3.3 kW Air-cooled On-board Charger(OBC) Assembly

Product Overview

The 3.3 kW Air-cooled On-board Charger Assembly is the dc charger that lives on the vehicle. Single-phase mains goes in at 220 VAC nominal; regulated DC comes out to the traction pack. It is sized for light and specialty electric vehicles rather than long-range passenger cars — golf cars and low-speed vehicles, electric motorcycles, tricycles and canopy vehicles, forklifts, battery-powered mowers and small electric vessels.

What makes it useful to a builder with more than one platform is the range behind a single design. Seven output variants share the same control architecture, the same parameter structure, the same CAN dialogue and the same housing family, covering packs from 24 V up to 540 V. A new vehicle model does not force a new charger qualification: you move to the variant that matches the pack, keep the wiring method and the configuration approach, and carry on.

Behaviour is set in firmware and stored parameters rather than in fixed analogue hardware, so a unit can be prepared for the pack it will actually charge. Compatibility work then moves from "does the charger fit this pack" to "what parameter set does this pack need" — a much shorter conversation at the prototype stage, and a much shorter one when a pack supplier changes cells mid-programme.

In daily use there is nothing for the driver to operate. The vehicle is plugged in, the controller and battery management system run the charging dialogue over CAN, and the charger holds the current and voltage limits it is given until the pack is full. Service teams deal with one familiar unit across a mixed fleet instead of a different box for every voltage class.

Output Variants by Pack Voltage

Control and Protection Platform

• Full digital control. The conversion stage is managed digitally end to end, so current limits, voltage windows and protection thresholds live in a parameter set you can read, change and document. That is also what lets the same board be prepared as a custom dc power supply for a pack window that does not sit exactly on a catalogue variant.
• Active PFC front end. The input stage draws current in step with the mains waveform instead of in short pulses, which is what a depot with several vehicles charging on one supply needs in order to keep the installation stable and the upstream protection calm.
• Protection in two layers. Supervision runs in both software and hardware: firmware watches current, voltage and temperature, while independent hardware limits act even if the firmware does not. A fault trips protection instead of propagating into the pack.
• CAN communication. Charger status, available limits and fault codes travel over CAN to the vehicle controller or battery management system, so the charging dialogue is run by the vehicle rather than by the charger on its own.
• Bootloader and background-upgradable parameters. Firmware and settings can be updated through the service interface without opening the sealed housing — useful when a vehicle is already in the field, or when a limit has to be adjusted after dyno testing.
• EMC position, stated as it is. The design is built to GB electromagnetic compatibility requirements and is adaptable to CE and UL. Where a programme needs formal certificate documents in the file, ask for the current EMC documentation when you specify the unit so the paperwork can be agreed early.

Cooling, Sealing and Mounting

Cooling decides where an on-board charger can be mounted, and this unit is air-cooled on purpose. Heat moves from the power stage into the housing and out to the surrounding air, so there is no coolant circuit, no pump, no hose route and no bleed step at end of line. On a golf car, a mower or a light utility vehicle that is often the difference between a charger that fits the programme and one that does not, and it is why air-cooled designs remain the default request for dc ev charger manufacturers serving those platforms.

The housing is sealed to IP67. In practice that means dust cannot enter and the unit withstands temporary immersion, so it can be mounted low on the chassis or in an area that sees spray, washdown water and road grit instead of being confined to a dry cabin.

Over-temperature protection is built in. If internal temperature climbs beyond the designed range, protection acts before the power stage is damaged. If your duty cycle is heavy, or the mounting position is enclosed, ask our engineers for the derating curve and the exact trip and recovery behaviour so the vehicle's thermal strategy and the charger's protection line up.

Mounting matters as much as the rating. Leave clear air on the finned faces, keep the housing away from exhaust runs, brake heat and other hot components, and bolt it to a rigid part of the structure. Where the chassis vibrates, plan the mounting points and any anti-vibration measures at the same time as the wiring route — an enclosed compartment needs an airflow path, not just a bracket.

Tell us three things and most installation questions answer themselves: the duty cycle, the ambient temperature the vehicle actually sees, and whether the unit will be washed down. Those three also decide whether a protective cover helps or simply traps heat.

Applications by Vehicle Type

• Golf cars and low-speed vehicles. Clubs and resorts charge a whole fleet overnight from a single-phase supply. The pack is small, the space under the body is tight, and the vehicle is washed and left outdoors, so a sealed air-cooled unit fits the routine better than one that needs plumbing.
• Electric motorcycles and scooters. A compact pack and a short charge window, on a vehicle parked wherever the rider stops. The rider plugs into the on-board dc charger and the vehicle controller takes over; the unit itself has no controls to misuse.
• Electric tricycles and canopy vehicles. Delivery and passenger work, often charged twice a day from whatever socket the depot has. Wide input tolerance matters more here than headline power, because the mains is rarely ideal.
• Forklifts and high-lift industrial vehicles. Opportunity charging between shifts in a warehouse that generates dust and rarely offers a clean, dry mounting point — a duty cycle that tests the sealing long before it tests the power stage.
• Battery-powered mowers and power tools. Fleet operators with dozens of machines want one charging platform across a product family, so the same parameter method and the same service routine cover every machine in the yard.
• Small electric vessels. Dockside charging with spray and humidity around the installation. Confirm salt-spray and corrosion requirements for your berth when you specify the housing and the mounting position.

Installation and Commissioning

1. Confirm the pack window before anything is drilled, so a variant question is settled while the unit is still on the bench rather than after it is mounted.
2. Pick the mounting position for airflow and protection: clear air on the finned faces, away from exhaust and brake heat, bolted to a rigid part of the structure.
3. Route the DC output to the pack through the vehicle's own protection — fuse, contactor and isolation as your electrical architecture requires — and keep the DC run short and secured.
4. Connect the CAN bus to the vehicle controller and agree the message set with our engineers before the first power-up. The charger is controlled over CAN, so a mismatched protocol shows up as a fault rather than as a slow charge.
5. Load or confirm the parameter set that matches the pack. This is the step that turns a standard unit into a custom dc power supply for that vehicle: voltage window, current limit and protection thresholds are all set here.
6. Run the first charge and watch it: input current, output current, case temperature and the CAN log. A clean first cycle at rated conditions is the checkpoint where most integration problems are caught.
7. Record the configuration the unit shipped with. On a production programme that record becomes the reference for every following vehicle, and the baseline for any field update.

Ordering and Configuration

Every unit is configured against a vehicle rather than picked off a shelf, so the useful starting point is a short specification: the charge profile your pack actually sees, the connector and cable length you need, the CAN protocol your controller speaks, and where on the vehicle the unit will sit. Send the mounting orientation and the ambient conditions with it — a charger behind a wheel arch and a charger under a seat are specified differently.

As dc ev charger manufacturers, we work from that specification rather than from a fixed part number. If your pack sits between two variants in the list, say so; the window is checked against that profile before the model code is confirmed.

Commercial terms are agreed per order. Your sales contact can confirm the current lead time for the variant you need, the packing method for your shipping route, and the documentation set that travels with the unit — wiring diagram, parameter list and the EMC statement for your project. Incoterms, payment terms and the shipping arrangement are set per order and per destination, so settle them at the same time rather than at dispatch.

If you need a unit for bench testing or a prototype build before committing to production, ask your sales contact about sample availability and how a prototype unit is configured and labelled. For batch orders, packing is normally agreed with your forwarder; units travel with the connections protected and the housing braced, and the exact packing specification for your route is confirmed with the order.

Plan spares at the same time. Most service operations keep one unit of their most common variant on the shelf rather than a full set of voltage classes, which covers the fleet without tying up capital in parts that move slowly.

Charge Time & Pack Sizing

• Time is energy divided by held power. A charge adds kWh to the pack at whatever rate the unit can sustain. While the 3.3 kW dc charger sits at full output it delivers about 3.3 kWh per hour, so the first figure to establish is how many kWh your pack actually takes between the state of charge you normally start from and the point where the battery management system ends the charge.
• The current ceiling governs the low-voltage variants. Power is voltage multiplied by current, and every model code carries its own current limit. The 24 VDC variant is capped at 0–100 A, so it climbs towards the 3.3 kW rating only near the top of its 0–36 VDC window; the 48 VDC variant behaves the same way against its 0–60 A limit. Size a schedule on the current limit of the code you are considering, not on the headline 3.3 kW alone.
• Allow for the taper at the end. The last part of a charge is deliberately slower: the vehicle reduces demand as the pack approaches its final voltage, and the charger follows the limits it is given over CAN. A pack that takes just over three hours of full-power charging can take noticeably longer end to end, so build the taper into the charging window rather than assuming an average rate.
• Overnight charging is the natural fit. A golf car, a mower, a forklift or a light utility vehicle that is plugged in at the end of a shift has hours to spare. At 3.3 kW the pack of a typical light or specialty vehicle refills comfortably before the next shift, which is why this platform is usually specified for depot and clubhouse charging rather than for fast top-ups.
• Opportunity charging needs the arithmetic checked. Where a vehicle only stops for a short break, multiply the length of the stop by the power the unit holds at that pack voltage and compare the result with the energy the next run consumes. If the top-up falls short, the answer is a longer stop, a lower-consumption duty cycle, or a higher-power model from the range — decide it before the charger is mounted, not after.
• Three figures close the question. Send the pack capacity in kWh, the state of charge you normally start from and the length of the window you have available. Our engineers will work out the expected charge time on the model code you are considering and say whether the 3.3 kW platform meets your schedule. The rated output voltage and current range differ by code, so quote the code with the figures.

Technical Support & Model Matching

Buying power-conversion hardware rarely fails on the unit itself; it fails on the match. Tell our engineers the input and output voltages, the current your load draws and how the unit will be controlled and mounted, and they will confirm the right configuration or quote a customized one. Lincoren has run its own full-power R&D platform and pilot base in Nanjing since 2010, so selection, wiring and commissioning questions go to the people who designed the unit, not to a call centre. Fault diagnosis and replacement support continue after delivery.

FAQ