Cooperation between an electrician and a battery specialist works when the split is written before the quote. You keep board, cabling, earthing and protections, and the specialist sizes, sets up and commissions the business battery or home battery. Agree who draws the diagram, books the inspection, notifies Fluvius or ORES and takes the first call.
On your production hall, farm shed or villa, the customer now wants a three-phase battery with back-up, heat pump and two electric cars. A Reddit electrician admitted he had never installed one, and his inspectors had no answers.
In Peer our customer was an electrician himself; our battery know-how gave a fine finish. The whole house is on no-break, single-phase, 5 kVA and 15.4 kWh.
Why would an electrician bring in a battery specialist?
When the battery must do more than store solar power: back-up, peak shaving, three-phase loads or island mode. Those jobs are won or lost in the sizing and the settings, not in the cabling.
The board, protections, earthing and AC cable runs are yours. The specialist sizes on quarter-hour data (the power use per 15 minutes that sets the capacity tariff). Grid-code settings, battery communication, the changeover to back-up and the follow-up six months later are his too.
On r/electricians, one wrote that too many electricians only know how to upgrade a panel. The heart of a quality electrical room, he added, is now a hybrid inverter. The specialist should add what you do not do every week, not take over what you do every day.
The goal decides the design. A lower monthly peak needs a lot of power briefly; a site running through a cut needs energy for hours. A premium home with heat pump, cars and pool needs full back-up with a three-phase home battery.
The risk is the gap between two trades that nobody owns. On a Flemish forum, the solar installer, charger installer and Fluvius blamed each other for a failing inverter. The inspector waited until all worked and the charger bill stayed unpaid; on a business site, that gap costs you the customer.
Which set-ups exist for electrician and battery specialist cooperation?
Three set-ups are common: your battery installer partner works for you, the customer hires you both, or you work for the specialist. Each works, as long as everyone knows who answers to the customer.
| Set-up | Who contracts the customer | Strong point | Watch out |
|---|---|---|---|
| 1. Specialist as your subcontractor | You, for the whole job | One face to the customer; you keep the relationship | You answer for the battery part too; get the specialist's warranty terms in writing |
| 2. Two contracts, side by side | The customer signs with both | Each party answers for its own work | The interfaces (board, diagram, inspection) fall between two contracts |
| 3. You as subcontractor of the specialist | The battery specialist | The specialist answers for the design and the battery | Agree your scope and who books the inspection |
On a business site, set-up 1 or 3 is usually clearest, because one party carries the result. Set-up 2 works when both follow one plan and one diagram. Write the set-up in the quote, not in an email after the job.
Our article on how a business compares battery quotes lists what your customer will ask, so you can answer it first.
Who does what when you subcontract a battery installation?
Give every task one name before work starts. Tasks without a name are the ones that delay the inspection.
| Task | Usually | Agree in writing |
|---|---|---|
| Consumption data or a measurement on site | Specialist, with your access to the board | Which period, which meter |
| Sizing (kW and usable kWh) and choice of inverter | Specialist | Goal: peak, solar, back-up, charging |
| Placement and room (fire, ventilation, access) | Both | Who checks the room against the rules |
| Board, protections, earthing, AC cable runs | Electrician | Breaker sizes and cable sections from the design |
| DC cabling battery to inverter, battery communication | Specialist | Who supplies the cables and lugs |
| Back-up circuits and changeover | Both | Which circuits, and who wires the back-up board |
| Inverter settings, grid code, control software | Specialist | Who changes settings later |
| Single-line diagram of the whole installation | Electrician, with the specialist's part | One version, one owner |
| AREI inspection | Main contractor | Who books it, who is present |
| Notification to Fluvius or ORES | Main contractor or owner | Who files it and when |
| Handover, monitoring access, first call | Both | Who the customer phones |
A battery job in six steps
The full timeline, from measurement to commissioning, is in the steps of a business battery project. Placement rules, the fire service and your customer's insurer are covered in whether a business battery is safe.
Who draws the diagram, who inspects the battery installation and who notifies Fluvius?
The specialist designs the battery part; the electrician keeps one single-line diagram of the whole installation. The grid operator and the inspector read that one diagram.
For the notification Fluvius asks a valid AREI inspection (the Belgian electrical safety code) and a clear single-line diagram of the battery. The inverter must be on the Synergrid list of approved inverters (C10/26). A business storage system up to 25 kVA is notified in Mijn Fluvius; larger systems go through a grid study.
Synergrid's C10/11 treats a grid-connected battery that feeds back as a production unit, and phase imbalance may never exceed 5 kVA. So the specialist must see your board and existing inverters before choosing a battery. For an SMA or SolarEdge system, read how to add a battery and back-up to an existing installation.
Watch out
Flanders only: the Fluvius rules above. In Wallonia, a new production installation, including a battery, is declared to ORES. The AREI inspection before use applies in every region.
An approved inspection body checks the whole installation and declares it conform before use, so whoever books it must know both parts are ready. A business site is inspected again every five years. The AREI chapter on batteries in non-household installations puts large units in a battery cabinet or dedicated electrical room, with the right markings.
On Tweakers, a Flemish owner failed his first inspection on a missing limiting breaker and had to book a re-inspection. Walk through the installation together before the inspector comes, diagram in hand.
Fluvius accepts a notification by the owner or the installer, so pick one name. According to Fluvius, adding only an extra battery module needs no new inspection, but a new inverter needs a new notification.
How do you split the battery warranty and after-sales?
In three parts: the manufacturer covers the equipment, each party guarantees its own work, and the customer gets one agreed first call.
SMA's storage warranty, for example, runs two years and becomes ten if the system is registered within 30 days with a commissioning report. The buyer who commissioned it files the claim, and changes without SMA's approval are excluded. Agree who registers the system and keeps the report.
For a home, the Belgian two-year legal guarantee applies to the sale to the consumer, who turns to the party that sold to him. A business customer has no legal guarantee, so the contract says it all. Our article on warranty, service and maintenance of a business battery explains what to put in it.
Agree who holds the monitoring account and whether you and the customer both get access. Electricians complain about battery cabinets with 'warranty void if modified' labels on the terminals; agree who may touch what. Our monitoring software shows consumption per phase and sends alerts, so the specialist often sees a fault before anyone drives out.
What should you agree in writing before the job starts?
Seven points, in the quote or a short cooperation note the customer also sees.
Scope per party
Tasks and materials per party, from the task table above.
Main contractor and invoice
Who signs with the customer, who invoices whom, who answers if something goes wrong.
Design and diagram
Who sizes, who draws, who approves changes during the works.
Inspection and notification
Who books the AREI inspection, who attends, who notifies Fluvius or ORES.
Warranty and claims
Who registers the equipment, keeps the commissioning report and files a claim.
Monitoring and data
Who holds the portal account, who gets access, and whether the customer keeps it if a party leaves.
First call and repairs
Who the customer phones, how a fault is passed on, who pays a call-out that was the other trade's.
Tip
Use the same seven points on every job with the same specialist. After two or three jobs the note is a template and the quote goes out faster.
A battery job on the table and not sure how to split it? Call us.
When do you not need a battery specialist?
Not for a simple home battery without back-up, from a brand you are trained on, with an inverter on the Synergrid list. Brand training and the manufacturer's manual do the job.
You can do it alone
- Only stores solar power
- No back-up circuits
- A brand you are trained and registered for
- One inverter, a clear phase set-up
Bring in a specialist
- Back-up or full no-break
- Three-phase with heat pump, cars or pool
- Peak shaving
- Off-grid, semi off-grid or a generator
- Several inverters or an existing battery to revise
Our verdict
A specialist who tells you a job is simple enough to do yourself is worth more than one who always wants the whole job. Ask that question at the start.
Frequently asked questions
Who may install a battery in Belgium?
The law checks the result: an approved inspection body must declare the installation conform under the AREI before use. Fluvius advises owners to be helped by a professional or their installer.
Is there a certificate for battery installers in Belgium?
RESCert, the Belgian certification for renewable energy installers, covers solar panels and heat pumps among others, but lists no battery category. Brand training, often the only battery certificate there is, and courses like the Syntra battery training are the usual proof of skill.
Can a specialist revise a battery that another installer placed?
Often yes. Check the manufacturer's warranty terms first, because changes without approval can end the warranty.
Does a back-up home battery need a specialist?
Not always, but back-up adds a changeover, a back-up board and choices about which circuits stay on. Our guide to a home battery with back-up power explains the options.
Want to bring us in on a battery job?
We take the battery part from data to commissioning. Our business battery page calls it full integration with the existing electrical infrastructure.
- Step 1: Send us the basics. The single-line diagram or a photo of the board, the connection size, the existing inverters and the loads the customer wants on back-up.
- Step 2: Analysis and sizing. We take measurements first where data is missing.
- Step 3: Technical design. The battery part, based on the customer's consumption, production and future plans.
- Step 4: Installation and commissioning of the battery system.
- Step 5: Monitoring and support after delivery. We tell you which part we take on, and what stays with you.
Our team includes three certified battery experts, and members took the Syntra battery specialist training (in Dutch). We connect almost all inverter types to a home battery, revise existing batteries and maintain and repair installed systems, as a Victron Energy Certified Partner.
We build business battery systems up to modular installations of 1 MW, and home batteries with back-up for large homes.
Sources
- Fluvius: home battery, notification, AREI inspection and single-line diagram (NL)
- Fluvius: register a storage system (NL)
- FPS Economy: inspection of non-household electrical installations (FR)
- Synergrid C10/11, edition 2.4 (NL)
- ORES: new energy production installation (FR)
- RESCert: certified installers of renewable energy (NL)
- SMA: warranty conditions for storage systems
- FPS Economy: legal guarantee, frequently asked questions (NL)