |
Higher voltage buys performance, not distance — range bands are the manufacturer's figures for the motor class shown.
Three families, three different problems solved.
Best for: commuters, flat routes, budget builds.
Best for: most conversions — its shallow wedge clears frames taller packs cannot.
Best for: long distance, delivery and hills — needs a deeper triangle.
A worked example. A 90 kg rider on a 52V 2,000W kit, hills, 40 km a day → HS-II 52V 30Ah. The same rider on flat 15 km commutes → Taishan 48V 30Ah or Entry 52V.
The highest price in the range is only the right answer when your riding earns it.
| Field | Entry Down-Tube | Taishan | HS-II |
|---|---|---|---|
| Voltages | 36V, 48V, 52V | 48V, 52V, 60V, 72V | 52V, 60V, 72V |
| Capacity | 540–1,040 Wh | 1,260–1,440 Wh | 1,260–1,560 Wh |
| Cells | LG 21700 / EVE by model | LG 21700 · Samsung 50S on 72V | LG 21700 · Samsung 50S on 72V |
| BMS continuous | 30A / 40A | 60A | 60A |
| Charge time | 7–10 h | 4–6 h | 4–5 h |
| Cycle life | 800–1,000 | 800–1,000 | 800–1,000 |
| Connector | XT60 | XT60 (48/52V) · XT90 (60/72V) | XT60 (52V) · XT90 (60/72V) |
| Mounting | Down tube | Frame triangle, low profile | Frame triangle, deeper |
| Advantage | Lightest, lowest cost | Fits the most frames at 60A | Most energy on board |
| Trade-off | Lower current, slow charging | Costs more than Entry | Largest and heaviest |
Specifications vary by the variant you select — treat product-page variant data as the final ordering reference.
Motor wattage is a category. The controller decides what the battery must deliver — so answer these four, in order, and the shortlist is usually two packs.
What nominal voltage does the controller run — and what maximum input does it accept at full charge?
What continuous current will it pull at full throttle? The BMS must meet it with margin.
How much frame room is left once the rail, connector and slide-off travel are counted?
Only now — how many watt-hours does your daily distance actually need?
Factory bikes commonly run 24V, 36V or 48V. Conversions go further — and 52V batteries improve hill performance and acceleration over a 48V pack of the same amp-hours, felt on every steep climb.
Legality, because it is often confused: UK road-legal status is decided by the motor's continuous rated power and assisted speed — not battery voltage.
LG 21700, Samsung 50S 21700 on 72V, EVE on specified Entry models — checkable, not claimed.
Every Taishan and HS-II pack feeds a high-current controller without sagging.
Output matched to the pack it ships with — part of the system, not an accessory.
Covered ports, power display, IP65 on specified packs, quick-release mount in four steps.
A 52V pack reaches 58.8V off the charger — a 48V-only controller may not survive it. If the label lists one voltage and your pack charges above it, it is not safe.
Continuous rating must meet the controller's maximum current with margin: 60A on Taishan and HS-II, 30A/40A on Entry. Peak figures are an allowance, not a budget.
XT60 on 36–52V, XT90 on 60/72V. Confirm the low-voltage cutoff, and pair the pack with the Smart eBike Controller with App Programmable Settings rather than choosing them in sequence.
Fit is three-dimensional: add the rail, the connector and the slide-off travel to your measurements. If the pack fits but cannot be removed, it does not fit.
| Position | Advantages | Limitations | Suits |
|---|---|---|---|
| Frame triangle | Better protection and aesthetics — weight low and central, best handling, largest capacities | Needs a clear triangle: both packs are 97 mm thick, so height decides — Taishan's 157.4 mm wedge vs HS-II's 195.4 / 281.3 mm uprights | Taishan · HS-II |
| Down tube | Familiar, low centre of gravity, easy to reach | Limited by bottle-boss spacing and the ≈368 mm case | Entry packs |
| Rear rack | Frees the frame — suits small and step-through frames | Weight high and rearward; can affect handling on heavily loaded bikes | Small frames, folders |
Not sure?Send a side-on frame photo with measurements — we confirm the combination in writing before you order.
One-year warranty, regional support.
Free full-system and battery repair service in the UK, free battery repair service in the US and Netherlands, and manufacturing-defect cover worldwide—all backed by secure, tracked delivery.
Cell quality decides a battery, and it is the hardest thing to see from outside — which is why so much battery marketing is adjectives. KirbEbike names the cell instead, and whether Samsung cells or LG suit better depends on the job, not the badge.
A good battery retains around 60% capacity after 1,000 charge cycles; these packs are rated 800–1,000 cycles — three to five years of commuting before range drops noticeably.
The BMS monitors voltage, current and temperature and disconnects on a fault. Around it, the battery cover does the quiet work: IP65 sealing on specified packs and a quick-release mount that fits in four steps.
Read the controller label, not the motor. It states the nominal system voltage and often a maximum input voltage. Match the nominal figure first, then confirm the controller accepts the pack's full-charge voltage: 42V for 36V packs, 54.6V for 48V, 58.8V for 52V, 71.4V for 60V and 84V for 72V. If the controller lists only one voltage and your pack charges above it, that combination is not safe.
Amp-hours measure charge capacity and only compare fairly at the same voltage. Watt-hours measure stored energy and compare across voltages: nominal voltage multiplied by amp-hours. A 48V 20Ah pack is about 960 Wh, while a 52V 20Ah pack is about 1,040 Wh. Use watt-hours whenever you are comparing packs of different voltages.
It depends on how quickly you use the energy. Divide usable watt-hours by your consumption per kilometre: gentle assisted riding on the flat can approach 20 Wh/km, while hard riding on hills can exceed 30 Wh/km. Motor power, controller current, speed, rider and cargo weight, gradient, tyre pressure, temperature and assistance level all change the result. Published range bands assume a motor class rather than promising a distance.
A 350 Wh battery is sufficient for flat urban routes, but batteries over 350 Wh are recommended for hilly terrain because climbing pulls far more current than cruising. For repeated steep climbs, a heavier rider, or cargo, start at 1,000 Wh and upwards. A 52V system also improves hill performance and acceleration over a 48V pack of the same amp-hour rating, so voltage and capacity should be chosen together.
On the Taishan and HS-II packs, about four hours for a 20Ah pack, around five hours for 25Ah to 30Ah, and about six hours for the 48V 30Ah pack. Entry Down-Tube models ship with a lower-output charger and take seven to ten hours. Fast charging is a system property, so always use the charger supplied with the pack.
Measure the usable space in three dimensions, then add the mounting rail, the connector and the room needed to slide the pack off. Taishan and HS-II are both 97 mm thick, so height is usually what decides it: Taishan is a shallow wedge at 157.4 mm, while HS-II rises to 195.4 mm and 281.3 mm on its upright edges. That is why Taishan clears frames the HS-II cannot. If you are unsure, send a side-on frame photograph with measurements and we will confirm before you order.
Both are established manufacturers, and the more useful question is which cell suits the job. KirbEbike uses LG 21700 cells across most models and Samsung 50S 21700 cells in the 72V packs, where sustained high-current output matters most. What matters more than the brand is that the cell is named, and that the BMS and charger are matched to it.
These packs are rated at 800 to 1,000 full charge cycles by model, and a good battery can retain around 60% of its original capacity after 1,000 cycles. For most riders that is three to five years of regular commuting before range drops noticeably. Avoiding deep discharges below 20%, storing the pack at around 20–25°C and using the matched charger all extend that.
Still deciding between two batteries? Send your controller details and a frame photograph and we will confirm the match before you order.
Building rather than replacing? Start from the 52V 2000W MTX Rim Ebike Conversion Kit Waterproof Design or browse the full collection below.
