Marstek Saturn C - B2500

Q: How does a storage system for my plugin solar kit work?

In short: as easy as a plugin solar kit.There are different types of storage systems, can be divided into these main categories:Storage for already installed plugin solar kits. If you already have a plugin solar kit with solar panels and a micro inverter installed, you can add a storage system between your solar panels and the micro inverter. These systems are generally very easy to install, and in some cases (like the Saturn C B2500) even expandable in a modular way.All-in-one storage systems. If you want to add storage to your first plugin solar kit, an all-in-one solution is best. These systems combine batteries, controllers and micro inverters into a single system. You plug the solar panels in on one side, and connect the system straight to your home socket on the other.Standalone storage systems. Recently a third category of storage systems has launched, that doesn’t need a direct connection to your solar panels or plugin solar kit. These independent storage systems connect to any household plug, and store all surplus power your solar kit produces. They charge and discharge through your home’s electricity network, and can also be charged with grid energy if you want to top up in low-cost times or have no solar installed at all.

Q: Can I also charge my storage with power from the grid?

In short: with a hybrid storage system, yes.Most storage systems that have launched in recent months include “hybrid” charging. This means that the storage system can not only discharge into the home’s power network, but also charge from it. This functionality allows you to top up your battery with power from the grid. This makes sense if your power tariff has very cheap prices in some dayparts, when topping up costs little, and use that power in the more expensive dayparts.

Q: How much storage do I need for my home?

In short: this depends on your consumption levels.Storage needs can be looked at from several sides:Solar kit production. If you look at how much your solar kit produces during an entire day, and how much you consume on the spot, the rest is what you will have to store. For example, if your Plus 2000 kit produces 8 kWh per day but during the day you only use 3 kWh, then you need at least 5 kWh of storage for your surplus, to use it when the sun doesn’t shine.Household demand. If you know how much you consume per day at home after subtracting the immediate consumption of your solar kit’s production, you know what you're missing. A part of that can be covered by storing your solar kit’s surplus. The rest can be covered by charging in low-cost hours from the grid. For example, if you consume 10 kWh per day in the above example, you will need 2 kWh to charge from the grid on top of the 5 kWh mentioned above.And remember, that when it comes to batteries, you should never discharge below 10% and never charge over 90%. This means that you can only use 80% of any battery capacity. This would mean that in the above scenario of 7 kWh of required storage, you will need a storage system of 9 kWh, whose 80%-capacity of 7,2 kWh covers your needs.

Q: Will a storage system also work during power outages?

In short: Some of them do.Several storage systems that have launched recently have an “AC outlet”, also known as “emergency outlet” or “anti-blackout”. This is a Schuko socket that delivers electricity when the network goes down. These systems can also be used in homes that are not grid connected.During power outages, like the “apagón” in Spain, Portugal and parts of France in April 2025, these systems provide critical base power to their customers, literally “keeping the lights on”. With sufficient storage capacity, and daily recharge with your solar kit, you can easily get through power outages also for longer periods of time.

€698,00

€798,00

Promo -20%(Saturn C + SM + Performance 800) Code: SATURN800

Free shipping in mainland Spain, Portugal and Balearic Islands.

The Marstek Saturn C – B2500 is a smart plug & play battery designed to enhance any balcony solar kit.

With 2.24 kWh of capacity and up to 800 W output, it stores solar energy, lowers your electricity bills, and powers key appliances even after sunset.

Use it with or without a smart meter. The choice is yours.

Plug the battery into your solar setup
Connect the Saturn C to your microinverter using standard MC4 connectors.
Connect the battery to the Marstek app
Download the Marstek app and pair your battery. This gives you full access to real-time monitoring and control.
Choose how to manage energy use
Select your preferred usage mode in the app:
- Manual: Set your usage schedule manually.
- Smart meter (optional): Enable intelligent energy storage based on live consumption data.
Monitor and control via app
Track charge status, set energy usage preferences, and view savings. All from your phone.
Power your essentials after dark
The Saturn C delivers up to 800 W output, enough to run lights, a router, and other key devices using stored solar energy at night.

Smart Meter:

With Without

Variant

Questions? Call or text +34 640 91 31 51

Easy and secure payment

Power through nights

Stay powered even when the sun goes down

Store your extra solar power

Save unused solar energy for later use

Use at least 6,000 times

Engineered for long-term performance

Store unused solar energy all day long

During daylight hours, the Marstek Saturn C stores every bit of solar power your kit produces and you don’t immediately use. Instead of sending it to the grid, the battery stores the surplus energy, ensuring nothing goes to waste.

Enjoy your stored power after dark

As soon as the sun goes down, the stored energy is released, keeping your essential devices running through the night. The micro inverter seamlessly delivers this stored electricity back to your household circuits.

Quick and easy installation

The Marstek Saturn C can be installed by simply connecting your solar panels to the Marstek battery and the Marstek battery to the microinverter.

The installation doesn't require more than a few minutes, as you don't need to modify your electrical system.

Enjoy solar energy 24/7

Use an existing or new solar kit

Already have a solar kit? Great. If not, pick the one that fits your space: rooftop, balcony, or garden, it doesn’t matter.

Connect the battery

Connect the Saturn C - B2500 to your solar kit. That’s it. Charging and discharging happen automatically: no tools, no technician.

Track and optimize your energy

Use the app to monitor your solar production, adjust charging times, and maximize your energy savings with just a few taps.

Plugin solar kit Installations of Robinsun customers

What our customers say about us

Daniel

Excellent service

The entire process went smoothly. The website is simple and effective. The payment process was transparent and seamless. The shipment was on time, although the carrier split it into two packages with only one tracking number, which caused some confusion for me, but this was quickly clarified by Robinsun's customer service.

Nov 11, 2025

Performance 400

Rafael

Excellent customer service

Excellent customer service, fast shipping and quality product at a good price.

Nov 11, 2025

Marstek Venus E 3.0 - 5.12 kWh

Jose Antonio Granero Miralles

Everything perfect

The personal service over the phone was outstanding. There was a problem with the agency, and they resolved it quickly. I will work with them again and recommend them.

Nov 11, 2025

Performance Basic

Francisco Manuel Gonzalez Mart

Excellent service and customer care

On-time delivery. Utmost professionalism.

Oct 22, 2025

Marstek Venus E 3.0 - 5.12 kWh

Harry O'Connor

Amazing support and great prices

Amazing support and great prices. What's not to like? Really lovely people on WhatsApp helping you with everything. Don't delay, invest in solar!

Oct 19, 2025

Marstek Venus E 3.0 - 5.12 kWh

Benz Kotzen

Delivering to us in Portugal is difficult and despite the difficulties with the Portuguese postal system, the staff at Robinsun were extremely helpful. The plug and play system we ordered was delivered within the set time frame, all pieces present and well packaged and now we are getting the 800 kWh at peak sun as promised.

Sep 13, 2025

Performance Flat

Paul Brabant

Get your equipment here

I only have good things to say about this company. I haven't experienced customer like this in Spain. Reminds me of the best companies in the US, where the customer is king. Super easy installation, quick software install, and up to 1.3kwh with 4 panels. Brilliant.

Aug 14, 2025

Plus 2000

Wies Verstraete

The service of Robinsun is outstanding

The service of Robinsun is outstanding. Although the panels were damaged in the transport (which wasn't their fault), they did everything to send new panels asap. Very easy communication via WhatsApp.

Aug 1, 2025

Performance Flat

Pedro Oliveira

Overall experience was pretty good with a package that made sense, good videos explaining how to set everything up and follow up over whatsapp to confirm everything was going as expected.

May 30, 2025

Performance Flat

IZ0 JUB

5 Star After Sales Service

I would like to thank Boris and his team for swapping out the TSUN storage battery for the ANKER Solarbank through no fault of Robinsun's the manufacturers TSUN admitted there was a problem with their equipment. The Anker is working great and giving us power all through the evening and is usually fully charged at this time of the year just after lunch. Robinsun's after sales service is second to none. 5 stars plus.

Jul 5, 2025

Anker Solarbank E1600

Eduard Frades Fabrega

I bought a basic setup without issues…

I bought a basic setup without issues and I got am excelllent support before buy the product.

May 23, 2025

Performance Basic

Moisés

The experience is very positive, they are giving you support for all the problems that you can suffer, for example, logistic, configuration. To me they are the best.

May 2, 2025

Performance Wall

Luis Gomes

Excelent products and excelent support.

Excellent products and excellent customer support. I bought a solar kit, and from the very first moment, the support via WhatsApp was excellent. Very fast delivery to Portugal without any problems. Everything worked perfectly, and I was very satisfied. I recommend Robinsun and will buy from this company again in the future.

Mar 19, 2025

Performance 800

Marco Mendes

Very good customer service

Very good customer service! Would definitely buy again from Robinsun!

Feb 24, 2025

Performance 400

Celso Vieira

Customer support is great. Instalation was very easy and fast. In no time it was working, producing power and saving the planet. Recommend to all. Good job robinsun!

Dec 13, 2024

Performance Basic

Ulrich S Barcelona

This is a very simple fast and economic way…

...to start producing solar energy by yourself in Spain. Very responsive, and smooth and fast shipment and declaration to the authorities. Very easy to assemble.

Jul 18, 2025

City 800

Paolo Tedone

Excellent customer service

Excellent customer service, fast, reliable.
Product according to description, easier than IKEA to install.
From 10am 100% coverage of baseload needs, when sunny 😉

Sep 6, 2025

Performance Flat

António Olaio

Excellent customer service

Excellent customer service. Always available and with clear and accurate information. Received the order the next day, well before the expected delivery date. 5 well-deserved stars.

Aug 28, 2025

Marstek Saturn C - B2500

Jose Antonio

Friendly service and quality materials

Very fast shipping and everything perfectly packaged. The system's anchors are high quality. The system itself is working correctly. The information and advice provided beforehand were very helpful and accurate.

Sep 9, 2025

Performance 800

Lydia C

Excellent personalized service

The team guided me through the process of choosing my kit; I didn't know anything and they explained everything to me. Highly recommended.

Nov 15, 2025

Marstek Venus E 3.0 - 5.12 kWh

Marc Borràs Conte

Everything was great!

The purchase process went very well. They answered all my questions both before and after the purchase. Excellent!

Sep 18, 2025

City 800

Juan Carlos Alguacil

Professional and friendly supplier

The purchase arrived on the expected date. I had some setup issues that the manufacturer resolved with an update. The after-sales service and customer support were friendly and prompt.

Sep 26, 2025

Marstek Jupiter C Plus

Miguel Angel Pastor Colinas

Excellent service

Excellent service, advice, and now installation follow-up. For the small amount I purchased, they've been very helpful. I hope to expand my installation with them.

Sep 30, 2025

Performance Flat

Mary Aranda

City 800 Pack Highly Recommended

I bought the City 800 pack and it works great. It's easy to install and doesn't require any advanced DIY skills. I recommend it to reduce your home's electricity consumption.

Oct 3, 2025

City 800

Carlos Calado

Excellence

The speed of delivery and the quality of the equipment and support.

Oct 14, 2025

Performance 500

shahed

Excellent Solar Investment and Outstanding Service

Purchasing the solar system has been a great decision. We’ve reduced our electricity bills by over 50% with just four solar panels. The service was very fast, and the advice was equally excellent—they helped us throughout the entire documentation process. We’ll continue buying their products because we find them to be high quality, and their customer service is outstanding

Sep 2, 2025

Plus 2000

Product FAQs

Storage

How does a storage system for my plugin solar kit work?

In short: as easy as a plugin solar kit.

There are different types of storage systems, can be divided into these main categories:

Storage for already installed plugin solar kits. If you already have a plugin solar kit with solar panels and a micro inverter installed, you can add a storage system between your solar panels and the micro inverter. These systems are generally very easy to install, and in some cases (like the Saturn C B2500) even expandable in a modular way.
All-in-one storage systems. If you want to add storage to your first plugin solar kit, an all-in-one solution is best. These systems combine batteries, controllers and micro inverters into a single system. You plug the solar panels in on one side, and connect the system straight to your home socket on the other.
Standalone storage systems. Recently a third category of storage systems has launched, that doesn’t need a direct connection to your solar panels or plugin solar kit. These independent storage systems connect to any household plug, and store all surplus power your solar kit produces. They charge and discharge through your home’s electricity network, and can also be charged with grid energy if you want to top up in low-cost times or have no solar installed at all.

Can I also charge my storage with power from the grid?

In short: with a hybrid storage system, yes.

Most storage systems that have launched in recent months include “hybrid” charging. This means that the storage system can not only discharge into the home’s power network, but also charge from it. This functionality allows you to top up your battery with power from the grid. This makes sense if your power tariff has very cheap prices in some dayparts, when topping up costs little, and use that power in the more expensive dayparts.

How much storage do I need for my home?

In short: this depends on your consumption levels.

Storage needs can be looked at from several sides:

Solar kit production. If you look at how much your solar kit produces during an entire day, and how much you consume on the spot, the rest is what you will have to store. For example, if your Plus 2000 kit produces 8 kWh per day but during the day you only use 3 kWh, then you need at least 5 kWh of storage for your surplus, to use it when the sun doesn’t shine.
Household demand. If you know how much you consume per day at home after subtracting the immediate consumption of your solar kit’s production, you know what you're missing. A part of that can be covered by storing your solar kit’s surplus. The rest can be covered by charging in low-cost hours from the grid. For example, if you consume 10 kWh per day in the above example, you will need 2 kWh to charge from the grid on top of the 5 kWh mentioned above.

And remember, that when it comes to batteries, you should never discharge below 10% and never charge over 90%. This means that you can only use 80% of any battery capacity. This would mean that in the above scenario of 7 kWh of required storage, you will need a storage system of 9 kWh, whose 80%-capacity of 7,2 kWh covers your needs.

Will a storage system also work during power outages?

In short: Some of them do.

Several storage systems that have launched recently have an “AC outlet”, also known as “emergency outlet” or “anti-blackout”. This is a Schuko socket that delivers electricity when the network goes down. These systems can also be used in homes that are not grid connected.

During power outages, like the “apagón” in Spain, Portugal and parts of France in April 2025, these systems provide critical base power to their customers, literally “keeping the lights on”. With sufficient storage capacity, and daily recharge with your solar kit, you can easily get through power outages also for longer periods of time.

See all FAQs

Marstek Saturn C - B2500