Who Actually Makes Your On-Board Charger: Reading the Supply Chain Behind the Label

Most on-board charger enquiries reach a buyer through a trading company, an agent or a brand that used to assemble in-house. The label on the unit rarely says which. That matters because the party that owns the production line also owns the process window, the incoming inspection and the answer to a change notification — and those are the things that decide whether year-three units still match the samples you approved.

The four arrangements you will actually meet

Buyers tend to treat “factory” and “supplier” as synonyms. In charging hardware they are not. The four arrangements below cover nearly every quote that lands on a purchasing desk, and each one moves a different part of the risk.

Arrangement	Who owns the design	Who owns the line	What you are really buying
Trading company	The factory behind it	Someone else	Access, logistics and paperwork. Fine for spares, weak for a platform.
ODM	The supplier	The supplier	A proven design with a catalogue of options. Fast, but your differentiation is limited to what they already built.
OEM / build-to-print	You	The supplier	Your specification, their process. Only works if you can write and audit the specification.
In-house	You	You	Control, at the cost of capital and a competence you have to keep warm.

The failure mode is a mismatch, not a bad arrangement. A buyer with no power-electronics team who orders build-to-print gets a unit that meets the drawing and not the vehicle. A buyer with a strong team who orders an ODM platform pays for engineering it then spends two years trying to change.

Three questions that separate a factory from a reseller

1. Who is the manufacturer on the R10 approval?

A UNECE R10 approval names a manufacturer and a manufacturing address. If the document names a company you have never heard of, you have found the factory — and you have also found out who is accountable for conformity of production. Ask for the approval number and check the holder. A supplier who cannot produce the document is either sourcing the unit or has not yet type-approved it, and both answers change your timeline.

2. What happens when a sub-supplier changes a part?

Chargers are assemblies of bought-in magnetics, film capacitors, switching devices and a controller. Any of those can be second-sourced by the factory without the form or fit changing and without the performance staying the same. A written change-notification clause — with a defined notice period and a re-qualification trigger — is worth more than a factory tour. If the answer is “we would tell you”, the clause does not exist.

3. Can I see the test bench, not the showroom?

What you want to look at is the end-of-line test: hipot, functional load, and a record that is retained against the serial number. A line that tests 100% of units and keeps the data can answer a field-failure question in a week. A line that spot-checks cannot answer it at all, and the answer will arrive as a replacement shipment instead of a root cause.

What this means for a first order

For a first platform, the practical sequence is: pick the arrangement that matches your in-house capability, ask for the three documents above before commercial terms, and put the change-notification clause into the quality agreement rather than the purchase order. Buyers who skip the clause usually rediscover it during a field campaign, which is the most expensive possible time to learn who changed a core.

The cooperation models page sets out how we split design responsibility on OEM and ODM programmes, and the R10 and ISO 26262 document set lists what a supplier should be able to hand over before a nomination.

Frequently asked

Is a trading company always a bad choice?

No. For low-volume spares, accessory lines or a market test, a trading company with good logistics can be the cheapest route to a working unit. It becomes a bad choice when the product needs change control, traceability or a type approval in your name.

Can a factory build to my design without owning the certification?

It can build, but the approval has to be held by a manufacturer — normally the party that places the unit on the market under its own name. In practice that means either the factory extends its approval to your variant, or you become the manufacturer and take on conformity of production yourself.

How do I tell whether two brands come from the same line?

Compare the R10 approval number, the enclosure tooling marks and the date-code format. The same factory will usually reuse the tooling and the code format even when the label, the connector and the firmware differ.

What should a factory audit cover for charging hardware?

Incoming inspection of magnetics and capacitors, the SMT line’s reflow profile records, the potting and curing process, the end-of-line hipot and load test with data retention, and the EMC pre-compliance bench. The assembly area is the least informative part of the visit.