Tech OVN

August 2026 · EV Charging · OEM/ODM

15 Questions to Ask an EV Charger OEM Before You Sign

Choosing an EV charger manufacturer for a white-label or OEM programme is a decision you live with for years — through field deployments, firmware updates, certification renewals, and warranty claims. The conversation before you sign the agreement is your best opportunity to find out whether this manufacturer will be a reliable partner or a source of ongoing problems. These 15 questions, grouped by topic, give you a structured way to evaluate any vendor — and a sense of what a good answer looks like.

Commercial questions

These questions establish whether the commercial terms match your deployment model before you invest time in technical diligence.

Q1. What is the minimum order quantity per SKU?

MOQ tells you whether the manufacturer has a standardised platform or builds to order. An MOQ of around 200 units per variant is typical for a mature AC charger platform — the manufacturer has already made the tooling investment and can run smaller batches economically. Very low MOQs on certified hardware may indicate a distributor, not a factory.

Good answer: A specific per-SKU MOQ with a clear break-point for pricing tiers.

Q2. What is the standard lead time from purchase order to delivery?

Lead time determines your inventory planning. A manufacturer with their own production line and component stock can commit to a fixed lead time — four to six weeks from PO is achievable for standard variants. Manufacturers that subcontract assembly or import key components may quote eight to sixteen weeks, and may slip further in constrained markets.

Good answer: A specific lead time commitment, with clarity on what triggers delays and how they communicate them.

Q3. What are the pricing tiers and what drives them?

Volume pricing is standard, but the structure varies. Some manufacturers offer step discounts at 200, 500, and 1,000 units. Others price by annual committed volume rather than per-order quantity. Understand whether tooling, certification, and NRE (non-recurring engineering) costs are included in the unit price or billed separately — these can add significantly to a first-order cost.

Good answer: A clear tiered price schedule, with all fees itemised separately from unit costs.

Technical questions

Technical due diligence covers protocol compliance, firmware ownership, and integration architecture — the factors that determine how much control you have over the product after it ships.

Q4. Which OCPP versions does the charger support, and is it backend-agnostic?

OCPP 1.6J is the current installed-base standard; OCPP 2.0.1 adds smart-charging and security profiles required by many enterprise and fleet operators. A charger that implements both gives you the broadest compatibility. Backend-agnostic means the charger connects to any CSMS over standard OCPP — the manufacturer does not require you to use their backend, and there is no lock-in to their cloud. This is especially important if you are building your own white-label platform.

Good answer: OCPP 1.6J and 2.0.1 supported, with evidence of interoperability testing against third-party CSMS platforms.

Q5. Who owns the firmware, and what do I control?

In a white-label arrangement, the OEM typically owns the firmware codebase. What matters to you is the licence scope: can you push OTA updates independently, configure tariffs and load limits from your CSMS, and receive transaction data directly on your backend — or does every configuration change go through the OEM's support team? The right arrangement gives you operational control even though you do not own the code.

Good answer: Buyer controls configuration, OTA scheduling, and data routing; OEM owns the codebase but does not sit in the data path.

Q6. How are over-the-air (OTA) firmware updates delivered?

Field-deployed chargers need firmware updates for security patches, OCPP compliance fixes, and feature additions. Ask how updates are triggered (CSMS-initiated via OCPP UpdateFirmware, or OEM-initiated centrally), whether updates can be staged by site or by firmware version, and what happens if an update fails mid-way. A manufacturer that cannot clearly explain their OTA update process is one whose chargers will be difficult to maintain at scale.

Good answer: OCPP UpdateFirmware support, staged rollout capability, and documented rollback procedure.

Q7. Is a controller-only option available?

Some CPOs and integrators want the electronics — the OCPP controller, the charging circuitry, the meter — in a board-level form that they can integrate into their own enclosure or infrastructure product. Ask whether the manufacturer offers a controller-only OEM option. If this is your requirement, raise it early — not all manufacturers separate the hardware this way.

Good answer: A defined controller-board product line with its own specifications and certifications.

Q8. What accuracy class is the built-in energy meter?

Built-in metering accuracy matters for revenue-grade billing applications. For tenant billing, fleet charging cost allocation, or CPO settlement, you need a meter that is accurate enough to be defensible. Ask for the accuracy class and the metering standard it conforms to. An in-house meter calibrated and characterised by the manufacturer — rather than a generic module — gives you a consistent, documented accuracy across the fleet.

Good answer: A stated accuracy class per a recognised standard, with calibration records available on request.

IP, compliance, and certification questions

These questions protect your brand and your customers from certification gaps that emerge after deployment.

Q9. What NDA and confidentiality protections are standard?

A white-label manufacturer handles your product specifications, your customer data architecture, and potentially your pricing. A mutual NDA covering design specifications, commercial terms, and customer information should be standard — not something you have to negotiate separately. If a manufacturer hesitates to sign a standard NDA, treat it as a signal about how they will handle your IP during and after the relationship.

Good answer: Mutual NDA offered proactively, with clear scope covering specs, commercial terms, and customer data.

Q10. What certifications does the product currently hold?

Ask to see current certificates — not marketing claims. Relevant certifications for Indian market AC chargers include BIS (for the product category), CE marking (if exported to Europe), and safety certifications covering the charging connector, the power supply, and the enclosure. Ask for certificate numbers and expiry dates, and verify them directly with the issuing body if the volumes are significant.

Good answer: Specific certificate numbers, issuing bodies, scope, and expiry dates — available for inspection before signing.

Q11. Does rebranding require recertification?

This is one of the most important questions and one of the most frequently misunderstood. A brand-only change — new label, new nameplate, same enclosure and electronics — typically does not require recertification under most conformity schemes. Changing the enclosure shape, the cable type, the PCB, or any safety-relevant component generally requires at least a partial re-test and a certificate amendment or reissue. Ask the OEM to show you their change-control procedure and which variants have already been certified.

Good answer: Clear written distinction between brand-only changes (no recertification) and hardware changes (recertification required), with documented examples.

Q12. Who owns the warranty and who pays for warranty claims?

In a white-label arrangement, your customer sees your brand — not the OEM's. Your customer will call you for warranty support. The question is whether the OEM backs you with a manufacturer's warranty that covers parts and repair costs, or whether warranty risk sits entirely with you. Understand the warranty period, what it covers (DOA, systematic faults, individual failures), and the process for claiming — especially for units deployed across multiple sites or states.

Good answer: A written manufacturer's warranty with clear coverage scope, claim process, and turnaround commitments.

Support and supply-chain questions

A charger that cannot be repaired in the field is a charger that gets replaced — at your cost. These questions test whether the manufacturer has thought past the first shipment.

Q13. What spare parts are available, and how quickly?

The components most likely to need replacement in the field are: the power supply module, the RCCB or protection relay, the connector and cable assembly, and the display or HMI module. Ask whether these are stocked in India, what the lead time is from order to dispatch, and whether they are sold individually or only as assemblies. A manufacturer that can ship a replacement PCB within a week is very different from one that ships from an overseas warehouse on a 45-day cycle.

Good answer: Named spare part list with India-based stock and specific lead times.

Q14. What technical escalation path exists for field faults?

Standard email support is not sufficient for a live deployed fleet. Ask whether there is a technical support tier for systematic or difficult faults, what the response time commitment is, and whether you get direct access to an engineer (not just a tier-1 helpdesk). A manufacturer that has not thought about post-sales technical escalation has not thought about what happens when 500 chargers are deployed and one of them develops an unusual fault pattern.

Good answer: Defined escalation path with named contacts and committed response times for P1/P2 faults.

Q15. What is the product roadmap and how are breaking changes communicated?

Hardware and firmware evolve. What you need to know is: how much notice you get before a hardware revision that affects certification or physical compatibility, how breaking firmware changes are communicated before they reach your fleet, and whether you have a say in the OTA update schedule for your chargers. A manufacturer with a published roadmap and a formal change-communication process is one that treats you as a partner rather than a channel.

Good answer: Minimum notice periods for hardware revisions, a change log for firmware versions, and opt-in OTA scheduling for your fleet.

How to use this checklist

Send these questions to every OEM you are evaluating — before a factory visit, not after. The quality of the written answers tells you as much as the answers themselves. A manufacturer that responds with specific commitments, documents, and certificate numbers is organised. One that responds with broad reassurances and redirects you to a sales call for details is not.

Weight the questions by your use case. If you are building a revenue-grade public charging network, metering accuracy and certification scope matter more than MOQ. If you are deploying a private fleet programme with your own CSMS, firmware ownership and OCPP compliance matter more than spare parts lead time.

Use the contact form to put any of these questions to the Tech OVN team — we will give you specific, documented answers for every point on this list.

Frequently Asked Questions

Common questions about choosing an EV charger OEM manufacturer.

MOQ varies widely — from a few hundred units for established manufacturers with standardised platforms to several thousand for heavily customised designs. An MOQ of around 200 units per SKU is common for mature AC charger platforms where the manufacturer carries the tooling investment. Be cautious of very low MOQs (under 50) on hardware that claims full certification — they may indicate an uncertified product or a distributor masquerading as a manufacturer.
It matters more when you have your own backend. OCPP is the standard that lets your chargers talk to any CSMS — including yours — without proprietary integration work. A charger that implements OCPP 1.6J or 2.0.1 fully and passes interoperability testing will connect to your backend in hours, not months. A charger with a proprietary protocol or a partial OCPP implementation will require the OEM's ongoing involvement to maintain the integration, reducing your control over your own product.
In a true white-label arrangement, the OEM owns the firmware and you license it. What matters is what the licence terms allow: can you ship OTA updates without the OEM's approval? Are configuration parameters (tariffs, load limits, branding screens) controllable from your CSMS? Is the data yours — do transactions and telemetry go directly to your backend, or through the OEM's cloud? A good arrangement gives you control over configuration, data, and OTA delivery, even though the OEM owns the underlying codebase.
It depends on what changes. A brand-only change — new label, new colour, same enclosure and electronics — typically does not require recertification under most conformity assessment schemes. Changing the enclosure, the PCB, the cable length, or any safety-critical component generally requires at least a partial re-test and certificate update. Ask the OEM to show you the exact scope of the existing certifications and the change-control procedure for variants. A trustworthy OEM will have this documented.
Ask specifically: what is the lead time for replacement PCBs, contactors, and power modules? Does the OEM stock spare parts in India or only ship from overseas? What is the warranty — who owns it, the OEM or the reseller — and what does it cover (parts, labour, shipping)? Is there a technical escalation path for field faults beyond standard email support? A manufacturer that cannot answer these questions in the sales conversation will not answer them after you have deployed 500 chargers in the field.
Some OEMs offer a controller-only or OEM-board option for CPOs and integrators who want to design their own enclosure or integrate the charging electronics into an existing infrastructure product. This is not universal — it depends on whether the manufacturer has separated its firmware, metering, and communication hardware from its mechanical design. If this is your requirement, ask early in the conversation, as it affects which product line is appropriate and what certifications apply.

Related Reading

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Contact Us

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Talk to Tech OVN about your EV charger OEM requirements

MOQ 200, 4-week lead time from PO, OCPP 1.6J and 2.0.1, in-house metering, and your brand on the product. Get specific answers to every question on this list.

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