Quick answer: for most people, no. Hub-motor and controller kits are widely sold, but building your own scooter means sourcing and matching a lithium-ion battery and charger yourself, which is exactly what UK fire services warn is a major fire risk. A home-built scooter is still an e-scooter (and in the UK, a motor vehicle) in law, so it gains no extra rights to use public roads, and it may be hard to insure.
Building your own electric scooter, or motorising an ordinary kick scooter, can look like a cheap and satisfying project. The parts are easy to find online. But the most dangerous part of any e-scooter, the battery, is also the part a DIY builder has least control over. This guide explains what is in a typical kit, what the fire services say, and what the law says about home-built scooters.
What kits are available?
Hub-motor wheel kits
The most common kit replaces a wheel with a motorised one. A typical example is a 10-inch hub-motor kit from the manufacturer KUNRAY, which lists these components:
- A 350W brushless hub motor built into a 10-inch wheel with a pneumatic tyre and inner tube (10 x 2.0).
- A drum brake built into the motor wheel.
- A brushless controller (15A).
- A display.
- Brake levers with a power cut-off.
- A thumb throttle.
The kit is offered in 24V, 36V or 48V versions. Importantly, the product page does not list a battery or charger among the contents, and does not mention any safety certification. That is typical of many kits: you have to buy the battery and charger separately.
Controllers and electronics
Controllers, throttles and displays are also sold separately. US parts retailer ElectricScooterParts.com explains that controllers are rated by voltage and wattage and must match the motor: controllers for brushed motors have two power wires, while brushless ones have three phase wires plus sensor wires. It lists examples such as a 36V 500W controller rated at 25 amps and a 36V 1000W unit at 32 amps, with under-voltage protection that cuts power at around 31 to 31.5 volts to stop the battery over-discharging. Getting these matches wrong can damage components or create overheating risks.
Battery packs
This is where the risk lies. A DIY build needs a battery of the right voltage and capacity, with a battery management system (BMS) that protects the cells, and a charger designed for that exact battery. Buying these as separate items from different sellers is precisely the scenario fire services warn against.
What the fire services say
London Fire Brigade’s guidance on conversion kits was written for e-bikes, but the points apply equally to scooters because the batteries and chargers are the same kind of technology. It warns that:
- Batteries and chargers bought separately may not be compatible or meet UK safety standards.
- Second-hand batteries are particularly risky because they may already be damaged or degraded.
- DIY installation can damage the kit, increasing the chance of battery failure.
Its advice is to buy from established retailers, avoid second-hand batteries, never tamper with battery components, use the charger the manufacturer specifies, and have a professional carry out the installation. Its general e-scooter guidance adds that there is, on average, a fire from a lithium-ion battery in an e-bike or e-scooter every two days in London, and that failing batteries can ignite quickly and produce intense, fast-spreading fires with toxic smoke.
The National Fire Chiefs Council says anyone buying a conversion kit should buy from a reputable seller, check it complies with British or European standards, take care on online marketplaces, and check that components are compatible if buying them separately. The UK government’s safety message says to only use the manufacturer’s recommended battery or charger and never to modify or tamper with the battery.
The certification gap
A factory-built scooter can be tested as a complete system. In the US, the Consumer Product Safety Commission has urged manufacturers to certify e-scooters to UL 2272, which evaluates the electrical drive train, battery and charger together, with certification from an accredited lab. A kit assembled at home from parts made by different companies has never been tested as a system. The City of Berkeley advises using original manufacturers’ chargers and batteries with labels from a nationally recognised testing laboratory, and avoiding aftermarket or third-party batteries.
The law: a DIY scooter is still an e-scooter
Building a scooter yourself does not change how the law treats it:
- UK: the government classes e-scooters as motor vehicles and says it is against the law to use a privately owned one on public land. To use one legally on a road, it would have to meet requirements including insurance, licensing, registration and technical standards, which in practice e-scooters cannot. A home-built scooter is still limited to private land with the landowner’s permission.
- Ireland: a legal e-scooter must meet the 20km/h design speed, 400W and 25kg limits, have front and rear lights and two independent brakes, and must not have a seat. A home build has to meet all of these to be ridden on public roads.
- Australia: in Victoria, a device outside the legal e-scooter definition (25km/h, 45kg) is treated as an unregistered motor vehicle. Queensland requires e-scooters to be limited to 25km/h and sets size and equipment rules.
- Canada: Ontario’s pilot sets limits of 500W, 24km/h and 45kg, with lights, a bell or horn and brakes.
- US: rules vary by state and city, and Consumer Reports notes there is no federal safety standard for adult consumer e-scooters.
A kit that raises power or speed can also take an otherwise compliant scooter outside these limits. The European PLEV standard EN 17128, for example, only covers vehicles designed for up to 25km/h with batteries up to 100V DC.
Insurance
Because UK law treats a private e-scooter as a motor vehicle, the government lists insurance among the requirements for road use, and home-built scooters face the same problem as factory-made ones. Separately, if you keep and charge a home-built lithium-ion battery at home, ask your home insurer whether that affects your cover before you start. Do this in writing so you have a record.
What about building a scooter from scratch?
A full ground-up build combines all of the above: a frame, a hub-motor wheel kit, controller, throttle, display, brakes, and a battery pack and charger. The mechanical parts are the easy bit. The battery pack, whether bought ready-made or assembled from cells, is the part where fire services’ warnings about incompatible, uncertified and second-hand batteries apply most strongly, and assembling your own lithium-ion pack is well beyond a typical DIY skill set. If you do go ahead, the minimum is a complete, matched battery and charger from an established retailer, installed or checked by a qualified professional, as London Fire Brigade recommends.
Are they worth it?
| Consideration | Factory-built scooter | Kit or DIY build |
|---|---|---|
| Battery and charger matched and tested as a system | Yes, from reputable makers | Depends entirely on your sourcing |
| Safety certification such as UL 2272 | Available on many models | Rarely, if ever |
| Legal status on public roads | Same rules apply | Same rules apply |
| Warranty and recalls | Usually | Limited to individual parts |
| Learning experience | Low | High |
If you enjoy tinkering, the mechanical side of scooters, such as brakes, tyres and bearings, offers plenty to learn without the battery risk. If you want a working e-scooter, a factory-built one from a reputable seller, with its own certified battery and charger, is the safer choice.
If you already have a converted scooter
- Charge it only while you are awake and at home, never overnight, and unplug when finished.
- Do not charge or store it on an escape route such as a hallway, and fit a working smoke alarm nearby; the National Fire Chiefs Council suggests heat alarms in garages and kitchens.
- Stop using the battery if it is swollen, leaking, dented, discoloured, unusually hot or smells odd.
- Never dispose of a damaged battery in household waste. Use a proper recycling point.
- If a fire starts: get out, stay out and call 999 (or 911 in North America).
Sources
- KUNRAY: 10-inch scooter hub motor kit (product page) (cnkunray.com)
- ElectricScooterParts.com: 36 volt electric scooter speed controllers
- London Fire Brigade: E-bike conversion kits, fire risks and safety advice (london-fire.gov.uk)
- London Fire Brigade: E-bikes and e-scooters fire safety advice (london-fire.gov.uk)
- National Fire Chiefs Council: E-bikes and e-scooters fire safety guidance (nfcc.org.uk)
- GOV.UK: Government safety message on e-bikes and e-scooters
- City of Berkeley: Reduce lithium-ion battery fire risk (berkeleyca.gov)
- US CPSC: Letter to micromobility manufacturers on UL 2272 and UL 2849 (December 2022) (cpsc.gov)
- Genorma: EN 17128:2020 Personal light electric vehicles, requirements and test methods (genorma.com)
- GOV.UK: Guidance on powered transporters
- GOV.UK: E-scooter trials, guidance for users
- RTE News: What are the new e-scooter regulations? (May 2024) (rte.ie)
- Victoria Police: Electric powered scooters (e-scooters) (police.vic.gov.au)
- Queensland Government StreetSmarts: E-scooters, e-skateboards and e-unicycles (streetsmarts.initiatives.qld.gov.au)
- Government of Ontario: Electric kick-style scooters (e-scooters) (ontario.ca)
- Consumer Reports: We tested 13 electric scooters. We don’t recommend any (consumerreports.org)