A mobile wash and detailing operator sells one thing: a vehicle arriving at the customer's kerb with clean water and leaving with dirty water. That single sentence changes almost every spec decision on the platform. A delivery trike is sized around how much cargo it can drop off. A wash trike is sized around how much liquid it can carry in, how much it must carry back out, and how long the pump can run before the battery is the limiting factor rather than the water tank.
This guide is written for operators and fleet buyers specifying an electric cargo tricycle for mobile car washing, valeting, detailing, fleet wash contracts or pressure-washing work. Every number below comes from our own published cargo platform specifications and production documentation, and the arithmetic is worked through so you can substitute your own route figures.
Why a Wash Route Is Not a Delivery Route
Most of the advice online about cargo trike fleets assumes a delivery duty cycle: leave the depot with a full load, shed weight at every stop, return empty. A wash route inverts that. The vehicle leaves heavy with clean water, stays heavy through the working day, and then returns heavy again with the waste water it has collected. Peak mass is not at the start of the route but somewhere in the middle, when the fresh tank is still half full and the waste tank already holds the first few jobs.
That difference shows up in five places, and each one is a specification decision rather than an operating preference. If you already run field service vehicles, you will recognise the consumable-versus-parts distinction, but the mass profile is the opposite way round.
| Duty dimension | Delivery route | Mobile wash route |
|---|---|---|
| Mass profile | Starts heavy, ends light | Heavy at both ends; peak mass occurs mid-route |
| Stop duration | 2–5 minutes | 30–90 minutes per vehicle washed |
| Consumable | Packages | Water in, waste water out |
| Auxiliary power | None, or a scanner | Continuous 12V pump for hours |
| End of shift | Park and charge | Tank drain, pump flush, equipment washdown |
The third and fourth rows are where most first-time specifications go wrong, and both are covered below.
The Payload Envelope: What the Platform Actually Carries
Our cargo e-tricycle platform is rated at 300 kg for EU-compliant configurations and 500 kg for non-EU markets, with a cargo box volume of 150–500 litres and a chassis weight of 150–220 kg without the box. Those are engineering limits on the frame rails and axle group, not marketing figures, and they are what you have to fit a water system inside.
Water is unforgiving because its density is fixed: one litre is one kilogram. A 100-litre fresh tank is 100 kg of payload before you have added a single pump, hose reel or brush. Work the arithmetic for a modestly equipped unit:
- Fresh water tank, 100 L — 100 kg
- Waste water tank, 60 L, running half full on average — 30 kg
- 12V pressure pump, controller and wiring — 8–12 kg
- Two hose reels with 20 m of hose each — 15–20 kg
- Brushes, mitts, buckets and chemical bottles — 20–25 kg
- Operator weight (where a bench seat is part of the layout) — 75–95 kg
That lands the vehicle at roughly 250–280 kg of working mass, which sits inside the 300 kg EU rating with a margin of only 20–50 kg. The practical reading: on the EU-rated configuration a 100-litre fresh tank is close to the sensible ceiling, and the non-EU 500 kg rating is what buys you a 150–200 litre tank and a second operator. Specify the tank size against the payload figure, not against the box volume, and be explicit about which rating you are ordering. The same payload-first method is what we set out for construction site fleets and for licensed spray application vehicles.
Tank Placement, Baffles and Why a Full Tank Is Not the Worst Case
The frame carries weight well; it handles weight in motion less well. A partially filled tank is more demanding than a full one, because liquid that can slosh moves the centre of mass laterally on every corner. On a three-wheeled platform with a single front wheel, that lateral shift is felt directly at the steering head.
Two practical measures follow. First, specify baffled tanks with internal partitions so the free surface is broken up, or operate in a fill discipline where the fresh tank is topped up between jobs rather than allowed to run down to a third. Second, keep the mass low and centred: mounting the fresh tank over the rear axle group, rather than high in the box or cantilevered over the front, keeps the centre of gravity where the delta layout is most stable. Our cargo platform uses a steel tube chassis with reinforced load-rated tyres at 3.00-12 front and 3.75-12 rear dual, with leaf-spring rear suspension — a configuration chosen precisely because the rear axle group is where commercial payload is meant to sit. Tyre load rating and wear behaviour on loaded platforms are covered in more depth in our cargo tricycle tires guide.
The 12-Volt Question: Running a Pump Without Cooking the Traction Pack
A pressure pump drawing continuously for a working day is the single most common specification error on a wash trike. Operators assume the pump can simply run from the traction battery. That works electrically, but it has to be designed rather than assumed, and it has to be designed before the order is placed.
There are three workable architectures, and the right one depends on your route length and how much water you actually use per job.
- A dedicated 12V auxiliary battery charged from the traction pack through a DC-DC converter. This isolates the pump load from the traction system entirely. It is the safest option for long jobs and the easiest to service, at the cost of an extra battery and converter to maintain.
- Direct DC-DC tap from the traction pack with a properly rated converter. Fewer components and lower cost, but continuous pump draw becomes part of your range arithmetic, and the converter must be sized for pump inrush current rather than running current.
- A separate isolated circuit for the pump and any lighting or heater loads, with its own fuse protection. This is what we recommend where the vehicle also runs a wash-down or water-heating load.
Decide this before the bill of materials is frozen. Retrofitting an auxiliary circuit after the frame has been coated and the box assembled means drilling a finished, powder-coated frame, which creates the corrosion initiation point you spent the coating specification avoiding in the first place. If your supplier treats the electrical layout as a post-sale accessory, that is a signal about how the rest of the order will go. The same discipline applies to the traction electronics, which we break down in the motor controller selection guide.
Corrosion, Chemical Attack and Why the Coating Spec Is the Life of the Vehicle
A wash vehicle lives in the worst environment a vehicle can be asked to work in. It is regularly soaked in water, frequently exposed to traffic film remover, wheel cleaners and degreasers, and left wet overnight. Corrosion resistance is therefore not a cosmetic preference; it is the primary determinant of how many years you get before the frame is a liability.
Our cargo platform specification covers this in three layers. The frame is a steel tube chassis finished with heavy-duty e-coat followed by powder coat, which gives an electrochemically deposited primer coat inside and out before the cosmetic layer goes on. The cargo box is available in welded aluminium sheet for corrosion resistance and weight saving, galvanised steel for impact-heavy duty, or insulated sandwich panel where a cold-chain compartment is needed. Electrical components are specified with motor protection at IP65 and controllers in the IP54–65 band depending on the part.
Two operating rules matter as much as the specification. Use stainless fasteners and drains in the tank and box floor so water does not sit in low points. And never pressure-wash the controller and battery compartment, however tempting it is at the end of a shift — the sealed enclosure that keeps water out at the designed pressure is not rated for a high-pressure lance at close range. The routine side of keeping a wet-service vehicle serviceable is covered in our electric tricycle maintenance guide.
Route-Time Arithmetic: Where a Trike Wins and Where It Does Not
The economics of a wash trike are decided by route density, not by fuel cost. The vehicle wins where jobs are close together and the operator's working time per vehicle is long enough that travel time is a minority of the day.
Take a realistic mid-density route: six vehicles washed per day, 30–45 minutes per vehicle, 10–20 minutes of travel between stops. That is 3–4.5 hours of wash time and 1–2 hours of travel — a total duty cycle comfortably inside a single shift, with the vehicle parked and charging overnight between shifts.
The binding constraint is charging rather than range. The platform runs 60V 32Ah or 72V 40Ah lithium packs with 6–10 hours of charge time on the standard 5A charger. A single-shift wash operation fits that pattern exactly: one vehicle, one overnight charge, one shift. A two-shift operation does not. If you want the same vehicle working a morning and an evening round, you need either a second vehicle, a higher-current charger, or a swappable pack configuration agreed at order time. There is no version of a lunch break that puts meaningful charge back into a 32Ah pack on a 5A charger. We set out the full depot and dock sizing picture in the fleet charging guide and the multi-vehicle site layout in the charging dock station guide.
Where a trike plainly does not win: routes with long highway transits between jobs, or worksites where the customer expects the vehicle to supply its own large volumes of water on demand. Above roughly 150–200 litres of fresh water required per job, you are describing a van or a trailer, and it is better to say so than to specify a trike that will be overloaded on every call. Where the trailer route is viable, the configurations and towing arithmetic are in our trailer guide.
Specifying the Vehicle: A Checklist
Work through the following in order. Each line is a decision that constrains the ones below it.
- Market and rating. EU (300 kg) or non-EU (500 kg)? This determines your tank ceiling before anything else.
- Fresh and waste tank sizes. Size from the payload figure and your per-job water consumption, and specify baffled tanks.
- Auxiliary electrical architecture. Dedicated 12V battery, DC-DC tap, or isolated circuit — decided before BOM freeze.
- Box type. Aluminium sheet for weight and corrosion resistance, galvanised steel for impact-heavy duty, insulated panel if you also need a cold compartment for products.
- Drainage. Low-point drains in the box floor and tank; stainless fasteners throughout.
- Motor and differential. 800W / 1000W / 1200W brushless hub motor with differential, 60V or 72V. The differential matters more on a wash trike than on a delivery trike because you are regularly manoeuvring at close quarters around parked cars.
- Brakes. Hydraulic disc front with dual drum rear and a parking brake. A laden wash trike being parked on a slope while the operator works elsewhere is a real scenario.
- Lighting. Full LED system, with a beacon where you are working at the kerb of a live carriageway.
Order Terms and Programme Risk
OEM orders on this platform start at 50 units per model, with 15–30 days standard lead time and 30–45 days for a first custom-branded run. Pre-production samples ship before mass production, which is the point at which you should be confirming tank mounting, electrical routing and box layout on a physical vehicle rather than on a drawing.
Three clauses are worth insisting on for a wash fleet. Get the electrical architecture documented and approved in writing, because it is the change most likely to be value-engineered out. Get the spare parts position confirmed for the tyre sizes actually fitted — 3.00-12 front and 3.75-12 rear dual are the platform standards and should be continuously available. And ask for the compliance file with each order, which on this platform covers UN 38.3 alongside cell, BMS and test-report documentation. For multi-unit roll-outs the funding structure is worth agreeing early, as covered in the fleet financing guide.
Frequently Asked Questions
How much water can a wash e-tricycle realistically carry?
On the EU-rated 300 kg configuration, budget a 100-litre fresh tank once pump, reels, chemicals and the operator are accounted for. The non-EU 500 kg configuration supports 150–200 litres plus a second operator. Size the tank from the payload rating, not from the box volume. Tank handling on a tricycle platform, including baffling and fill discipline, is discussed in the water and beverage distribution guide.
Can I run the pressure pump from the traction battery?
Yes, but only through a properly rated DC-DC converter, and it must be designed into the order rather than retrofitted. A dedicated 12V auxiliary battery is the more robust choice for long jobs and isolates the pump load from your traction range entirely.
How many vehicles can one wash trike cover per shift?
At 30–45 minutes per vehicle with 10–20 minutes of travel between stops, six vehicles per day sits comfortably inside one shift. The limit is the 6–10 hour charge window on the standard 5A charger, not the range figure.
Will a wash trike rust?
It will if the coating and drainage are wrong. Specify an e-coat plus powder-coat frame, aluminium or galvanised box, stainless fasteners and low-point drains, and do not pressure-wash the sealed controller and battery compartments.
Build the Route Around the Right Platform
A wash trike works when the platform is specified around a liquid duty cycle from the start: baffled tanks inside the payload rating, an auxiliary electrical circuit that was designed rather than added, coating and drainage chosen for permanent wet service, and a route whose density and shift pattern match the charge window. Get those four right and the vehicle will outlast several van replacement cycles, in the same way a properly specified work-rated platform outlives a repurposed consumer cargo bike. Get the electrical architecture wrong and you will be drilling a coated frame within a month.
Spec a Wash Fleet on a Real Platform
Send us your route density, per-job water volume and shift pattern. Our export engineers will come back with a tank and payload configuration, the auxiliary electrical layout and an FOB quote for a 50-unit roll-out.
