We are hiring – Electrician

We are hiring - Electrician for solar system

For the support of our team we are searching for an electrican (M/F/D) in full time in Neu-Ulm.

As a construction electrician you will complement our team and support us with solar installation work in the Ulm/Neu Ulm region and in the company’s own production.

For more information read full job description here

Send us your application

Mail: pv-systeme@bos-ag.com

How to extend your existing boat battery with lithium

How to extend your existing boat battery with lithium

Connect a lithium to a lead-acid battery system? Yes, you can! LE300 Smart Battery System is full of innovative hybrid functions and allows you to add what you want while you keep what you have.

Choosing between a lead-acid battery and a lithium system can be tough. Both have their pros and cons. While lithium requires less space and weight for the same storage capacity, it is complex to install and does not function well in the cold. Plus: It requires a high initial investment. Lead-acid batteries are affordable and simple. However, they are also heavy and tend to have a short life span.

For all those who would love to have the best of both, there is good news: You can! LE300 Smart Battery System is a plug and play lithium extension for existing 12 V lead-acid battery systems (that includes AGM and gel). Simply connect the battery cables to the positive and negative poles of your current battery and that is it. No programming, no changes to the electronics. It takes a couple of minutes.

The plug and play installation of LE300 can be done within minutes
(Image rights by Bertel Kolthof via Zeilen Media B.V.)



What you get: More capacity and even more unique features. For example, an extended lifespan of your lead-acid battery by up to ten years. LE300 will also keep it fully charged during winter, even in standby mode. With the right lithium-lead ratio, you can simply forget about batteries during the cold months and get back on the water in spring.
LE300 is modular and scalable: You can combine as many of the 28 Ah modules as you want. Well, up to 24 of them. More than enough even for long excursions. The good thing: You can adapt your capacity whenever you need it. You could start with one or two for example and add more next year – just as you need and as your budget allows it. The German manufacturer BOS AG recommends a minimum of one module per 100 Ah of lead-acid battery. Each module of LE300 weighs 3.4 kg. Thus, they even fit into small boats.

Six modules of LE300 connected to a lead-acid battery.

Pricewise, the fact that you can simply keep using your existing battery plus charging technology is a plus. It means that for the total usable battery capacity, the price per ampere-hour is significantly lower than in pure lithium systems. Simply because you already own a part of your total capacity. And why throw out what still works? Keep what you have and add what you want, that is the core principle.

By the way: This is also useful if you are thinking about an additional lead-acid battery. It is not recommendable to connect new lead-acid batteries to used ones. With LE300, you do not need to replace the existing battery to get more capacity. Just install the lithium modules.  

Here comes the sun – maximize the performance of your boat’s PV system

Here comes the sun – maximize the performance of your boat's PV system

Want to stay on the water for longer and be energy independent? Then a solar system can be a good solution. See how to get the most out of it by adding lithium to your existing battery system.

Spring is here, and just as after every long and dark winter, there is nothing better than finally getting out on the water. The longer, the better. Just yourself, some friends or family, and the beautiful purity of nature. However, to spend the longest possible time enjoying those first rays of the sun far away from it all, a reliable power supply is crucial.

For those who have enough space on their boat, a solar system can be a good investment. The batteries get recharged every day, and you get some extra time on board. But if you have a lead-acid battery system, there is a downside to it: When they are already 80 percent full or more, lead-acid batteries recharge quite slowly. They cannot absorb much energy anymore. This means that if you do not immediately use the power that your solar system is generating, you will lose it.

Solar panels on a  boat
(Image rights by Bertel Kolthof via Zeilen Media B.V.)

This puts you in a bind because you neither want to discharge your lead-acid batteries too deeply. They have the longest lifespan if they are always kept relatively full and are never discharged below 50 percent. That means that you only have about 20 or 30 percent of your battery’s capacity, which you can use to store your solar power efficiently.

Yet, there is a possibility to increase the solar system’s efficiency: by extending the lead-acid batteries with lithium. The LE300 Smart Battery System does just that. It is a plug and play solution installed in parallel with lead-acid batteries (AGM and gel are possible). It automatically extends their capacity and their lifespan by up to ten years.

Block of two LE300 modules

But why does it increase the efficiency of a solar system? That is because of the charging features of LE300. It is developed to protect lead-acid batteries by always keeping them as fully charged as possible. This means that during the charging process, it will make sure the lead-acid battery charges first. However, once the lead-acid battery starts to charge slowly, the LE300 takes up all energy that cannot be stored at that moment. Lithium cells charge quickly, so the Smart Battery System can easily take up the energy surplus in a pure lead-acid system. As the graphic shows, the combination of lead-acid and lithium battery leads to a higher charge current over a more extended amount of time. Or, to put it simply: You can store more solar energy.

Charging process of LE300 and lead-acid battery

As LE300 is a modular system, you can add as many of them as you want to your existing batteries – up to 24 in total. The German manufacturer BOS recommends at least one module per 100 Ah of lead-acid batteries. With a solar system, this combination brings excellent value for money – regarding batteries AND your solar system — a great product package for days of energy independence.

25000 LE300 sold worldwide

25000 LE300 sold worldwide India, Panama, New Zealand, Italy, Germany and many other countries: The LE300 Smart Battery System has become a well-known product internationally.


PV systems own-produced electricity

Smart Power System

produce your own electricity

Our team of solar experts is there for you! 

  • Planning of the solar systems 
  • Installation of your tailor-made solution 
  • Intelligent connection and controlling of the loads 
  • Integration of wallbox und heat pump 
  • Registration with the grid operator 
  • Documentation of the installation
For further information or non-binding offers feel free to contact us.
Oliver Haist
Department Manager PV-Systems Germany

25000 LE300 sold worldwide

25000 LE300 sold worldwide

India, Panama, New Zealand, Italy, Germany and many other countries: The LE300 Smart Battery System has become a well-known product internationally. A product whose popularity continues to grow.

And so we are now already celebrating the first 25 thousand modules sold. Or also: 8.2 megawatt hours of LE300 installed in motor homes, boats and solar systems.

A big praise to our whole team, who works every day with heart blood to secure for you a qualitative high-quality product.


[Video] New company video

[Video] New company video Watch our new company video BOS Balance of Storage Systems AG brings renewable energy all over the world with dedicated people


New Landing Page – Find your dealer for LE300 Smart Battery System

New Landing page - Find your dealer for LE300 Smart Battery System

A great product deserves its spotlight.

We are very excited and proud to announce our shiny new landing page for the LE300 Smart Battery System.

Check it out, find your dealer and learn more about the product in our blog section.


From now on, you find all our partners for the LE300 Smart Battery System with one click. You need a battery for your boat but don’t know where to find a retailer? Check out our list of all retailers worldwide. To all the mobile homeowners out there in our caravan section, find your next service partner nearby and check out the LE300 Smart Battery System. And for any other application, BOS AG got you covered. Contact us and let us know for what project you need LE300 Smart Battery System.

But wait, our website is more than finding your retailer. Read exciting reports and stories about how to use the LE300 Smart Battery System in our brand new blog section. We are coming up with regular new content.

Check it out and dive into the world of our Smart Battery System.

Together against COVID-19

People, Planet Profit – never before has our company slogan been as relevant as now, in times of COVID-19. Our core motivation in BOS is to help people live better lives, protecting the environment and strengthening economies at the same time.
And more than ever we want to do this with you, as partners, giving each other strength. Together we can get through this situation. And the best is: We can do this by helping others getting through it.
In BOS we keep up our work. We have developed the following action packages.


Power Storage in Honduras

An article about our major Honduras project appeared in the latest issue of the environmental magazine of the VDI Fachmedien. There you can read how it all began, which hurdles had to be overcome and what was finally achieved. BOS now supplies remote hotels and town halls on paradisiacal islands in Honduras with hybrid storage systems. On the Bay Islands, “HS business 10” storage units have been installed and provide a reliable power supply. With the support of dena (German Energy Agency) in the RES (renewalbe energy solutions) programme, we are helping to take one of the least electrified regions in Latin America a step further and thus to promote the economy and development.
Info: The article is in German.


CMT Stuttgart 2020

Visit us at the CMT The holiday exhibition in Stuttgart from 11. – 19. January.

Together with HYMER Original Teile + Zubehör we are pleased to present you the HYMER SMART BATTERY system in two different sizes. The innovative lithium/lead acid battery system equips all Hymer caravans with more power and offers more freedom for your travels.

See for yourself in Hall 1 Stand 1C12. We look forward to seeing you there.