What Is a Bidirectional OBC? V2L, V2V, and V2G Explained
What is a bidirectional OBC? Learn V2L, V2V, and V2G, how bidirectional charging works, when commercial EVs need it, and what to specify. Read the full guide.
Related reading: Air Cooling vs Liquid Cooling for OBC · CAN Communication and BMS Integration Checklist for OBC · OBC RFQ Checklist: What EV Manufacturers Should Provide Before Requesting a Quotation
FAQ
Is a bidirectional OBC the same as a V2G charger?
No. A bidirectional OBC is the hardware that can discharge. V2G is a specific use of that hardware to feed the grid, with grid approval and metering. A bidirectional OBC can support V2L and V2V without supporting V2G.
Can I use V2L while the vehicle is charging?
Usually not at the same time in the same mode. Confirm with the supplier whether the unit can charge and discharge simultaneously, or whether it switches modes. Do not assume simultaneous operation.
Does V2L drain the battery too much to drive home?
It can, if there is no SoC limit. That is why a minimum SoC cut-off is essential. Set the cut-off with the BMS team, based on the distance to the next charger and the reserve the fleet needs.
Do I need liquid cooling for bidirectional?
For the Echelon bidirectional unit, yes — it is listed as liquid cooled. For other bidirectional units, check the specific model. Bidirectional operation at full power generates heat in both directions, so cooling is more demanding than for charging alone.
What should I ask the supplier for?
Ask for the discharge power and AC output specification, the V2L / V2V test data, the CAN messages for discharge control, the liquid cooling requirements, and the list of standards and approvals for the specific model. Confirm V2G separately — it is not included by default.
Related Echelon Products
See the full range on the products page.
Next Step
Define your use case in one sentence — for example, 'power 3 kW of tools for 2 hours from a 96 V utility vehicle, preserving 20% SoC for driving' — and send it to the Echelon engineering team with a request for the bidirectional datasheet, discharge specification, and RFQ. That sentence is the starting point for a correct specification.
To start, share your vehicle and battery requirements through our contact page, and see how a custom programme is scoped on our OEM/ODM page. Before requesting a quotation, the OBC RFQ checklist lists the inputs that let Echelon quote accurately in one pass.
About Echelon Charger
Echelon Energy Technology specializes in onboard chargers, DC/DC converters, and integrated EV power solutions for commercial and specialty electric vehicles.
For technical discussions, product selection, or OEM/ODM cooperation:
Email: nancy@tici-energy.com
WhatsApp: +86 18114665311
