Lithium batteries

What is a lithium battery and why does the solar market dominate?

A lithium battery it is an electrochemical accumulator that uses lithium salts to move ions between the anode and the cathode during the loading and unloading processes. In the field of self-consumption, the predominant chemistry is the Lithium Ferrophosphate (LIFEPO4 or LFP).

Unlike lithium used in smartphones or electric cars (cobalt / nickel), batteries Lifepo4 they are designed to be stationary, extremely safe against fire and capable of supporting thousands of daily cycles without losing just capacity. On Tienda Solar, we bet on this technology because it offers the cost per kWh lower market cycling, becoming the most profitable option in the medium and long term.

Unbeatable advantages: lithium vs. Lead-acid (Gel / AGM)

To understand why lithium is the king, we must compare his metrics with conventional technologies:

1. Depth of discharge (DOD): While a gel battery should not be downloaded more than 50%, lithium allows downloads from 90% to 100%. This means that with a 5KWh lithium battery you have more useful energy than with a lead bank of 8kwh.

2. Useful life (cycles): Lead offers between 500 and 1,200 cycles. Lithium Tienda Solar guarantee between 6,000 and 10,000 cycles. This translates into more than 15-20 years of life compared to 3-5 years of lead.

3. Load efficiency: Lithium has an efficiency close to 98%, which means that almost all the energy that your panels generate is stored. Lead loses up to 20% energy in the form of heat during loading.

4. Weight and space: Lithium is 70% lighter and occupies a quarter of space. You can install 10kwh lithium in a small rack cabinet where you would need a whole room for stationary glasses.

Classification by voltage: Low voltage or high voltage?

On Tienda Solar we classify our lithium batteries in two large groups according to their work tension, a determining factor for compatibility with your inverter:

Little voltage lithium batteries (48V)

Is the standard for the residential self-consumption. Brand Pylontech they have standardized the 48V modules for their safety (security voltage) and ease of installation.

• Scalability: You can start with a 2.4kwh or 5kwh module and add more in parallel according to your needs grow.

• Compatibility: Compatible with most market hybrid investors (Victron, Voltronic, GoodWe).

High voltage lithium batteries (HV)

Systems that usually operate between the 200V and 600V. Are the trend in high-end systems like Huawei (Luna2000) or BYD (Hvs / HVM).

• Efficiency: By working for voltages similar to those of the panel series, the conversion losses are minimal.

• Power: They allow much faster loads and downloads, ideal for houses with air stopermia or electric vehicle load.

Critical components: the BMS paper (Battery Management System)

Unlike the "silly" lead batteries, lithium is an intelligent system. Each battery Tienda Solar incorporate a BMS, an electronic brain that performs vital functions:

• Balanced cells: Ensures that all internal cells have the same voltage.

• Thermal protection: Stops loading or unloading if the temperature is too high or low.

• Electrical protection: Avoid overloads, short circuits and deep discharges that could damage the chemistry of the battery.

• Communication: Send data in real time to inverter so that this knows exactly how much energy you can ask or deliver.

How to choose the correct lithium battery for your home?

Not all lithium batteries are equal. On Tienda Solar we recommend you to look at these four pillars:

1. Compatibility with the investor: It is the most critical point. Before buying, verify that the communication protocol (CAN or RS485) is compatible. If you have any doubts, consult our technical team.

2. Continuous discharge capacity: It is not the same thing that the battery stores than what you can deliver. If you have a consumption of 5KW and your battery only delivery 2.5kw, you will have to import the rest of the network.

3. Warranty and brand: Look for marks that offer at least 10 years warranty and have a technical service in Spain. On Tienda Solar we only work with solvent manufacturers.

4. Design and location: If you are going to install it in a living room, look for aesthetic models (type Huawei Moon). If you go to a garage, the rack type modules (Pylontech) They are the most practical and economical.

Installation, security and regulations in Spain

Install lithium is extremely simple thanks to its design Plug & Play, but it requires following basic rules:

• Goodbye to the "Sun Tax": Since the repeal of RD 900/2015, there is no fee for installing batteries. It is 100% legal and, in addition, is encouraged by European aid (Next Generation).

• Installation in indoor: By not emitting gases (unlike lead), you can install them indoors without forced ventilation.

• Specific wiring: Due to the high currents that handle (especially in 48V), it is vital to use adequate section cables (usually 25mm² or 35mm²) to avoid voltage drops and warm-ups.

Profitability: When do I recover the investment?

Although the initial price is higher than lead amortization of a lithium battery in Spain it is currently among the 5 and 7 years old. Since the battery will last more than 15 years, you will have at least a decade of free night energy.

In addition, lithium allows the energy arbitration: Load the battery with the network in valley hours (cheap) and use it at peak hours (faces) if your panels have not generated enough during the day.

Frequently Asked Questions (FAQ) on lithium batteries

1. Can I expand my lithium battery in the future?

Yes, it is one of its great advantages. Lithium allows you to add new modules to systems already installed. However, we recommend that they do not spend more than 2 or 3 years between extensions so that the degradation of old cells does not limit the performance of the new ones.

2. What maintenance do they require?

Absolutely none. It is only recommended to maintain the clean dust environment and ensure that communication cables are firmly connected.

3. Are they compatible with any inverter?

No. They require hybrid investors or battery chargers that have specific communication for lithium. Consult our section of Hybrid investors to see compatible combinations.

4. Does the cold influence the performance?

Yes. The lithium should not be loaded at a zero temperatures (0 ° C). Most BMS block the load under these conditions to protect the battery. If you live in very cold areas, install it inside the house.