Batterie 48V ou haute tension : quel choix pour votre kit solaire ?

Choosing between a 48V battery and a high-voltage battery is a crucial decision for the efficiency of your solar kit. This technical issue, often overlooked at the time of purchase, directly influences the performance, safety and profitability of your photovoltaic installation. Let's analyse the characteristics of each solution together to help you make the right choice.

Understanding the fundamental differences

Solar batteries are mainly distinguished by their operating voltage. 48V batteries, also known as low-voltage batteries, generally operate between 48V and 51.2V nominal, while high-voltage batteries operate in a range of 300V to 800V depending on the model.

The characteristics of 48V batteries

48V lithium batteries are the benchmark solution for residential installations. At Wattuneed, we offer a complete range including Pylontech US5000 models and Delong Top Energy batteries. These batteries offer a storage capacity of between 32Ah and 314Ah, covering the energy needs of a standard family home.

• Nominal voltage: 48V to 51.2V
• Technology: Lithium Iron Phosphate (LiFePO4)
• Capacity: From 4.8kWh to 15kWh per module
• Life cycles: Over 6,000 cycles at 80% depth

The specific features of high-voltage batteries

High-voltage systems represent the technological evolution of solar energy storage. With voltages between 300V and 500V, these batteries maximise energy efficiency while reducing conversion losses.

"Our customers see a 15-20% improvement in efficiency with high-voltage systems compared to traditional 48V solutions" - Wattuneed technical expert

Comparative analysis: advantages and disadvantages

Advantages of 48V batteries

Safety and ease of installation

48V batteries offer the major advantage of safety. Their reduced voltage limits electrical risks and allows installation by experienced individuals. Pylontech US5000 batteries available from Wattuneed feature an advanced battery management system (BMS) that monitors each cell individually and communicates directly with compatible inverters.

Exceptional scalability and modularity

One of the major advantages of 48V systems is their remarkable scalability. Unlike high-voltage systems, 48V batteries allow for virtually unlimited expansion. You can start with a 4.8kWh Pylontech US5000 battery and gradually add up to 15 modules in parallel, reaching a total capacity of 72kWh.

This exceptional modularity offers unique flexibility: add a battery when your needs change, without any major technical constraints or the need to replace the existing inverter.

Controlled investment cost

Based on current prices, the Delong Top Energy 5.12kWh battery is available from Wattuneed for £968 including VAT, or approximately £189/kWh. This competitive pricing makes the investment accessible to most households wishing to optimise their solar self-consumption.

The advantages of high-voltage batteries

Superior energy efficiency

High-voltage batteries excel at optimising performance. Their high-voltage operation significantly reduces charging and discharging currents, thereby minimising resistive losses. This feature translates into 3-5% higher energy efficiency compared to 48V systems.

Compatibility with modern inverters

The new generation of Sofar ESI high-voltage inverters, available from Wattuneed, are optimised to work with high-voltage batteries such as the Sofar BTS 5K (£1,499) and Huawei Luna 2000 batteries.

Inverters and compatibility according to technology

Low-voltage inverters: robust and expandable solutions

For 48V systems, WKS Circle inverters, the DEYE range and Victron inverters represent the best on the market. We particularly recommend the DEYE range for its reliability and excellent value for money.

High-voltage inverters: optimised efficiency but less flexible

Sofar ESI inverters dominate the high-voltage segment with a complete range from 3kVA to 6kVA. Designed for Sofar BTS and Huawei Luna batteries, they offer superior efficiency but more limited scalability.

Selection criteria for your installation

1. Consumption < 8000 kWh/year: 48V battery recommended
2. Consumption 8000-15000 kWh/year: Both solutions are viable
3. Consumption > 15,000 kWh/year: High voltage preferable

Budget and return on investment

48V battery scenario:

• Initial investment: £1,950 (10kWh with Delong)
• Annual savings: £1,200
• Return on investment: 1.6 years

High-voltage scenario:

• Initial investment: €3,000 (10kWh with Sofar BTS)
• Annual savings: €1,400
• Return on investment: 2.1 years

Frequently asked questions (FAQ)

What is the lifespan of a 48V battery?

High-quality 48V lithium batteries offer more than 6,000 cycles, or approximately 15-20 years of normal use.

What is the best value for money?

In 2024, 48V batteries offer the best cost-performance compromise for residential installations. The Delong 5.12kWh at £968 offers exceptional value for money.

Wattuneed - Your renewable energy partner
Rue Henripré 12
4821 Andrimont, Belgium
Telephone: +32 87 45 00 34
Email: info@wattuneed.com