FAQ – Get answers to your questions

Below, you will find answers to a number of frequently asked questions about our batteries. To make it easier, we have divided our FAQ into questions and answers related to BAT-79 products and BAT-5/BAT-10 products.

If you have questions that you cannot find answers to here or elsewhere on the website, we would love to hear from you via our contact page.

BAT-79:

PRICE

How much does a BAT-79 solar cell battery cost?
Contact us for a specific offer based on your need for energy storage.

How big should my/our battery be?
It all depends on the size of the solar installation. For a housing association, a company, a school or similar organization, one or more 5/10 kWh batteries or 79kWh batteries might be the answer.

For how much of the year can you use a solar cell battery?
All year. On sunny days, the battery will be used for time shift, which means that you delay the consumption of the produced electricity.

What happens to the electricity you don’t use?
Initially, the battery will store the excess solar energy. If the battery is fully charged, the excess electricity will be sent out to the power grid.

Will my/our property increase in value with a solar battery?
The battery will ensure that the building uses less energy from the grid, which can make the building more attractive.

INSTALLATION

How much space does the battery take up?
BAT-79, Outdoor: H218cm x W85cm x D72cm/H85.83 in x W33.46 in x D28.34 in
BAT-79, Indoor: H190cm x W66cm x D66cm/H74.80 in x W25.98 in x D25.98 in
You can find data sheets with more details on the product page.

Can you install the battery yourself?
The battery must be installed by a XOLTA-approved, authorized electrician. The actual connection of the battery is simple. We have selected partners that cover all of Denmark. This helps ensure a quick installation.

Where to place your solar battery?
Our 79 kWh batteries are made as indoor and outdoor models. The model and location are decided in discussion with the user.

Can XOLTA batteries be installed with my/our existing solar cells?
Yes, XOLTA batteries can be used for all grid-connected solar installations.

What is the delivery time?
The delivery date will appear on your order confirmation. Delivery is usually 6-8 weeks from receipt of the order confirmation. For larger installations, delivery is agreed on a case-by-case basis.

Can I use my own electrician to install a BAT-79?
The installation must be carried out by a XOLTA-approved, authorized electrician.

Must the battery be connected to the Internet?
Yes, the battery must have a wired connection to the internet to ensure optimal operation.

Must the battery be placed right next to the electrical panel?
It doesn’t have to be. The optimal location is agreed upon with the installer.

Do I need a new meter if I get a battery?
For correct billing and full utilization of your new battery, you must ensure that your electricity meter is of the summation meter type. Contact your local network company for advice.

MAINTENANCE

Is maintenance required on a solar cell battery?
Yes, the battery must be serviced regularly. We offer a service agreement which ensures that the battery is monitored and regularly inspected, so that the warranty is maintained.

Can a XOLTA solar cell battery withstand the Danish climate when placed outside?
Yes, it can. The battery is fully functional in the Danish climate.

ABOUT BATTERIES

Is a XOLTA solar cell battery safe?
Yes, the batteries comply with current CE standards. We use a BMS of the highest class and all our battery solutions can be installed outdoors.

What does BMS mean?
BMS means Battery Management System. When managed well during charging and discharging, Li-ion offers far more benefits than other battery chemistries. More capacity, longer lifetime, faster charging, lower costs and better temperature tolerance.

All XOLTA batteries contain BMS from Lithium Balance, one of the world’s leading BMS suppliers.

What type of battery do you use?
Our BAT-79 indoor/outdoor batteries use NMC battery cells.

How often should the batteries be replaced?
The battery has a life expectancy of over 15 years.

OPERATION

Does the battery use a large part of the produced electricity to run?
The XOLTA battery systems are very efficient, which means low energy loss. See product page for BAT-79 product details.

Can I/we achieve full independence from the grid if I/we have one or more solar cell batteries?
In principle, yes, but it will not be economically optimal due to the long winter season in Denmark.

How can I/we keep up with electricity production and consumption?
In the XOLTA app, you can always see how much your solar cells produce and how much of your energy consumption is covered by the sun and the battery. You can also read how much money and how much CO2 you save.

BAT-5 AND BAT-10 COMPACT BATTERY

PRICE

How much does a XOLTA compact solar battery cost?
The price for BAT-5 is DKK 39,495, incl. VAT
The price for BAT-10 is DKK 59,495, incl. VAT

What is the payback time on a solar cell battery?
It depends on the size of the solar installation compared to consumption, but the payback time is approx. 10 years.

How big should my/our battery be?
It all depends on the size of the solar installation. For a typical Danish house and its solar installation of 4-6 kWh, a battery of 5 kWh will be a suitable size. But if you want to ensure the greatest possible degree of self-sufficiency, you should choose a battery size of 10 kWh.

What part of the year can you use a solar cell battery?
All year. On sunny days, the battery will be used for time shift, which means that you delay the consumption of the produced electricity.

What happens to the power you do not use?
Initially, the battery will store the excess solar energy. If the battery is fully charged, the excess electricity will be sent out to the power grid.

Will my/our house increase in value with a solar cell battery?
The battery will ensure that the house uses less energy from the grid and can therefore make the house more attractive.

DELIVERY AND INSTALLATION

How much space does a battery take up?
BAT-5, Compact: H: 77.2cm x W66.45cm x D25.95cm
BAT-10, Compact: H: 77.2cm x W66.45cm x D25.95cm

Can you install the battery yourself?
The battery must be installed by a XOLTA-approved, authorized electrician. The process is easy, as we have selected partners that cover the whole of Denmark. It helps ensure a quick installation.

Where to place your solar battery?
A solar cell battery should preferably be placed outside and optimally on a north- or east-facing wall or in a carport.

Can a battery be placed inside?
It is not recommended to place batteries in the residential area of the building.

Can XOLTA batteries be installed with my/our existing solar installation?
Yes, XOLTA batteries can be used for all grid-connected solar systems.

What is the delivery time?
Typically, there is a delivery time of 4-6 weeks. This will be explained when ordering.

How long does it take to install?
The installation takes about one working day and must be carried out by an authorized electrician.

Can I use my own electrician to install the battery?
The installation must be carried out by a XOLTA-approved, authorized electrician.

How is the battery connected to an existing solar system?
The battery is connected directly to your electrical panel. Excess electricity is stored in the battery for later use.

How much space should there be in my electrical panel?
There must be a minimum of 167 mm free space in the electrical panel.

What do I do with my existing solar inverter if I buy a battery with a built-in inverter?
The battery is installed independently of your solar cell installation, so no changes need to be made.

Should the battery be connected to the Internet?
Yes, to ensure optimal operation, the battery must be connected to the Internet via cable.

Why can’t I connect the battery to the internet wirelessly?
Unfortunately, wireless internet is not stable enough to supply data to the battery. Therefore, the internet connection must be hard-wired.

Should the battery be right next to the main meter?
It does not need to be. You can discuss the optimal location with the installer.

Do I need a new meter if I get a battery?
For correct billing and full utilization of your new battery, you must ensure that your electricity meter is of the summation meter type. Contact your local network company for advice.

MAINTENANCE

Is there maintenance on a solar cell battery?
There must be free ventilation around the battery, but otherwise nothing else is required. All XOLTA batteries are connected to the Internet and operation is monitored around the clock.

Can a XOLTA solar cell battery withstand the Danish climate?
Yes, it can. XOLTA batteries are fully functional in the Danish climate. Read more about how we test the batteries here.

Can I sign a service agreement on my battery?
Yes, if you buy our Peace-of-Mind agreement when you buy your battery, you will be guaranteed 10 years of security. Read the details here

ABOUT BATTERIES

Is a XOLTA solar cell battery safe?
Yes, the batteries comply with current CE standards. We use a BMS of the highest class and all our battery solutions can be installed outdoors.

What does BMS mean?
BMS means Battery Management System. When managed well during charging and discharging, Li-ion offers far more benefits than other battery chemistries. More capacity, longer lifetime, faster charging, lower costs and better temperature tolerance. All XOLTA batteries contain BMS from Lithium Balance, one of the world’s leading BMS suppliers.

What type of battery do you use?
BAT-5 and BAT-10 use LFP battery cells.

How many phases does the battery inverter have?
The battery inverter is a single-phase inverter with a power of 3.6kW. However, it compensates in all three phases.

Can you get a battery with a 3-phase inverter?
A 3-phase system is achieved by interconnecting 3 systems with 3 times greater capacity and power.

How often should the batteries be replaced?
The battery has a life expectancy of over 15 years.

How does the battery know it needs to charge?
The part of solar cell production that is not used directly in the household is transferred to the battery. Technically, we install a meter at the grid connection point that sends a signal to the battery to charge if power runs out on the grid. This meter is included with the battery when ordered.

How long does a battery charge last?
The battery can, in principle, hold the charge for months, but economically it is most advantageous to run continuous charges and discharges, preferably from day to day.

Can the batteries be used for off-grid systems?
The batteries cannot currently be used for an off-grid system, but we expect an off-grid version to be released in 2022.

Can you charge the batteries with cheap power from the grid at night?
We are working on this feature and hope for it to be part of the standard functionality for a XOLTA battery soon.

Are the batteries environmentally friendly?
Lithium-ion batteries are significantly more environmentally friendly than other types of batteries. This is partly due to the fact that they can store more energy, are smaller and last much longer than lithium, NiMH and NiCD batteries for example. Therefore, you use far fewer Li-ion batteries compared to other battery technologies. Li-ion batteries also have less energy loss which helps to make them more environmentally friendly. Finally, Li-ion battery technology is still new, and therefore has a much greater potential for continued development and reduction of environmental impact. For example, it is well on its way to eliminating the use of cobalt and greatly reducing CO2 consumption during manufacturing. In contrast, existing battery technologies have largely exhausted their potential for improvement. This applies to the battery industry in general, where they have succeeded globally in a very high degree of recycling, and this also applies to Li-ion batteries, with some operators promising up to 95% recycling of the materials used.

OPERATION

Does the battery use a large part of the produced electricity to run?
XOLTA battery systems are very efficient, which means low energy loss. See product page for BAT-5 and BAT-10.

Can I/we achieve full independence from the electricity grid if I/we have one or more solar cell batteries?
In principle, yes, but it will not be economically optimal due to the long winter season in Denmark. On many summer days in Denmark, however, you will experience 100% self-sufficiency.

How can I/we monitor the electricity production and consumption?
In the XOLTA app, you can always see how much your solar cells produce and how much of your energy consumption is covered by the sun and the battery. You can also read how much money and how much CO2 you save.