Drivetrain
| Motor Controller | Curtis 1228-3435 — 36V, 70A, regenerative braking |
|---|---|
| Motor | Brushed DC, ~1000W, 36V |
| Power Delivery | Chain drive via reduction gearbox |
DIY Electric Go-Kart Build
E-Kart
Shopping cart frame. Scooter drivetrain. Built from what was already there.
Technical Specifications
Every subsystem on the kart, from the salvaged scooter drivetrain to the dashboard electronics, documented as it's actually built.
Battery System
| Configuration | Dual 36V Li-ion packs, manually switched (not run in parallel) |
|---|---|
| Switching | Manual selector switch between packs |
| Switch Protection | Capacitors + Schottky diodes prevent power interruption while switching |
Power Electronics
| Lighting Supply | DC-DC buck converter, 36V → 12V |
|---|---|
| Logic Supply | DC-DC buck converter, 36V → 5V for the microcontroller |
| Monitoring | Per-battery current and voltage monitoring |
| Protection | 20A circuit breaker |
Dashboard
| Speedometer | GPS-based, analog-style gauge, 0–80 km/h |
|---|---|
| Status Display | Small OLED display |
| Start Control | Illuminated push-start button |
| Ignition | Discreet key switch |
| Horn | Standard 12V horn |
Lighting
| Underglow | Underbody LED strip |
|---|---|
| Front | Headlights |
| Rear | Rear lights |
| Signals | Turn signals |
| Control | All lighting switched through a relay module driven by the microcontroller |
Cooling & Safety
| Battery Monitoring | Waterproof temperature sensor, continuous monitoring |
|---|---|
| Motor Monitoring | Waterproof temperature sensor, continuous monitoring |
| Controller Monitoring | Waterproof temperature sensor, continuous monitoring |
Chassis
| Frame | Repurposed shopping-cart frame |
|---|---|
| Stance | Lowered |
| Tires | Four off-road tires |
Performance Targets
| Top Speed | ~30 km/h |
|---|---|
| Incline Capability | ~10% |
| Rated Combined Weight | ~100 kg |
Build Photos
Photos go up here as the build progresses. Until a real photo is taken, a slot shows what belongs there.
Build Log
A running, dated record of build milestones — newest entries first.
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Lighting and underglow test
underglow-test.jpgUnderbody LED strip lit up during the first lighting testRan the full lighting circuit for the first time: underbody LED strip, headlights, rear lights, and turn signals, all switched through a relay module controlled by the microcontroller instead of being wired directly to switches.
First power-up went cleanly — no shorts, no relay chatter, and current draw on the 12V rail stayed within what the buck converter is rated for with everything on at once.
Still to do: mount the off-road tires, fit the horn's final bracket, and start road-testing for the ~30 km/h / ~10% incline / ~100 kg performance targets.
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Dashboard electronics installed
dashboard-electronics.jpgDashboard electronics: OLED status display, push-start button, and key switchThe dashboard cluster is in: a GPS-based speedometer with an analog-style 0–80 km/h gauge face, a small OLED display for status readouts, an illuminated push-start button, a discreet key switch, and the horn.
The 36V-to-5V buck converter now powers the microcontroller driving the OLED and gauge logic, and the 36V-to-12V converter is feeding the button illumination and horn for now, ahead of the lighting circuit going in.
Waterproof temperature sensors for the battery, motor, and controller are wired back to the same microcontroller so their readings can show up on the OLED status display.
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Dual-battery switch wired with protection diodes
battery-switch-panel.jpgManual dual-battery switch panel with capacitor and Schottky diode protectionWired in the manual switch that selects between the two 36V Li-ion battery packs. The packs are never run in parallel — the switch always routes power from exactly one pack at a time.
To avoid a power interruption at the controller during the moment of switching, we added capacitors across the supply rails plus Schottky diodes on each pack's output. Bench testing confirmed the controller stays powered through a switch-over instead of browning out.
Also added inline current and voltage monitoring taps for each pack ahead of the switch, feeding into the dashboard electronics planned for the next update.
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Controller and motor mounted
controller-wiring.jpgCurtis controller wiring during the rebuildchain-drive-gearbox.jpgChain drive and reduction gearbox connecting the motor to the rear axleThe Curtis 1228-3435 motor controller and the brushed DC motor — both salvaged from the donor mobility scooter — are now mounted to the frame.
The motor drives the rear axle through its original chain and reduction gearbox, relocated and re-aligned to suit the shopping-cart frame's geometry. Controller wiring is routed and secured but not yet connected to the battery system.
Bench-tested the motor directly off a lab supply to confirm it still spins freely and draws a sane no-load current before committing to final wiring.
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Frame stripped and prepped
frame-strip-prep.jpgShopping cart frame stripped down and prepped for conversionThe shopping-cart frame that forms the basis of the build has been fully stripped down: wheels, basket, and folding mechanism removed, and the bare frame cleaned up and treated for rust.
With the frame on the bench, we mapped out where the lowered stance will sit relative to the axle mounts, and confirmed there's enough clearance for the drivetrain components salvaged from the mobility scooter.
Next up: mounting the motor and controller.