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WattCycle 48V 100Ah LiFePO4 Server Rack Battery for Home Battery Storage System
Premium BYD Cells for Reliable Power:Built with premium BYD LiFePO4 cells, this battery delivers safe, stable, and reliable long-term performance. A solid choice for UK buyers who value proven cell quality.
Built for Long-Term Protection:Designed with a rugged rack-mounted structure, a built-in 100A BMS, and 3A active balance for improved stability and cell equalisation. Backed by a 10-year warranty for long-term confidence.
Real-Time Monitoring Made Easy:Monitor voltage, current, SOC, capacity, and battery status in real time through the WattCycle App and touchscreen display. With CAN, RS232, and RS485 ports, it offers wide compatibility with Victron, Deye, Growatt, GoodWe, SOFAR, SMA, and Pylontech.
Battery Pack Certifications: IEC / CE / FCC / UN38.3.
EcoFlow Delta Expansion Ready:Compatible with EcoFlow Delta series through the proper setup and cable solution. A flexible way to expand capacity and build a larger power system.
Compact Rack Design with Strong Expandability:The 3U rack-mount design fits standard 19-inch server racks and keeps installation neat. Measuring L485mm x W450mm x H133mm and weighing 41.7kg, it is lighter than many batteries in its class.Supports 20P1S parallel connection for up to 20 batteries (max. 102.4kWh), making it ideal for home storage, workshops, farms, RV systems, and off-grid use.
Simple Setup, Ready to Use:Easy to install with a detailed user manual and a clean rack-mounted layout.
IP20 protection and floor stand installation support add flexibility for different setups.
Shipping time
Our shipping time is divided into two parts, starting from the time you place your order:
Processing time: 1-2 business days
Shipping time: 1-3 business days
Attention: The above transit time is for reference only and applies to most orders. It does not include inspection time, other special circumstances, or uncontrollable factors such as natural disasters, congestion, etc.
Shipping cost
All WattCycle orders are FREE SHIPPING.
The shipping will be delayed for some objective or uncontrolled reasons. We will notify our customers ahead of delays.
Local UK warehouse, more details in
Shipping Policy
Our batteries come with a 5-year warranty, which can be extended to 7 years total upon product registration. Accessories are covered by a 1-year warranty, and like-new (refurbished) batteries include a 1-year warranty.
For full terms, conditions, and claim details, please visit: Warranty Service
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Fast, Free Shipping
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Buy now, pay later
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Hassle-Free Warranty
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Lifetime Customer Support
In his hands-on review, “There’s A Trick For That” called the WattCycle 48V server rack battery one of the most cost-effective ways to dramatically expand portable power capacity — showing how two packs can deliver around 10× the energy storage of many OEM expansion batteries, without the premium price tag.
He praised the premium display, app integration, advanced BMS controls, and solid internal engineering, noting the clean cable routing, heavy-duty bus bars, multiple temperature sensors, and well-compressed cells.
His verdict: a thoughtfully designed battery offering impressive performance, build quality, and value for money.
Works with selected EcoFlow and BLUETTI systems via common 48V LiFePO4 expansion methods*. See the full demonstration and teardown below.
Compatibility varies by model and wiring setup. Always follow manufacturer guidance and local electrical safety requirements.
This independent user purchased and tested WattCycle batteries at his own expense and noted several visible upgrades in the latest V2.5 version. Improvements include enhanced packaging protection (with thicker boxes, upgraded foam, and added wooden reinforcement), recessed terminals for improved safety, an illuminated power switch, more durable terminal covers, and longer communication cables.
Internally, the battery continues to use 102Ah BYD cells, alongside smaller refinements such as a repositioned temperature sensor and engraved QR codes on the cells.
More importantly, the review highlights WattCycle’s responsiveness to real-world user feedback, with product updates introduced to improve usability, safety, and the overall ownership experience.
In independent testing, the reviewer highlighted the battery’s responsive touchscreen, stable inverter performance, and capacity close to its rated 100Ah. The BMS also showed fast protection response under demanding conditions.
A full teardown revealed solid internal engineering, including laser-welded connections, robust bus bars, extensive temperature monitoring, and effective thermal management — supporting the impression of a well-built, thoughtfully designed energy storage solution.
The WattCycle 48V 100Ah LiFePO4 Server Rack Batteryis designed for home energy storage, solar battery systeems, backup power, and off-grid applications.With a 5.12kWh capacity, it helps store renewable energy, suppport essential appliances during outages, and improve energy independence
Built for Safety. Designed to Last.
Featuring BYD battery cells, the battery is designed to support high safety standards and reliable performance. An upgraded physical structure further enhances durability, thermal stability, and long-term cycle life, helping ensure dependable operation over time.
Customisable Energy Storage. Broad Inverter Compatibility.
The WattCycle 48V 100Ah 3U Rack Battery is designed to scale with your energy needs, supporting expansion up to 20 batteries with automatic addressing for streamlined system integration. Its 3U rack-mounted design enables quick, seamless installation, while CAN, RS485 and RS232 communication protocols ensure compatibility with a wide range of inverter brands.Built for stable communication, strong resistance to electromagnetic interference, and fast system response, it adapts easily to home energy storage, off-grid setups, and backup power applications.
Space-Saving Design with Scalable Energy Storage
The WattCycle 3U Rack Battery fits neatly into compact installations, while modular stacking allows you to expand capacity with ease as your energy demands increase. From backup power to everyday consumption, it delivers stable, dependable performance when you need it most.
Tech Specs
Specifications
| Dimensions | 485 x 450 x 133 mm |
| Weight | 41.7kg |
| Capacity | 100Ah |
| Energy Storage | 5.12 kWh |
| Nominal Voltage | 51.2V |
| Self Discharge Rate | <3%/Month |
| Series & Parallel Connections | 1 Series(Max), 20 Parallel(Max) |
Charging
| Max. Charge Voltage | 58.4V |
| Max. Charge Current | 100A |
| Recommended Charge Current | 20A |
| Charging Temperature Protection | 0°C+5°C/55°C±5°C + 5°C |
| Discharging Temperature Protection | -20°C+5°C/60°C±5°C |
| Short Circuit Protection | Supported |
Discharging
| Continuous Discharge Current | 100A |
| Over-Current Discharge Protection | 120 A + 10 A (10 sec) |
Others
| Case Material | Heavy-Duty Cold-Rolled Steel (SPCC) |
| Certifications | IEC / CE / FCC / UN38.3 |
FAQ
For a typical UK household with solar panels, a 5.12kWh battery can help store excess daytime solar energy and use it during the evening when electricity demand is highest.
Depending on energy usage and tariff rates, many households can save between £300–£800 per year by increasing self-consumption and reducing reliance on grid electricity.
The payback period depends on electricity prices, solar generation and energy usage patterns.
For many UK homes using solar panels, a battery storage system can typically pay for itself within 4–8 years, while continuing to provide savings for many years afterwards.
With 6000+ cycle life, this battery is designed to deliver value well beyond the payback period.
Many users choose server rack batteries because they offer significantly more storage capacity per pound spent.
A single WattCycle 48V 100Ah battery provides 5.12kWh of storage, allowing users to expand their EcoFlow system at a lower cost per kWh compared with many OEM expansion battery options. Community discussions frequently highlight the cost-per-kWh advantage of 48V server rack batteries.
LiFePO4 batteries typically last several times longer than lead-acid batteries and provide more usable energy.
Although the upfront cost is higher, the cost per cycle is significantly lower, making LiFePO4 one of the most economical long-term energy storage solutions for UK homes.
Yes.
By storing solar energy during the day and using it in the evening, homeowners can increase self-consumption and reduce the amount of electricity purchased from the grid.
For many solar users, battery storage is one of the most effective ways to improve energy independence.
Yes. It supports simultaneous charging and discharging, making it suitable for solar self-consumption systems where energy is used and stored at the same time.
A 48V 100Ah LiFePO4 battery typically lasts over 6000 charge cycles, which is equivalent to around 10–15 years of daily use depending on operating conditions, depth of discharge, and usage patterns.
This makes it significantly longer-lasting than traditional lead-acid batteries, which usually last only 2–5 years.
In a typical UK household, a 5kWh LiFePO4 battery will usually last through the night when running essential appliances such as a fridge, WiFi router, and lighting.
In most cases, this means around 8 to 14 hours of reliable usage, depending on how many devices are running at the same time.
If the usage is light, for example only keeping essential standby appliances running, it can stretch closer to a full day.
A single 5kWh battery is generally not enough to run an entire UK home independently.
Instead, it is more commonly used to support essential circuits during power cuts or to store excess solar energy for use in the evening and night.
For full household coverage, most UK homes combine multiple batteries rather than relying on just one unit.
Most UK solar setups fall into three practical categories.
A single battery is usually used for emergency backup only.Two to three batteries are commonly used for everyday solar self-consumption in typical homes.Four or more batteries are typically needed if the goal is near off-grid independence.
In real UK installations, the most common choice is two to three units, as this provides a good balance between cost, storage capacity, and energy independence.
A 5kWh battery is well suited for keeping essential household devices running.
For example, it can usually keep a fridge running overnight and into the next day, power WiFi for several days, and support lighting for one to two evenings.However, appliances that draw a lot of power, such as kettles, ovens, or electric heaters, will use up the stored energy very quickly and are not ideal for battery operation.
For UK solar systems, LiFePO4 batteries are widely considered a much better long-term option than traditional lead-acid batteries.They typically last several times longer, allow more of their stored energy to be used, and do not require maintenance.
Over time, this usually results in lower total cost of ownership, even though the upfront price is higher.
Most modern UK home solar systems use 48V batteries because they are more efficient for higher power loads and larger storage capacity.Compared to 12V systems, they reduce energy loss, handle higher loads more safely, and scale much better when multiple batteries are connected together.
This makes 48V the standard choice for residential solar storage in the UK.
Yes, this type of 48V LiFePO4 battery is compatible with most modern UK solar systems.
It typically works with hybrid inverters and MPPT charge controllers from popular brands used in residential solar installations.As with any battery system, correct voltage matching and inverter compatibility should always be checked before installation.
In everyday UK residential use, a LiFePO4 battery is generally expected to last around 8 to 12 years.This is based on regular daily charging and discharging through a typical solar system.
Because UK temperatures are relatively moderate, batteries often perform more consistently compared to hotter climates.
Active balancing helps keep all internal cells inside the battery at the same voltage level during charging and discharging.
This improves overall efficiency, ensures more usable capacity over time, and helps extend the battery’s lifespan.It is especially useful in systems where multiple batteries are used together.
Compared to traditional lead-acid systems, LiFePO4 offers significantly longer lifespan, higher usable capacity, and better long-term efficiency.
Compared to many entry-level battery systems, it also provides more stable performance over repeated daily cycling, which is important for UK solar users who rely on consistent storage throughout the year.In most long-term UK solar installations, LiFePO4 is chosen because it delivers better lifetime value rather than just a lower upfront cost.
A single unit provides 5.12kWh of energy. For a typical home backup load of 500W (including a fridge, lights, and router), it can run for approximately 9–10 hours (at 90% Depth of Discharge).
Most 48V batteries use passive balancing (only 0.05A–0.1A). Our 3A active balanceris up to 30x faster, transferring energy from high-voltage to low-voltage cells in real-time. This prevents premature system shutdowns and extends the overall lifespan by ensuring cell consistency.
It supportsclosed-loop communicationvia CAN/RS485 with major brands including Victron, Growatt, Deye, Luxpower, and Solark. It can also work in open-loop mode with almost any 48V hybrid inverter on the market.
You can connect up to20 units in parallel, expanding your total capacity to 102.4kWh. This modular design allows you to start small and scale up as your home energy needs grow.
We use Grade-A BYD LiFePO4 EV-grade cells, known for their high thermal stability. Combined with a 100A Smart BMS that provides low-temperature cut-off and overcharge protection, it is safe for installation in garages or dedicated battery closets.
