What warranty and maintenance does a business battery need?

A business battery should come with three things in writing. A warranty that states what share of the capacity is guaranteed, for how many years or cycles, and under which conditions. Remote monitoring that warns someone when something goes wrong. And a named party that maintains and repairs the system, now and in ten years. When you choose a business battery, weigh these terms as heavily as the price per kWh.

Maybe you are comparing offers and every supplier writes "10 years warranty". Or you already have a battery, and the company that installed it no longer answers the phone. On forums, business owners describe the same moments. The installer came once, changed a few settings, and later blamed "user error". The app stopped working when the supplier went bankrupt, and the owner was left with "200 kilos of old iron".

What most buyers do not see is where the warranty really sits. It is rarely in the headline number. It is in the conditions: the temperature of the room, the number of cycles, a registration deadline, a software update you did not allow. Miss one, and a ten-year warranty can shrink to two years or disappear. A battery that nobody monitors can also age for months before anyone notices.

Take a look at the semi off-grid system in Wingene: 150.4 kWh of storage with a 10-year warranty. The solar panels are actively monitored, consumption and yield are visible at a glance, and the control is open source.

What does a business battery warranty cover?

A business battery warranty usually covers two things: defects in the product, and the capacity the battery keeps over time. The installation work is a third layer, and it comes from your installer, not from the manufacturer.

A real warranty text shows how this works. SMA publishes the warranty conditions of its commercial storage systems STORAGE-30-20 and STORAGE-50-20, which also apply in Belgium. SMA guarantees at least 70% of the nominal capacity. The warranty starts at two years. It grows to ten years only if you register the system within 30 days of commissioning. You must also allow critical software updates and keep the system online for at least 10 consecutive hours a week. The signed commissioning report must also be completed within 30 days and kept.

So the same battery can come with two years or ten years of warranty, depending on paperwork and an internet connection. Remote monitoring keeps a system online, but the registration and the commissioning report are steps someone has to plan.

Why temperature and cycles decide the capacity warranty

The capacity warranty ends at a number of years or a number of full cycles, whichever comes first. A full cycle is charging and discharging the whole capacity once. Two half cycles count as one full cycle.

In the SMA conditions, the number of cycles guaranteed depends on the room temperature and on how hard the battery is charged and discharged. The C-rate (the charge or discharge power compared with the capacity) is that measure. A C-rate of 0.5 means the battery is fully charged or emptied in about two hours.

Other brands use other numbers, but the pattern is the same. DNV, the testing and certification company, lists what capacity warranties typically depend on: cycles or throughput, temperature, state of charge and C-rate. Its advice is to check how capacity is measured and which operating limits the warranty imposes.

Does a company get the two-year legal guarantee on a battery?

No. In Belgium, the two-year legal guarantee only applies when a business sells goods to a consumer. The FPS Economy states it plainly: if you bought a device for your professional activity, you cannot rely on the legal guarantee for consumers.

A professional buyer keeps the protection against hidden defects and any commercial guarantee the seller or manufacturer gives. For a company, the warranty text and the service agreement are the protection. That is why it pays to read them before you sign, not when something breaks.

What maintenance does a business battery system need?

A lithium iron phosphate (LFP) battery needs almost no maintenance of its own, but the system around it does. There is no water to top up, as with lead-acid. The work is in the connections, the room, the software and the inspections.

Pylontech, the brand of the lithium battery in our off-grid case, gives more detail in the operation manual of its US3000C module. A module that is stored for a long time must be recharged to at least 90% every six months. The optimal operating temperature is 10 to 40 °C.

The rules around the battery (environmental conditions, fire service, battery room) are a topic of their own. Want to know which apply to your site? Then read our guide on whether a business battery is safe.

How long does a business battery last, and what does the warranty promise at the end?

A business battery lasts as long as its cycles and its room allow: the warranty tells you the minimum the manufacturer dares to promise. The Pylontech lithium battery in our off-grid case carries a 10-year warranty on 80% of its capacity. Our home batteries come with a 10-year warranty on retained power.

Capacity does not drop in a straight line. DNV warns that degradation curves differ widely between cell types. A project that must run longer than its warranty needs a plan: extra modules or replacement later. A battery that shaves peaks every day also ages faster than one that waits for a power cut.

Our guide on battery storage for businesses explains what a BESS is made of and how to size it. Here the point is simpler. Ask for the end-of-warranty capacity in writing, as a percentage, with the years and the cycles or MWh next to it.

Why is remote monitoring part of the service of a business battery?

Remote monitoring finds a problem before it becomes a failure. And its data is what you need when you make a warranty claim. Without it, a battery can lose capacity or trip for weeks before anyone notices.

Our high-power business battery installations, modular up to 1 MW, include monitoring, control and optimisation. After installation you follow the whole system in real time in the app and the VRM portal. You see consumption, yield and the live state of the battery. You can set a notification for a low battery level, follow consumption per phase, and look back at any minute, hour or day.

VRM (Victron Remote Monitoring) is free, according to Victron. It lets you set alerts, control a system remotely as if you stood in front of it, and update Victron products from the portal. That means many faults can be diagnosed, and some solved, without a technician driving out.

The data matters for the claim too. The SMA conditions oblige the owner to give access to the battery log and the temperature data within 7 working days of a claim. Remote access to the monitoring is required too. DNV advises that the owner, or a neutral third party, keeps the battery data for the whole project life.

Monitoring also helps before the battery is bought. For a garden contractor in Zele, we first measured average and peak consumption for a month. Then we matched the number of solar panels to the real use.

What if your battery installer disappears?

Then three things decide what happens next: can you claim from the manufacturer yourself, is the system open, and who owns the monitoring account? Check them before you sign, because afterwards it is too late.

We also maintain and repair battery systems that were installed by others. Our team includes three certified battery specialists. We connect new batteries and revise existing ones, so an orphaned system is not automatically a write-off. Read more about maintenance and repairs of existing battery systems.

What should a service agreement for a business battery include?

A good service agreement says who watches the system, who reacts, how fast, and what it costs when it is not a warranty case. Use these questions as your checklist.

• Monitoring: is the system monitored remotely, who gets the alarms, and at which thresholds (temperature, low battery, faults)?
• Response: within which time does someone react to an alarm, and within which time is someone on site if needed?
• Yearly check: what exactly is checked (connections, temperature, firmware, back-up test), and do you get a report?
• Software: who installs firmware updates, and are critical updates enabled as the warranty may require?
• Costs outside warranty: what does a visit cost when the fault is not covered? SMA, for example, charges 95 euro per hour plus travel if an assessment finds no warranty case.
• Documents: who keeps the commissioning report, the serial numbers and the maintenance reports that a warranty claim needs?
• End of life: who takes the battery back, and where does it go?

What service do you get with a battery from us?

We stand for a quality installation with excellent service, and we stay involved after commissioning. The steps are the same for every business battery.

1. Step 1: Analysis and sizing. If data is missing, we can monitor your consumption for a short period first.
2. Step 2: Technical design, matched to your consumption, production and future plans.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and support. You follow the system in the app and the VRM portal, and the system can be monitored and controlled remotely.

Our home batteries come with a 10-year warranty on retained power. The Pylontech lithium battery in our off-grid case has a 10-year warranty on 80% of its capacity. The semi off-grid project in Wingene came with a 10-year warranty. The exact terms for your business battery are in your offer.

Is a battery at the end of its life? Our battery recycling screens lithium batteries and gives the ones that are still fit a second life.