Replacement batteries for e-motorcycles:dimensions are the one thing you cannot guess
The short answer: size a replacement pack from the bay on your own vehicle, not from a capacity table. Measure the clear internal length × width × height, including the space taken by connectors, handle and lock — not the outer frame. At the same time confirm connector polarity and whether the BMS handshakes. A matching bay and voltage drops straight in; when a larger capacity will not physically fit, there are only three routes — modify the bay, split the pack, or change the vehicle.
verifiedDimensions and capacity are confirmed against your measured bay; UN38.3, MSDS and the dangerous-goods packing certificate travel with every container.
Four measurements, all done at the vehicle before ordering
- 01straighten
Measure the clear internal space, not the outer frame
Take the smallest internal clearance from wall to wall (length × width × height). The outer frame includes folded edges and reinforcement plates and is typically 20 – 40mm larger, which is the most common reason an order fails. Take the reading at the narrowest point in each direction and check point by point where the bay has angles or ribs.
Record: L × W × H at the narrowest point - 02inventory_2
Deduct harness bend radius and damping allowance
Allow for the harness bend radius and the damping foam: a removable structure needs 8 – 12mm clearance all round with high-damping EVA foam so nothing touches hard, and a fixed bay still needs room for the harness to bend without the insulation wearing through under vibration. Note the handle, lock body and connector positions separately.
Record: tolerance, foam thickness, accessory space - 03cable
Identify the connector type and polarity
Check the positive, negative and signal definitions pin by pin. Lithium harnesses and the factory lead-acid loom are frequently ordered differently, and reverse connection destroys both the BMS and the controller. Record the connector model and current rating too: power terminals are selected against continuous discharge current (150 – 250A at platform level, 3C peak for short climbs).
Record: terminal model, polarity, signal definitions - 04hub
Confirm whether the BMS will handshake
If the cluster reads SOC from the original BMS, confirm protocol and baud rate. Without a handshake the state of charge may not display, the vehicle may raise a fault, or it may refuse to power up. Send the cluster model and a CAN capture: most common protocols already have a matching BMS build, and an unusual protocol can be met with custom firmware.
Record: cluster model, protocol, baud rate
Work back from the bay: six common bay ranges
Once the clear space is measured, locate the bay range below for a first indication, then fix the capacity step from payload and daily distance. A matching bay and voltage drops straight in; a voltage change also needs the controller MOSFET rating and cluster input range checked.
| Bay L × W × H (range) | Typical vehicle and duty | Voltage platform | Capacity combinations | Pack weight (typical) | Reference pack model |
|---|---|---|---|---|---|
| ≈ 320–380 × 230–290 × 200–250 mm | Delivery e-motorcycle / swap two-wheeler, high turnover | 60V (16S LFP) | 60V 50 – 60Ah | ≈ 21 – 25 kg | VT-6050-LFP-SWAP |
| ≈ 330–400 × 220–280 × 200–260 mm | High-speed e-motorcycle, long-distance commuting | 72V (24S LFP) | 72V 40 – 60Ah | ≈ 22 – 32 kg | VT-7240-EMOTO · VT-7260-SWAP |
| ≈ 420–520 × 300–360 × 240–300 mm | Passenger e-rickshaw, 4–5 passengers | 48V / 51.2V (16S) | 51.2V 100 – 120Ah | ≈ 36 – 43 kg | VT-48100-AIS156-MAX |
| ≈ 480–580 × 320–380 × 260–320 mm | African passenger tricycle, hot and heavily loaded, unpaved roads | 60V / 72V platform | 60V / 72V 120 – 140Ah | ≈ 64 – 75 kg (72V) | VT-72130-TROPICAL-HD |
| ≈ 520–620 × 360–420 × 280–340 mm | Heavy cargo tricycle, 800 – 1000 kg rated payload | 72V (24S LFP) | 72V 160 – 200Ah | ≈ 86 – 107 kg | VT-72180-CARGO-PRO · VT-72200-CARGO-MAX |
| ≈ 460–560 × 300–360 × 240–300 mm | Resort golf cart / site shuttle | 48V / 72V platform | 48V 105 – 150Ah | ≈ 35 – 50 kg | VT-48105-GC-CANBUS |
These are the common ranges for each vehicle class, and the same model varies between body builders and batches — your measured clear dimensions govern. Pack weight assumes steel enclosure, BMS and harness at roughly 7 kg/kWh (±5%). For the capacity and range basis see the real capacity and range guide.
Specification notice:The figures above are engineering reference values. They may differ with production batch, configuration and actual duty cycle, and the percentages for life, efficiency, availability and coverage are engineering estimates and bench references. Contact us for the detailed specification sheet.
The limit on capacity: three routes when the bay is too small
If the capacity you want will not fit, pressing the pack in is not a solution. Pack volume is set by total energy (kWh = V × Ah), so more capacity always means more volume. Work out how many millimetres short you are and in which direction, then pick one of the three routes below.
- Modify the bay: enlarge or deepen the bay in the frame, adding a reinforcement plate and new fixing points at the same time. Suited to frames with some margin, where the work is done by a professional workshop.
- Split the installation: divide one large pack into two (under-seat plus under-floor, or two parallel packs) managed by one BMS architecture. More complex routing, but more total energy without touching the frame.
- Change the vehicle: when neither the bay nor the frame has margin and the payload has been exceeding the original design, a vehicle with a better-matched bay usually costs less than repeated modification.
- Stay one step lower: if the daily distance is genuinely within 70 – 120km, keep the capacity that fits and replace at the same voltage — the extra weight you avoid would have eaten part of the range it was meant to add.
The five questions we are asked most about replacement sizing
How do I know which size replacement battery to buy?expand_more
The bay is only a few millimetres short — can I force it in?expand_more
How many insertions can a replacement pack connector take?expand_more
Is a bigger capacity always better value?expand_more
If the size and voltage both match, does it drop straight in?expand_more
Bay measured, capacity fixed — read these three next
Replacement battery and bay lookup hub
The full bay-range table plus handles, locks and connectors on a removable module, and the pre-replacement checklist.
See replacement optionsarrow_forward48V LiFePO4 battery packs
The 16S (51.2V nominal / 58.4V full charge) capacity matrix for light passenger duty, including the swap-cabinet build.
See the 48V platformarrow_forwardTwo-wheeler power and swap
Complete packs for high-turnover delivery and swap operation: lift-out structure, BMS protocol adaptation and fleet delivery.
See the two-wheeler platformarrow_forwardSend your bay dimensions and we will quote a pack that fits
Give us the bay length × width × height, the vehicle voltage platform, payload, daily distance and motor rating, and we will return the replacement selection, FOB / CIF pricing, container allocation and the shipping document list.
- Selection advice and pricing within 24 hours on working days
- Sample packs available to prove fit and duty cycle before committing to a container
- Vehicle parameters and market-access documents are strictly confidential; NDA available first
Specification notice:The figures above are engineering reference values. They may differ with production batch, configuration and actual duty cycle, and the percentages for life, efficiency, availability and coverage are engineering estimates and bench references. Contact us for the detailed specification sheet.