Solar batteries: what are the differences between Lead-acid, Ni-MH and Lithium-ion?

Solar batteries: what are the differences between Lead-acid, Ni-MH and Lithium-ion?

Solar batteries play a key role in storing the energy produced by photovoltaic panels. These solutions allow energy to be stored for powering and autonomously operating solar installations: lighting, display panels, traffic lights etc.

Several technologies and electrochemicals can be used to design a solar battery. However, the most common solar batteries are made of Lead-acid, Ni-MH and very recently Lithium-ion.

Lead-acid solar batteries: a limited technology

lead-acid is an electrochemistry historically used for battery design. The lead-acid battery consists of lead and plastic plates that are immersed in an electrolyte, usually sulphuric acid. The lead and plastic plates form the positive and negative electrodes of the battery.

Advantages of lead-acid

  • Reliability: Lead-acid batteries are reliable and can last for many years when used and maintained properly.
  • Low cost: Lead-acid batteries are often the most affordable of the different types of solar batteries, making them more competitive for buyers looking for a low-cost battery.

Limits of lead-acid

  • Required regular maintenance: Lead-acid batteries require regular maintenance to perform optimally, which can be tedious and expensive.
  • Toxic gases: Lead-acid batteries can produce toxic gases when deep discharged, i.e. discharging more than 80% of their energy capacity, which can be hazardous to health and the environment.
  • Weight: Lead-acid batteries are heavy and bulky, which can cause problems for transport and installation depending on the space available.

Ni-MH solar batteries: A commonly used technology

Ni-MH (Nickel-Metal Hydride) is a battery technology that uses a metal hydride alloy as the anode material, nickel oxyhydroxide as the cathode material and an alkaline electrolyte to allow the circulation of ions.

This battery technology has been democratised over time to overcome the limitations of lead by offering a more efficient and durable alternative. Today, Ni-MH is widely used in solar battery design because of its advantages.

The strengths of Ni-MH

  • Adapted to extreme temperature conditions: The first feature of Ni-MH is its ability to withstand harsh conditions (between -25°C and +80°C). This feature allows solar batteries made with Ni-MH to be installed in humid or hot regions such as some countries in Africa, Asia or the Middle East.
  • Longer life than lead-acid solar batteries: Ni-MH solar batteries have a longer life than lead-acid batteries, which means they require less frequent replacement and provide optimal long-term performance when properly maintained.
  • Less maintenance required: Ni-MH batteries require less maintenance than lead-acid batteries, which can be an advantage in minimising costs.
  • Easily transportable: One of the major advantages of Ni-MH batteries is that they are very easy to transport by air, land or sea compared to other technologies such as lithium. Their transport is not subject to specific regulations as they are not considered “hazardous materials”.

Beyond their advantages, Ni-MH solar batteries are now competing with more modern and promising technologies.

Lithium-ion solar batteries: A promising technology

Compared to Ni-MH, the democratisation of lithium-ion in solar is more recent. Lithium-ion generally offers better performance than its lead and Ni-MH predecessors and can meet new needs in terms of solar energy storage.

Among the multitude of lithium-ion categories on the market, LiFePO4 (Lithium Iron Phosphate) batteries are the most widely used.

Strengths of LiFePO4 solar batteries :

  • High energy density: LiFePO4 batteries have a very high energy density, which makes them more efficient for solar energy storage. They have 3 times the energy density of e.g. lead-acid batteries.
  • Longer lifespan: LiFePO4 batteries last 10 times longer than lead-acid batteries without any loss in performance. They also last longer than a Ni-MH battery.
  • On-board intelligence: As with all lithium batteries, LiFePO4 solar batteries have an integrated BMS (Battery Management System) board. This electronic management board regulates the operation of the battery by optimising charging and discharging times, protecting it against various risks (overvoltage, short-circuit, undervoltage, etc.) and optimising its performance over the long term.

In conclusion, the choice of solar battery technology depends on the customer’s project needs. The Ni-MH solar battery is an effective solution for a solar street light in a hot area. However, to power an outdoor billboard that operates 24/7, the LiFePO4 battery is a preferred alternative due to its high energy density.

Belios assists manufacturers and equipment suppliers in selecting the most suitable battery for their needs and project. From customised design to industrial production: Belios develops your solar batteries.

Would you like to have more information about Belios solar batteries or entrust us with your project? Contact our specialists.

Solar batteries: 5 reasons to choose Belios solutions

Solar batteries: 5 reasons to choose Belios solutions

Solar energy is gaining ground in the face of the current climate crisis and the need to rethink energy consumption. In addition to its environmental benefits, this source of energy is an interesting economic alternative for communities and companies, as well as an efficient way to electrify isolated areas.

For public or private lighting, video surveillance or outdoor advertising, solar energy can be used to power off-grid systems. For this, 4 components must be combined: a solar panel, an installation mast, an output to be powered (LEDs for example) and a solar battery.

The solar battery plays a crucial role in the storage and transformation of solar energy into electricity and is the central element of the solution. Equipping a high-performance and safe solution allows manufacturers of off-grid systems to take full advantage of the benefits of solar energy.

In this article we will look at 5 strong points of Belios solar batteries that make them ideal for setting up your off-grid solar system*.

*Off-grid solar system: installation that operate off-grid using solar energy

1 – 100% French solar batteries

Belios solutions are entirely designed and assembled in France. This design is carried out by in-house engineers and electronics experts and allows us to guarantee each of our customers proximity and quality support in the development of their solar batteries or in the integration of our off-the-shelf batteries into their solutions.

For French communities and professionals, choosing Belios solar batteries promotes local design and reduces the environmental impact of transport.

2 – Plug and Play batteries

Plug and play solar batteries allow immediate use after installation of the battery on the off-grid system. This type of battery saves time for both the system manufacturer and the end user.

Belios batteries can be set up quickly and easily for any solar installation.

3 – Guaranteed operation 365 days a year

The autonomy of a solar battery refers to its ability to manage energy storage between sunny and sunless periods. In order to guarantee autonomous operation throughout the year, manufacturers must ensure that the solar battery selected has a good energy density.

Belios offers a range of Longlife solar batteries using Lithium LiFeP04 (Lithium Iron Phosphate) technology. Thanks to this technology, LongLife batteries have an energy density 3 times higher than a lead-acid battery.

To optimise energy storage during periods of low sunlight, Belios integrates a SLIM card in each of its Lithium solar batteries. This management card allows a better balance between the periods of storage and use of solar energy thanks to two modules:

  • A MPPT (Maximum Power Point Tracking) module to optimise the solar charge during sunny periods
  • A BMS (Battery Management System) module to optimise the charge and discharge of the solar battery

4 – Longer life

In addition to guaranteeing the good autonomy of Belios LongLife batteries, the LifeP04 technology allows manufacturers of off-grid systems to benefit from a battery with a life 10 times longer than a lead-acid battery, without any decrease in performance.

5 – Resistance to all environments

Belios solutions have been designed to adapt to all environments thanks to their watertightness. For the most extreme environments, Belios has developed the Xtreme range, solar batteries that are resistant to wetlands, salty environments, high temperatures, etc.

This resistance is made possible by the technology used, Ni-MH (Nickel-Metal Hydride), which allows Belios to design solutions that are perfectly adapted to temperature variations between -25°C and +80°C.) This is an advantage over lead batteries, which cannot withstand temperatures above 40°C.

Would you like to know more about our solar batteries? Our commercial and technical teams are available to provide you with more information and to discuss your project. Please contact us.