Germany's Plug-In Battery Rulings: A Distributor Evidence Ladder

Sep 30

6 min read

A certificate lands in your inbox. The manual says 800 W. The sales deck says “plug and play.” Is the product ready for a German listing?

Not yet.

German media returned to this question in September 2026 after courts in Bochum and Osnabrück maintained restrictions involving certain plug-in storage systems. The headlines were sharp. The underlying lesson is narrower: the cases concerned particular products, connection scenarios and advertising claims. They did not ban balcony batteries as a category.

For a distributor, that distinction is the whole story. A court headline cannot approve or reject the next product in your warehouse. It can, however, expose a weak release process. Many teams have a certificate, a manual and a sales deck, but no controlled chain connecting the exact unit to the exact words used to sell it.

Here is a better approach: a five-level evidence ladder.

First, separate the case from the category

The published text of the Bochum decision, 12 O 29/26, deals with one storage product and a set of representations around ordinary household sockets. The court maintained parts of an interim injunction involving distribution and claims such as “plug & play,” VDE/IEC conformity and overload protection. It also left some technical questions unresolved because the relationship between standards could not be settled without expert evidence.

That is not a minor footnote. It prevents two bad conclusions.

The first is alarmist: “Germany has banned plug-in batteries.” The second is complacent: “Our product has a certificate, so the case is irrelevant.” Neither conclusion follows from the available material.

The useful question is simpler: can you trace every claim on the product page back to the exact product, configuration and evidence file?

Level 1: Freeze the product identity

Start with the item you will actually ship, not the product family in a supplier presentation.

Record the commercial model, internal SKU, hardware revision, current firmware, app version, included inverter or meter, cables, plug, accessories, manual revision and responsible supplier. Where software can change an operating limit, the software version belongs in the identity record too.

“Same series” is not precise enough. A changed connector, bundled meter or firmware limit may create a different configuration from the one in the report. If the file cannot identify the shipped unit at this level, stop. More marketing copy will not repair the gap.

Level 2: Describe the configuration, not the category

“Balcony battery” is a category. “AC-coupled” is a topology. Neither tells you exactly how one system will operate in a German home.

A controlled configuration sheet should show the energy path, maximum selectable operating values, connection method, meter or control dependencies, and combinations permitted by the manual. It should also distinguish a user-selected setting from the maximum the system can be configured to deliver.

That distinction appears in German official guidance for plug-in solar: the highest selectable value matters for determining the relevant power value under the EEG special rules, even if the user chooses a lower setting. This does not decide every storage-safety question. It does show why a screenshot of an 800 W setting is not a complete product description.

So replace “Is it an 800 W product?” with a harder question:

> Which hardware and software configuration produces which maximum value, through which connection, under which instructions?

Level 3: Match the technical evidence to that configuration

Document collection is not document review.

For each report, certificate or declaration, check the model designation, hardware revision, tested accessories, operating modes, issue date, report owner, laboratory or issuing body, and exclusions. If a document covers a component rather than the complete system, label it as component evidence.

This is where apparently impressive files often lose their force. A certificate may be genuine and still be too narrow for a claim about the full installed use case. The Bochum material illustrates the gap: evidence relating to certification did not automatically answer a separate question about overload protection in the advertised configuration.

The distributor’s job is not to reinterpret a technical standard. It is to spot mismatches early enough to ask a qualified party the right question.

Level 4: Give every claim an evidence owner

Common category language is not automatically safe language. Treat each public claim as a release item with a minimum evidence set and a named reviewer.

Proposed claim	Evidence needed before release	If the file is incomplete
“Plug and play”	Exact connection scenario, complete user steps, registration and installation boundaries, reviewed instructions	Quarantine the phrase or describe the setup factually
“No electrician required”	Country-specific basis, exact permitted scenario, clear exceptions and user instructions	Do not publish a universal statement
“VDE/IEC compliant”	Named standard, report or certificate scope, exact model and revision, valid issuing details	State only the verified document fact
“Overload protection”	Identified function, operating limits, dependencies and verification method	Remove the protection claim until it is verified
“Compatible with existing balcony PV”	Supported interfaces and topology, power limits, meters, firmware and exclusions	Publish a bounded compatibility checklist

This table belongs in the same release workflow as the technical file. Marketing language is not a layer of polish added after product review. It is part of the reviewed product offer.

Level 5: Reopen the file when the product changes

The evidence ladder does not end when the listing goes live.

Firmware changes. Bundles change. Manuals are rewritten. A marketplace image can survive long after the included accessory has been replaced. Any of those changes may widen the gap between evidence and claim.

Keep a change log that answers four questions: what changed, which evidence remains applicable, which claims were reviewed again, and whether existing customers need updated instructions. Reopen the release decision when a change affects the energy path, selectable limits, protective functions, required meter, connection method or instructions.

Small change, big consequence. That is why revision control belongs in sales operations, not only in engineering.

A five-question stop/go check

Before listing or relisting a plug-in battery, ask:

Does the received unit match the declared SKU, hardware revision and bundle?
Is the intended German connection and operating configuration documented?
Do the reports and certificates cover that exact configuration?
Does every public claim stay inside the evidence scope?
Is there a process for firmware, bundle, manual and claim changes?

One “no” is enough to pause the affected claim or listing. Do not fill the gap with an assumption. Request the missing evidence, narrow the wording or hold the release.

A pause is not a verdict that the whole product is non-compliant. It is a controlled decision that the current file cannot yet support the current offer.

What to request from a supplier

A useful pre-listing file should contain:

- a revision-controlled SKU and configuration statement;

- current German manuals and connection instructions;

- declarations, reports and certificates, including scope pages;

- maximum selectable values and permitted operating modes;

- protective functions and the conditions they depend on;

- supported meters, inverters, accessories and software versions;

- an approved German-market claim list;

- hardware and firmware change-notification rules;

- an incident, corrective-action and after-sales contact route.

This is not paperwork for its own sake. It is the material a compliance specialist, electrician or legal reviewer needs in order to do useful work.

Four shortcuts that fail the evidence test

“German courts banned balcony batteries.” They did not. The reported decisions address specific products and claims.

“CE means the installation is safe.” CE marking and a country-specific connection assessment are not the same statement.

“The app is set to 800 W, so the product complies.” A selected setting may not describe the maximum selectable configuration, and the connection scenario still matters.

“Certified.” Certified to what, for which model, in which configuration and with which exclusions? Without those answers, the word gives a buyer very little usable information.

The commercial lesson

Good distributors do more than collect supplier PDFs. They maintain a traceable line from the unit in the box to the configuration in the manual, the evidence in the file and the words on the product page.

That line is part of product quality. It also makes sales teams faster: approved claims are clear, unsupported claims are visible, and supplier questions stop bouncing between departments.

The September court headlines will fade. The evidence ladder should remain.

FAQ

Did Germany ban all balcony batteries?

No. The available reports and the published Bochum decision concern specific products, operating scenarios and advertising claims. Comparable products may need review, but this is not a blanket product-category ban.

Is a certificate enough to approve a “plug and play” claim?

No. The certificate must match the exact model and revision. The claim must also reflect the complete connection scenario, required steps, operating limits and German market boundaries.

Why should firmware appear in an evidence file?

Firmware can affect selectable power, control behaviour, meter dependencies and protective functions. When it affects operation, the reviewed version belongs in the configuration record.