Solar Battery Storage: the best options in 2024

Are you tired of seeing your electricity bill skyrocket every month? Renewable energy sources, such as solar, are becoming increasingly popular in the quest for affordable power. However, the problem of storing this energy in an affordable way has been a challenging one - until now!

LiFePO4 batteries offer the answer to all your solar energy storage needs, and in this article, we'll dive deep into why LiFePO4 offers the best battery chemistry for storing solar energy. We'll also take a closer look at the various battery options available and walk you through the battery set-up process. 

This is going to be a long one, so you might want to grab a cuppa...

Why do I need a battery for my solar array?

Anyone installing a solar array (a collection of solar panels) will require a solar battery to store the excess energy generated from the sun. Any energy generated by your solar system may not be used straight away, so having a decent battery enables you to store the excess energy until you're ready to use it at a later time. 

It's worth pointing out at this time - even if you don't have a solar array, you can still purchase a battery by itself and charge it directly from the grid during off-peak hours. 

Why is LiFePO4 the best battery chemistry for solar energy storage?

When it comes to solar energy storage, choosing the right battery chemistry is crucial. LiFePO4 (or Lithium Iron Phosphate) has emerged as the best option for solar battery storage.

Why? Let's break it down.

Longer Lifespan

LiFePO4 batteries have an impressive lifespan, lasting up to 10-15 years (or more!). This is due to their stable chemical structure which reduces the risk of degradation over time. In comparison, lead-acid batteries typically last only 2-3 years.

Safer Option

LiFePO4 batteries are a safer option for solar energy storage. They are far less prone to thermal runaway, which is a phenomenon where a battery overheats and potentially explodes. LiFePO4 batteries also have a lower risk of catching fire compared to other lithium-ion batteries and Lead Acid variants. 

Efficient Energy Storage

LiFePO4 batteries are highly efficient at storing solar energy. They have a higher depth of discharge, meaning that more of the energy stored in the battery can be used. 

Why do LiFePO4 batteries require less maintenance?

LiFePO4 batteries are well known for their low maintenance requirements due to their unique chemistry. Unlike other battery chemistries, LiFePO4 batteries have a much lower risk of overheating or catching fire. This means there is no need for extensive cooling systems or regular maintenance checks to prevent damage.

Additionally, LiFePO4 batteries have a longer lifespan compared to other battery types, which means they need to be replaced less frequently. This, in turn, reduces maintenance costs and effort on your part!

Overall, the unique chemistry of LiFePO4 batteries makes them the most reliable, low-maintenance option for storing solar energy.

How many batteries will I require for my Solar set-up?

The size of solar battery you need in the UK depends on various factors, such as your electricity usage and the size of your solar panels. Generally, a 5-10 kWh battery is a good starting point for a home solar system in the UK. However, you may need a bigger battery if you have a higher energy consumption or want to go completely off-grid.

The rule of thumb is generally to expect 50% of your annual solar production in June/July/August and only 10% in December/January/February.

The Cost of Building a LiFePO4 Solar Battery System

The cost of building a LiFePO4 solar battery can vary depending on the needs and wants of the user. However, LiFePO4 batteries are generally more expensive than other battery chemistries due to their high performance and long lifespan. Investing in the latest battery technology upfront can pay dividends in the future.

On average, a DIY 12v LiFePO4 solar battery system can cost anywhere from £545 for x4 280ah Grade B EVE Cells and a JBD 12v 200A BMS (at Fogstar.co.uk), through to £575 for x4 280ah Grade A EVE Cells and a 4-8S JK BMS with Active Balancer. 

There are other options too such as the pre-assembled 48v 100ah Fogstar Server Rack Battery for £1,249.99 which provides just over 5kWh of storage. If you're looking for a large scale system of 15kWh or more, our Rack battery also comes in both a 15kWh and 30kWh Server Rack Bundle, priced at £3999.99 and £7999.99 respectively. 

The Fogstar Drift range also offer a great storage solution with the most popular options for solar storage being the 24v 280ah LiFePO4 Battery for £1,349.00, or the 12v 560ah LiFePO4 Fogstar Drift also priced at £1,499.00.

Seplos Mason DIY battery builds are also very popular. We offer both the individual kits (£499.99), and Seplos Mason Bundles - starting at £1999.99, which also include the cells. You'll find a useful blog about these kits right here.

It's important to keep in mind that the initial cost of a LiFePO4 solar battery may be higher than other battery options, but the long-term benefits and savings make it a very worthwhile investment.

Building Your Own LiFePO4 Solar Battery System: A Beginner's Guide

Building a LiFePO4 solar battery system can be a rewarding project for both beginners and experienced DIY enthusiasts. With the right approach, you can create a cost-effective, reliable, and long-lasting energy storage solution for your solar power setup. If you're new to the world of solar batteries, we've outlined a step-by-step process to get you started.

Step 1: Determine Your Solar Battery Storage Needs

Before you start, it's essential to understand your energy storage needs. Calculate your daily energy consumption in watt hours, and ascertain the amount of storage required to power your home over a specific period. 

To give you a rough estimate, the average UK, 3-bed household uses between 8-10kWh of electricity a day. 

If you haven't already, always select your Inverter first. Your Inverter is a crucial part of your solar set-up and will dictate the size of your solar battery. Here at Fogstar, we don't sell Solar Inverters (we're battery specialists after all) - but a quick Google search and you'll find a plethora of superb inverters on the market.

Step 2: Select and Purchase your LiFePO4 Battery or Cells

It's time to make the choice on the type of battery you require - this needs to be based on your storage requirements, system and budget.

Prismatic cells are popular among DIY enthusiasts because they offer flexibility in design, while pre-built options like leisure batteries and rack systems provide a more convenient solution. 

Let's have a look at all of your options in more depth;

LiFePO4 Cells
Using LiFePO4 cells, you can assemble your own solar battery in either a 12v, 24v or 48v configuration. The great thing about LiFePO4 Cells is that you can keep adding to your pack over time, so if you need to expand your battery storage over time - it's incredibly simple to do so. As with any LiFePO4 build, you'll require a Battery Management System - here at Fogstar we sell a range of JBD, JK and Seplos LiFePO4 BMS to accompany your cells. 

If you're looking to build a 16S 48v configuration using 280ah or 304ah cells, our Seplos DIY Kits offer a great solution. Supplied with all of the critical components required to build a DIY Solar battery of up to 15.5kWh (with 304ah cells), these kits offer a great way of keeping LiFePO4 builds in a compact and neat assembly - all you need to purchase to go with them are the LiFePO4 cells of your choice.

48V Server Rack Batteries
Our Fogstar Energy Server Rack Batteries are a brand new addition to the Fogstar range and since their launch back in February 2023, we just cannot keep them in stock! At just £263 per kWh, our UK designed Server Rack Battery comes complete with 16 Grade A EVE Cells, heating, several pre-loaded inverter protocols, TFT LCD touch screen, a DC Rated Breaker, and an 8 year warranty.

We've even designed Fogstar Rack Cabinets in either a 15kWh or 30kWh capacity to safely house the batteries. These cabinets are designed with integrated, thick nickel plated copper busbars, enabling users to connect our server rack batteries in parallel with ease.  

When it comes to storing solar energy, it's important to stipulate that our 48v Rack Batteries were specially designed for use in solar installations. The ease of use and integration with a wide range of inverters, along with the plethora of additional features, has made them a popular choice with homeowners and commercial customers alike. You can read more about our rack batteries over at our previous blog.

12 and 24v Fogstar Drift Batteries
Fogstar Drift batteries have been used by hundreds of customers successfully in solar applications. Some customers even disconnect the battery over the weekend and take it with them in their Campervan! The portability, lightweight and space saving benefits of these batteries speak for themselves - and all variants of the Drift V1 can be connected by up to 4 in parallel or series. 

All Fogstar Drift batteries are manufactured using Grade A EVE LiFePO4 Lithium cells, high discharge JBD BMS, built in Bluetooth and Heating - and have a 10 year warranty. We also have a Fogstar App, allowing you to monitor the state of your leisure battery at all times.

For those not confident in assembling LiFePO4 cells, building Seplos Kits or connecting rack batteries - Drift Batteries offer a great alternative!

15.5kWh Fogstar Energy Batteries
Launching in March 2024 is our brand new Fogstar Energy 15.5kWh system. This is a pre-assembled battery unit, delivering exceptional value for money. The most affordable battery of its capacity in the world. We look forward to sharing more information on this system very soon!

Step 3: Assemble the Battery System

If you're opting to build a DIY LiFePO4 system, by this stage you'll have deciphered whether your battery build will indeed be 12v, 24V or 48v.

You need to begin by connecting the LiFePO4 cells in either series or parallel configuration to achieve the desired voltage and/or capacity. Ensure proper ventilation and use high-quality connectors, cables, and fuses. Most importantly, always follow the manufacturer's guidelines to prevent damage to the cells during assembly.

We often get asked about whether or not LiFePO4 cells require clamping together when assembled. Despite what is widely believed, the cells do not need clamping together with force. Many pack builders simply 'snug' the cells together tightly with no gaps when assembled. To finish the pack off, many DIY pack builders place very thin soft neoprene rubber inserts between the cells, use fibre tape to secure the pack, then secure the cells from either end in a 'block' (usually with the BMS on the end). If you're building out a 12v 4S pack, you can even finish off your build with one of our ABS Cell Cases.

Here are some basic LiFePO4 cell assembly guides for 12v, 24v and 48v batteries;

 
A 12v 4S configuration

A 24v 8S configuration

A 48v 16S configuration

If you’re planning on a DIY LiFePO4 build, we always recommend you have knowledge of these cells or systems before purchasing them. These cells can be incredibly dangerous if handled incorrectly, for example placing a busbar in the wrong position will cause a short circuit between 2 cells. If you’re not confident connecting the cells and BMS we suggest you opt for one of our pre-assembled units instead.

Step 4: Incorporate a Battery Management System (BMS)

A BMS is crucial in protecting your LiFePO4 battery from overcharging, over-discharging, and overheating. When selecting your LiFePO4 cells, it's important to choose a BMS compatible with your battery system, and carefully follow the installation instructions. This will optimise the performance and longevity of your solar battery storage. 

Our 48v Rack Battery and Drift Leisure batteries all come with inbuilt BMS, meaning you can skip this section entirely!

If you order one of our Seplos Mason DIY Kits to accompany your LiFePO4 cells, you'll find this kit already comes with a V3 48V 200A 16S Seplos BMS, so you won't need to purchase a further BMS as part of your build.

Step 5: Connect Your Solar Battery to the Inverter and Solar Panels

Once your LiFePO4 battery system is assembled and protected by a BMS, it's ready to be connected to your solar inverter and panels. Once connected, this will enable the battery to store energy generated by the solar panels and supply power to your home when needed.

It's crucial that you always consult an expert when you set-up your solar installation. It's also important to highlight that in the UK, all inverters that are attached to the grid in parallel (grid-tied) must be compliant with either EREC G98 or EREC G99. We recommend finding an installation specialist in your local area so they can offer a full support service should anything go awry with the system.

If you're still considering Solar Panel options, take a look at this efficiency guide from the Renewable Energy Hub - it's packed full of information and knowledge to help you make informed decisions.

Just to recap...

As the demand for renewable energy and efficient storage solutions continues to grow, LiFePO4 battery options stand out as the best choices in 2023. With their exceptional lifespan, safety, and performance, they really are ideal for harnessing the power of the sun.

Choosing the right LiFePO4 solar battery depends on factors such as budget, space, and energy requirements. With a variety of options available, it is also essential to assess your own needs, capabilities and preferences.

The future of solar energy storage is bright, and investing in a LiFePO4 solar battery storage system is not only a wise financial decision but also a step towards a more sustainable and eco-friendly future.