E-Bike Battery Specs Decoded: Volts, Amp-Hours and Dual Batteries

Volts x amp-hours = watt-hours: the only range math that matters

When a distributor asks how far an e-bike will go, the honest answer starts with one multiplication. Volts (V) multiplied by amp-hours (Ah) equals watt-hours (Wh) — the total energy stored in the pack. A 48V 15Ah battery holds 720Wh. A 48V 25Ah pack holds 1,200Wh. A 52V 20Ah pack holds 1,040Wh, and two of them in parallel give you 2,080Wh.

Watt-hours are the only figure that lets you compare packs of different voltages on equal terms. A 48V 20Ah battery (960Wh) carries more energy than a 52V 15Ah battery (780Wh), even though the second number looks bigger on a spec sheet. Buyers who quote only amp-hours in their product listings are inviting returns, because riders judge range in miles, and miles track watt-hours far more closely than either number alone.

Watt-hours are the first filter for comparing packs. The Smart commuter, with a 48V 20Ah pack, is rated at 38 miles of range, while the Monster dual-battery fat tire, running 52V 20Ah ×2, is rated at the 100+ mile level.

Reading a spec sheet without getting fooled

Nominal vs. charge voltage: ask for the chemistry-specific charger output voltage and confirm controller compatibility.
Ah at what voltage? A supplier quoting "20Ah" without a voltage is quoting half a spec.
Continuous vs. peak discharge: the BMS and cells must sustain the controller's continuous draw, not just its peak.
Usable vs. nominal capacity: most manufacturers rate packs at 100% depth of discharge; real-world riding rarely goes there.

48V vs 52V vs 72V systems

Voltage sets the character of the bike. It determines wiring requirements and which controllers and displays are available off the shelf.

48V is the global default for pedal-assist platforms. It covers everything from a 500W Bafang on the FT-09 (48V 15Ah) to the 1,000W Bafang G510 mid-drive on the Ranger low-step (48V 20Ah) to the M-08 mid-fat with a 48V 25Ah pack.

52V is the enthusiast and performance tier. It is not a standard nominal voltage in most pedal-assist regulations, so it usually appears on bikes positioned as off-road, high-torque, or dual-battery machines. Lantu's FT-014 runs a 52V system with a 1,200W motor, and the Monster pairs two 52V 20Ah packs to feed a 1,500W motor. If your brand sells into the performance or fat-tire segment, 52V is where the margin lives.

72V belongs to the moped and light-motorcycle category, not to pedal-assist bicycles. It appears in two forms on our line: the September 1500W moped with a 72V 32Ah lead-acid pack (about 60 km/h top speed, roughly 80 km range) and the Revenge Plus with a 72V 40Ah lithium pack (110 km/h / 68 mph, EEC certified, TFT display). The chemistry choice matters enormously here — lead-acid is heavy and cheap to land, lithium is light and expensive but delivers far more usable cycles. For 72V products, confirm with your buyer whether they want a moped registration path or a motorcycle one, because the battery choice follows the homologation route.

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Dual-battery systems: when they pay off

A dual-battery bike is not simply a bike with more range. It is a different product with different buyers, different logistics, and different failure modes. Understanding when the extra pack earns its cost is one of the most useful judgments an OEM buyer can make.

When dual batteries pay off:

Long-range positioning. Two 52V 20Ah packs store 2,080Wh nominal. If your brand competes on range, ask for measured range data for the configuration.
Delivery and commercial fleets. A rider doing eight-hour shifts cannot afford to stop and charge. Two packs, or one large pack plus a hot-swap spare, keeps the vehicle earning.
High-draw motors. Splitting the load across two packs lowers per-pack discharge current. Request pack-level test evidence for cycle-life claims.
Premium price anchoring. A dual-battery model gives your line a flagship. The Alibaba-listed dual-battery bike is priced at $1,499–$1,649.

When they don't:

If your market is 20 mph commuters doing under 15 miles a day, a single 48V 20Ah pack is enough, lighter, and cheaper.
If frame real estate is tight, forcing two packs into a small triangle creates service problems and ugly cable routing.
If your dealer network cannot explain parallel vs. sequential discharge, support tickets will eat the margin.

Parallel vs. sequential: decide before you order

In a parallel configuration, both packs discharge together, sharing current. In a sequential setup, the rider drains one pack, then switches to the other. Confirm the actual architecture for the model you plan to order and request test evidence.

Removable vs integrated packs

This is a packaging and market question more than a technical one. Both approaches use the same cells; they differ in how the pack mounts and who can service it.

Removable packs slide out of a frame mount or rear rack and can be charged indoors, swapped, or replaced without a shop visit. They are the default for delivery fleets, for markets with cold winters where riders store batteries at room temperature, and for any brand whose dealers want to sell a spare battery as an accessory. Confirm each model's battery mounting and removal method with the factory. For a deeper look at mount types and locking mechanisms, see our [removable battery guide](/blog/removable-battery-guide/).

Integrated packs sit inside the downtube. They look cleaner and allow a more sculpted frame. Integrated appearance does not always mean non-removable — confirm the removal method for each model.

Battery safety and certifications buyers should request

Battery safety is where a cheap supplier becomes an expensive mistake. The cells, the BMS, the wiring gauge, the fuse, the charger, and the enclosure all have to work as a system. Buyers sourcing from China should ask for documentation on each of the following.

Certifications and standards to request:

CE for the European market
EN15194 for pedal-assist bicycles sold in the EU
RoHS for restricted substances in the pack and electronics
CPSC for the US market
EEC where the product is homologated as a moped or motorcycle — our Revenge and Revenge Plus models carry EEC certification

Certificates available upon request; ask for the documents directly and verify them against the issuing lab. Any supplier who cannot produce a certificate on request is a supplier to walk away from. Lantu's certificates are available upon request.

Beyond the certificate, ask for:

Cell brand and model, plus whether cells are grade A or a lower tier.
BMS specification: continuous and peak discharge current, over-current, over-voltage, under-voltage, and temperature cutoffs.
Pack-level test reports: overcharge, short circuit, drop, vibration, thermal cycling.
Charger compliance: the charger is part of the safety system and is often the cheapest component in the box.
UN 38.3 transport test summary — request the transport-test documentation and separately verify packaging requirements.

Enclosure quality matters too. Our frames go through internal and external galvanizing plus a special anti-rust coating, and every bike and accessory is tested by our QC team — but the pack itself deserves its own line-item inspection on your PO, not just a pass/fail on the finished bike.

Specifying batteries in OEM orders

Most sourcing failures are specification failures, not manufacturing failures. A battery spec that says "48V 20Ah" leaves a dozen decisions open, and the factory will make them for you — reasonably, but not necessarily in your interest.

Specify at least these fields:

1. Nominal voltage and capacity in Ah (state both, always together)
2. Chemistry (li-ion or lead-acid; for li-ion, cell format and brand tier)
3. Continuous and peak discharge current the BMS must support
4. Charger output voltage and current, plus charge time target
5. Mount type and interface (integrated, downtube slide, rear rack, dual)
6. Lock and key system, if removable
7. Connector type and pinout
8. Operating temperature range
9. Cycle life target and capacity retention threshold
10. Certification set required for the destination market
11. Labeling: your logo, voltage, capacity, warnings, in the destination language
12. Packaging: individual carton, UN 38.3 compliant transport packaging

Two more commercial points. First, MOQ: our Alibaba-listed top products start at 10 units, which lets you validate a battery configuration on a small order before committing to a container. Second, lead time: industry-typical values are 7–15 days for samples and 30–45 days for production runs, depending on configuration and season — confirm against your specific build before you promise dates to your dealers.

Because battery, motor, and display are among the twelve customizable items on our platform, the cleanest way to order is to give us the destination market, the target retail price, and the range claim you want to make. The battery spec falls out of those three inputs. If your product line is built around long-range positioning, our [long-range electric bikes](/long-range-electric-bikes/) overview shows how pack size and motor choice combine across real builds.

FAQ

What do "48V 20Ah" and "52V 20Ah" actually mean for range?

They store different amounts of energy. 48V × 20Ah = 960Wh; 52V × 20Ah = 1,040Wh. The 52V pack carries about 8% more energy, but the two are much closer in range than the voltage difference suggests. Always compare watt-hours, not amp-hours.

Can I run two batteries of different voltages or capacities together?

No. Parallel dual-battery setups require matched voltage, chemistry, and ideally matched capacity and age. Mixing an old pack with a new one, or a 48V with a 52V, risks current flowing from one pack into the other and damaging both. If you want a spare, buy it matched and rotate the packs.

Why does Lantu offer a 72V lead-acid moped alongside 72V lithium models?

Because the two serve different buyers. Lead-acid is heavier and cheaper to land, suited to price-sensitive moped markets; the 72V 40Ah lithium pack on the Revenge Plus supports 110 km/h and EEC homologation. The right choice depends on whether your market registers the vehicle as a moped or a motorcycle, and on how much the buyer cares about weight.

Are dual-battery bikes legal where I sell?

It depends on the market and how the bike is classified. Request destination-specific classification before ordering, and ask us for the certification set that matches it.

What certifications should I ask for on a battery pack?

Request the pack-specific documentation applicable to your destination market, including transport-test documentation. Ask for the actual certificates and verify the issuing lab — a claim on a website is not a certificate.

What is the MOQ and lead time for a custom battery configuration?

Our listed top products start at 10 units, so you can validate a configuration on a small run. Industry-typical lead times are 7–15 days for samples and 30–45 days for bulk production. Confirm both against your specific build before committing to dealer delivery dates.

Ready to lock down the battery spec for your next model? Send us your destination market, target retail price, and the range claim you want to make — [request a quote](/contact/) and we will respond to your inquiry within 24 hours.