Elsewhere I read that V2G will not become standard until 2025
insideevs.com
Does anyone know if manufacturers will be able to retrofit V2G capability through software upgrades to support the new protocols, or is it likely to require additional hardware to support V2G functionality.

CharIN: CCS Combo Standard To Offer V2G By 2025
CharIN e.V. has released the roadmap for grid integration (V2H, V2G) of charging systems based on the Combined Charging System (CCS).
