« Devis clair, sans surprise, primes comprises. Un seul interlocuteur du début à la fin. Je recommande sans hésiter pour le photovoltaïque. »
Pierre M.Tournai
Solar panels · Storage
Battery for solar panels: use your own energy, even at night
Without a battery, your panels’ surplus is fed back to the grid at a low price. A home battery stores the energy produced during the day and releases it in the evening and at night — you raise your self-consumption and gain independence when outages hit.
- 5 → 15 kWh
- common capacities
- ~6,000
- charge cycles
- 10 years
- typical warranty
up to 80%self-consumption
Outage backupbackup option
Technical specifications
What a home battery is really worth
The figures that matter for quality solar storage, sized and installed by our teams. Concrete benchmarks, not marketing.
- Usable capacity 5–15 kWh
Capacity is sized to your evening consumption and the size of your installation. For a household, 5 to 10 kWh covers most evenings.
- Lifespan ~6,000 cycles
A LiFePO4 lithium battery handles around 6,000 charge/discharge cycles — well over ten years of daily use, while keeping most of its capacity.
- Efficiency 90–95 %
Round-trip efficiency (energy out versus energy stored) reaches 90 to 95% on recent lithium batteries — very few losses between charge and discharge.
- Depth of discharge 95–100 %
LiFePO4 discharges almost completely without damage, where older technologies were limited to 50%. The full rated capacity is genuinely usable.
- Backup Optional
With a hybrid inverter and the backup function, the battery powers your priority circuits during a grid outage — lighting, fridge, internet router.
- Safety & chemistry LiFePO4
Lithium iron phosphate chemistry is the most thermally stable for home use. The built-in BMS continuously monitors temperature, voltage and charge.
* Indicative values for mainstream lithium batteries. Real-world performance depends on the model and sizing — confirmed during the survey.
In full transparency
Storage: benefits & limits
A battery doesn’t make the same sense for everyone. Here, honestly, is where it changes the game and where it deserves a second thought.
Where it shines
- More self-consumptionUse the energy produced during the day in the evening, instead of selling it cheaply.
- Independence and backupWith the backup option, you keep the power on during grid outages.
- Less exposed to tariffsLess sensitive to electricity price swings and to the prosumer tariff.
- ScalableMost batteries can be expanded module by module as your needs grow.
What you should know
- An investment to recoupPayback depends on your consumption profile and the injection tariff.
- Sizing is keyA battery that’s too large never fills up; too small and it saturates quickly.
- Space and locationA ventilated, frost-free wall is needed (garage, utility room, dry cellar).
- Not for every profileIf you mainly consume during the day, the gain can be limited.
For which profile
Is a battery right for you?
It all comes down to when you consume. A few profiles where storage is especially worthwhile:
-
Heavy evening consumer
If most of your consumption falls in the evening and at night, the battery stores the day’s solar production to release it when you need it.
-
Need backup during outages
To secure essential circuits (fridge, freezer, internet, lighting) during outages, the backup option takes over in a fraction of a second.
-
Reduce the impact of the prosumer tariff
Where injection is poorly valued, self-consuming your surplus through a battery protects the payback of your photovoltaic installation.
Physical battery or virtual battery?
A physical battery actually stores your energy; a virtual battery is a grid-based offsetting service. We compare the two against your profile, and size everything with the right lithium battery.
Glissez la poignée pour comparer
Real case · photovoltaic home, Walloon Brabant
Midday surplus used in the evening, self-consumption soaring
A 6 kWp installation that was injecting half its production to the grid for a few cents. We added a 10 kWh battery with a hybrid inverter and backup function: the midday production now powers the evenings, and priority circuits stay on during outages.
- +38 ptsself-consumption
- 10 kWhstored every day
- Backupon key circuits
Customer reviews
They chose wendows
5.0/5 · 1verified reviews
Compare storage options
Physical battery, virtual, or nothing?
Store physically, subscribe to a virtual battery, or inject without storage: three strategies with different logics. Here’s how they compare.
| Critère | Physical batteryVous êtes ici | Virtual batteryVoir la gamme → | No storageVoir la gamme → |
|---|---|---|---|
| Self-consumption | Strong increase | Indirect (offsetting) | Limited to real time |
| Backup during outages | Yes, with backup | No | No |
| Investment | €€€ — hardware | € — subscription | None |
| Grid independence | The highest | Grid-dependent | Fully dependent |
| Recurring costs | Near zero | Monthly subscription | Prosumer tariff |
| Lifespan | ~6,000 cycles | Contractual service | — |
| Ideal for | Evening use, seeking independence | Smoothed use, no hardware | Small install, daytime use |
Indicative benchmarks. The best choice depends on your consumption profile and the current tariff — we fine-tune it together at the survey.
- the tech
LiFePO4 lithium battery
The reference chemistry for home storage: stable, durable and fully dischargeable. The heart of your battery.
All about lithium → - the hardware
Hybrid inverter
The hybrid inverter manages panels, battery and grid, and unlocks the backup function. The centrepiece of storage.
See the hybrid inverter → - to pair with
Solar kit
A battery only makes sense with good production. Discover our panel kits sized for storage.
See the solar kits → - budget
Price & payback
How much an installed battery costs and how long it takes to pay off based on your consumption.
See the prices → - the hub
Storage & batteries
Our full home storage offering: technologies, brands and sizing in one place.
See storage → - ↑ category
All things photovoltaic
An overview of our solar panels in Belgium: production, inverters, batteries and incentives on one page.
Back to the solar guide →
Indicative price 2026
How much does a solar battery cost?
The price depends on the capacity, the brand and whether a hybrid inverter is included. Here are some benchmarks for installed hardware, before any incentives.
See storage prices & payback →* Indicative ranges for installed hardware. Payback depends on your consumption profile — costed during your free quote.
- 5 kWh battery from €4,000installed, excluding hybrid inverter
- 10 kWh battery €6,500–9,000with hybrid inverter
- Backup option + €500–1,500backup during grid outages
- Reduced VAT 6%for renovation (home > 10 years old)
Solar battery FAQ
Your questions about storage
Is a battery worth it in 2026? +
It depends on your profile. The more you consume in the evening and the lower the injection tariff, the more attractive a battery becomes: it avoids selling cheaply energy you would buy back at a higher price. We cost your real case in the quote, based on your consumption.
What battery capacity do I need? +
We size it to your evening consumption and the size of your installation. A battery that’s too large never fully charges; too small and it saturates before nightfall. For a household, 5 to 10 kWh generally covers most evenings.
Do we keep power during an outage? +
Only with the backup option and a compatible hybrid inverter. In that case, the battery switches over in a fraction of a second to your priority circuits (fridge, lighting, internet). Without this option, a standard battery shuts down safely during a grid outage.
Can a battery be added to an existing installation? +
Yes, in most cases. Depending on your current inverter, we add a compatible battery or replace the inverter with a hybrid model. We check your installation’s compatibility before proposing the most economical solution.
How long does a home battery last? +
A LiFePO4 lithium battery handles around 6,000 charge/discharge cycles — well over ten years at one cycle per day. It’s typically warranted for about ten years, keeping most of its capacity at the end of the warranty.
Physical battery or virtual battery? +
A physical battery actually stores your energy at home and enables backup during outages. A virtual battery is a grid-based offsetting service, with no hardware and no independence. The right choice depends on your profile and the tariff; we compare them together.
Get your free solar battery quote within 48h
Analysis of your consumption profile, precise sizing, verified incentives. Describe your project in under a minute.
- Free and no obligation
- Sized to your actual consumption
- Installed by our certified fitters