BOS 12V 28Ah Lithium Battery Extension - LE300
BOS 12V 28Ah Lithium Battery Extension - LE300
BOS 12V 28Ah Lithium Battery Extension - LE300
BOS 12V 28Ah Lithium Battery Extension - LE300
BOS 12V 28Ah Lithium Battery Extension - LE300
BOS L3300 Lead-Acid V Lithium DOD graph
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BOS 12V 28Ah 358Wh Lithium Battery Extension - LE300

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Regular price $550.00 Sale price$495.00
Tax included. Shipping calculated at checkout.

BOS Smart Battery System:


The BOS LE300 smart battery system is a fully scalable lithium extension solution to add capacity to lead-acid batteries. Its intelligent battery management system allows an easy plug & play installation and prolongs the lifespan of both batteries by up to 10 years.

The LE300 Smart Battery System takes over most of the charging cycles while the lead-acid battery functions as cheap backup storage. The lead-acid battery is charged with a higher priority, with the lithium battery taking up the excess energy.

When discharging, the lithium battery is primarily discharged. This means that the life of the lead-acid battery is significantly extended. The LE300 detects the voltage of the lead-acid battery and automatically begins to support it with a maximum current of 12.5 A. Larger loads are supplied by the lead-acid battery and the lithium battery in parallel, which means that both batteries are discharged with less current.


Data sheet here

Brochure here

Manual here



- Our lithium battery is based on the latest lithium iron phosphate cells (LiFePO4). In addition, a Battery Management System and display are integrated in the compact housing.

- By easily stacking the modules together, the desired capacity can be achieved. The modules are connected in parallel to the lead acid batteries.

- Existing or new 12 V lead-acid batteries – including AGM and gel – can be used. The LE300 is directly connected to the positive and negative terminals of the lead-acid battery.

- Existing charge controller for lead-acid batteries with a constant voltage above 14 V or with the IoUo standard can be used.



Motorhomes & Vehicles- The LE300 Smart Battery System is specially developed for self-sustaining onboard electricity. Through an extension to the built-in battery, the system offers higher autonomy and a longer battery lifetime in motorhomes, vans, or family cars. It is also great for commercial or municipal vehicles, like for technicians or emergency services.


Boats & Yachts- Limited space is a special challenge. Due to its small yet scalable modules, LE300 Smart Battery System is an excellent addition for boats of all sizes. Moreover, the double redundancy of modular LE300 plus lead-acid battery guarantees power supply on the seven seas.


Small Solar systems- The LE300 Smart Battery System is used in small sized solar applications around the globe. It can be installed in tiny houses, at water pumps, irrigation systems and parking ticket machines.


Traffic control systems- LE300 Smart Battery System is maintenance-free and extends the lifetime of the traffic control battery. This offers many benefits and helps to save time and money.


Remote data transmission devices- The network of data transmission has expanded to far-flung regions worldwide. In many cases, areas have an unreliable or no grid supply. Freedom from maintenance, monitoring features and longer battery life are welcome in this scenario.


And many more applications- LE300 can be used wherever a classic lead-acid battery needs to be extended for example in lawnmowers or electric wheelchairs. Our customers often inspire us with new ideas and possible application areas.

SolarBox Australia will process your order within 1-2 business days. For product availability you can call us, use the chat function or email SolarBox directly at: If there is a delay on your order or your item is out of stock you will be emailed immediately to let you know.

Shipping prices are calcuated at checkout depending on weight and where it is being shipped to. View the shipping rules here

What is a warranty? A warranty is a voluntary promise offered by the person or business who sold the product or service to you. Once you buy the product or service, the promise becomes a right that can be enforced under the ACL. Warranties are separate from your automatic consumer guarantees. The consumer guarantees which apply regardless of any warranties suppliers sell or give to you, apply for a reasonable time depending on the nature of the goods or services. This means consumer guarantees may continue to apply after the time period for the warranty has expired.

View the product warranty page here for more information.

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