E-car - Bidirectional Charging: Battery Storage 2.0

Hello everyone,

I will buy a new car this week. This time it is supposed to be an electric car.

The decision will be between the VW ID 5 GTX and the Audi Q4 e-tron 50 quattro.

As part of my research, I found out that the ID 5 has a really cool and new additional feature for electric cars: The 77kWh battery can be charged and discharged bidirectionally. This means: the battery of the ID 5 serves as a storage medium for self-generated photovoltaic electricity. That is pretty brilliant!

Has anyone here already dealt with this intensively and can report something about it?

And do we maybe also have a few car nerds among us who know if the Q4 e-tron is equipped with the same technology?

The ID 5 and the Q4 e-tron are both manufactured in Zwickau and are largely identical. Does that also apply to the battery technology?

If this really works reliably, in my opinion, it would be another milestone towards an even higher degree of self-sufficiency!

I look forward to the discussion…

Bidirectional charging is a nice idea, but not yet feasible at the moment. - The regulatory requirements are not yet in place (V2G, V2H) - Wallboxes that can do this are very expensive. - What about battery lifespan due to the increased (dis)charging cycles?

All in all, still a thing of the future.

Bidirectional charging is a nice idea, but currently not feasible. ... - How is the battery life affected by the increased (dis)charging cycles?

this is exactly the problem:

depending on (dis)charging technology, temperature, and electrode design, Li-ion batteries last about
>500 full cycles (defined as about 70% remaining capacity). With partial cycles correspondingly longer. If one were to fully utilize this and operate a daily storage system (charging with solar during the day, consuming at night), then the battery would already be old after about 1.5 years without even having driven 1 km. Replacement generally costs > €10,000.

Everyone has to decide what is important to them

Unfortunately, VW is still very reserved about the details - the function is also supposed to be released for ID.4s via software update, so I am also very interested, as I can well imagine using mine for it as well.

Theoretically, there is a standardization for Vehicle 2 Grid as ISO15118-20 (draft), which, for example, would be retrofittable for the openWB Pro via software update according to the manufacturer. The charging station itself does cost a bit more, but is still comparatively affordable.

However, everything suggests that the function in the VW implementation requires a DC charging station - which in turn can become really expensive, currently starting at just under 10,000 euros, and that without V2G support.

I hope VW thought about this and that they will offer a more cost-effective solution than ID.Charger.

Bidirectional charging is kind of a thing

- Battery wear
- DC technology required in the household (price?)
- regulatory-wise, to my knowledge, not allowed in Germany
- VW announced it for 2022, whether and when anything will actually come ... so far they have not exactly distinguished themselves with their software

Means: the battery of the ID 5 serves as a storage medium for self-generated photovoltaic power. That is pretty brilliant!

Preferring to charge with your photovoltaic power is not a big deal and possible with the right equipment (WB, house electrics). But you can't really get anything out of it, at least not into the building's grid. For example, the Ioniq 5 can charge smaller consumers and other e-cars relatively slowly via an adapter. For the e-scooter in the trunk, the e-bike on vacation, or roadside assistance, though, definitely quite handy.

We recently had this topic here. It is a nice idea when you read about it or when someone raves about it. But in practice, unfortunately, it is a pipe dream.