KT-E09-PRO — 48V Down-Tube Battery, Four-Point Rail
The KT-E09 electrical platform on a four-fixing rail at 60mm pitch — specified when the frame carries load or the pattern is already drilled that way.
Key Details
- MOQ
- From 100 pcs
- Sample Lead Time
- 5–10 working days
- Mass Production
- 2–4 weeks after approval
- Voltage
- 48V
- Capacity Range
- 17.5–25Ah
- Form Factor
- Down-tube / shark
Cell Brands
The KT-E09-PRO exists for one reason, and it is mechanical. Electrically it is the KT-E09: the same 367.5 × 140.0 × 95.0mm shark case, the same 91-cell 13S7P 18650 build at 48V 17.5Ah, the same 65-cell 13S5P 21700 build at 48V 25Ah. What changes is the mounting rail — four fixings starting 85.4mm from the datum at 60mm pitch, against the KT-E09’s three fixings at 57mm pitch.
That fourth fixing is worth specifying when the bike carries weight. A down-tube pack is a cantilevered mass on a tube that flexes, and every removal and refit cycle works the rail. On cargo frames and delivery bikes where packs come off daily and the bike is loaded, spreading that load over four points is cheap insurance against rail wear and rattle complaints in year two.
Choosing between the two rails
If the frame is already in production, the existing drill pattern decides it — there is no engineering judgement to make. If the frame is still on the drawing board, the question is duty: daily removal, load carrying, or fleet service argue for the four-point rail; a private commuter bike does not need it.
Because the electrical platform is shared, running both rails across a product line costs one extra mechanical SKU rather than a second battery qualification. The cell block, the BMS, the UN 38.3 report and the CE Declaration of Conformity are common to both.
When the pack is the wrong size rather than the wrong rail
If 25Ah is short of the range target, the same 367.5mm case length is available 17mm taller on the 52V KT-E33 platform, which reaches 30Ah. If the frame can hide the pack instead of carrying it externally, the integrated KT-E60 covers 23Ah to 30Ah in a concealed enclosure. Down-tube versus integrated is usually settled by whether the brand wants the battery visible and swappable or hidden and clean.
Technical Specifications
| Enclosure Format | Down-tube / shark (external, removable) |
|---|---|
| 18650 Configuration | 91 cells · 13S7P · 48V 17.5Ah |
| 21700 Configuration | 65 cells · 13S5P · 48V 25Ah |
| Case Dimensions | 367.5 mm long · 140.0 mm high · 95.0 mm wide |
| 18650 Cell Block | 305.0 × 119.2 mm |
| 21700 Cell Block | 304.9 × 121.1 mm |
| Mounting Rail | 85.4 mm to first fixing, then 60.0 / 60.0 / 60.0 mm pitch (4 fixings) |
| Outputs | USB · DC2.1 / DC2.5 charge port · power switch (right-hand side) |
| Cell Format | 18650 or 21700 |
| BMS | In-house 13S BMS, current rating matched to parallel count |
| Connector | Specified per programme (XT60 / Anderson / Higo / Julet / custom) |
| MOQ | From 100 pcs |
| Sample Lead Time | 5–10 working days |
| Mass Production | 2–4 weeks after approval |
Inside Every Pack
The same engineering standards apply to every configuration we ship — from cell selection to the final welded enclosure.
Tier-1 Brand Cells
Samsung, LG, Panasonic, EVE and BAK cells — graded and capacity-matched before assembly.
Multi-Protection BMS
Over-charge, over-discharge, short-circuit and temperature protection on every pack.
Welded Construction
Nickel strips welded for low-resistance, vibration-resistant joints inside a sealed enclosure.
Applications
Certifications Included
Test reports and certificates are included in shipment documentation at no additional cost.
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From 100 pcs · Samples in 5–10 working days · Mass production 2–4 weeks after approval
Frequently Asked Questions
Is the KT-E09-PRO electrically different from the KT-E09?
No. Identical case, identical cell blocks, identical 13S7P 17.5Ah and 13S5P 25Ah builds. The difference is the mounting rail: four fixings at 60mm pitch instead of three at 57mm.
Why would we choose the four-point rail?
Load and vibration. A fourth fixing spreads the pack's mass over more of the down tube, which matters on cargo frames, delivery bikes and any programme where packs are removed and refitted daily. On a light commuter the three-point rail is sufficient.
Can we run both rails across one product line?
Yes, and some brands do — the PRO rail on the cargo model, the standard rail on the city model, with one pack SKU per rail but a shared cell block and BMS. It keeps the electrical qualification and the certification file common across both bikes.
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