Hoymiles HiBattery 4020S — 4kWh Stackable Battery Expansion Module
Ran out of storage before you ran out of sun? The HiBattery 4020S adds another 4.02kWh to your existing Hoymiles HiBattery 4020 X or 4020 AC. It stacks straight onto the unit you already own — no rewiring, no extra cabling, no electrician callout. Add up to three and you'll be running 16.08kWh of LiFePO4 storage.
Note: the 4020S is an expansion module. It needs a HiBattery 4020 X or 4020 AC base unit to work, and cannot be used on its own.
4.02kWh of extra LiFePO4 capacity — roughly a full evening of household load for most homes
Stacks without cables — sits directly on the base unit, connections made through the stacking interface
Up to 2,000W charge and discharge per module
Expand to 16.08kWh with up to three 4020S modules on one base unit
IP66 rated for indoor or outdoor installation
Automatic charge balancing across the stack, managed by the system BMS
Wide operating range — rated from −20°C to 55°C, so a garage or exterior wall is fine
Most homes with a single 4020 unit fill the battery by mid-afternoon in summer and then export the rest for a few pence a unit. A second module gives that energy somewhere to go. The extra capacity typically pays back fastest for households with evening-heavy consumption — EV charging, electric heating, or anyone on a time-of-use tariff who wants to buy overnight and coast through the peak.
The point of a modular system is that you don't have to guess your future consumption on day one. Start with the base unit, live with it for a winter, and add a 4020S when you know what you're short by. A heat pump, an EV, or a new home worker all change the maths — the stack changes with them.
Hoymiles designed the 4020 series around stacking rather than cabling. The 4020S locates onto the base unit and the system recognises it and rebalances state of charge across the modules by itself. Do bear in mind it weighs 35kg, so it's a two-person lift.
The 4020 series uses automotive-grade LiFePO4 cells rated beyond 8,000 cycles, with cell-level balancing, low-temperature self-heating, aerosol fire suppression and a pressure relief valve. LiFePO4 chemistry is the reason these can sit in an unheated garage and still be working in fifteen years.
ModelHB-4020-S
Usable capacity4.02 kWh
Cell chemistryLiFePO4 (lithium iron phosphate)
Max charge / discharge power2,000 W
Compatibility HiBattery 4020 X,
HiBattery 4020 AC Max modules per system3 (16.08 kWh total)
Dimensions (W × D × H)520 × 275 × 199 mm
Weight 35 kg
Ingress protection IP66
Operating temperature −20°C to 55°C
Cycle life 8,000+ cycles
Standalone operation Not supported
In the box: 1 × Hoymiles HiBattery 4020S expansion module
Can I use the 4020S on its own?
No. It has no inverter or control electronics of its own and must be paired with a HiBattery 4020 X or 4020 AC base unit.
How many can I add?
Up to three per base unit, taking total system capacity to 16.08kWh.
Do I need an electrician?
The module stacks onto the base unit without additional AC or DC wiring. It's a 35kg lift, so plan for two people. Any work affecting your existing installation should still go through a qualified installer.
Does it work with both the 4020 X and the 4020 AC?
Yes — the same module fits the PV-coupled 4020 X and the AC-coupled 4020 AC.
Can I install it outside?
Yes. The IP66 rating covers dust and water jets, and the module is rated down to −20°C.
Will mixing an older and newer module cause problems?
No. The system balances state of charge across modules automatically, so a module added later settles in with the existing stack.
The Hoymiles HiBattery 4020X is a compact, all-in-one home solar battery that stores the electricity your panels generate during the day so you can use it in the evening and overnight. It combines a 4.02kWh LFP battery, solar input and smart energy management in a single wall-mounted unit — and when your needs grow, you simply add another module.
Start at 4.02kWh. Expand to 16.08kWh. No replacing what you've already bought.
Cut what you buy from the grid. Solar generated at midday is stored rather than exported, then used when the sun goes down — the hours when most households use the most electricity.
Make time-of-use tariffs work harder. The battery can charge when electricity is cheapest and discharge during peak-rate periods, so you're buying fewer units at the expensive end of the day.
Retrofit it to solar you already have. You don't need a new system. The 4020X accepts up to 4,000W of PV input and can be added to an existing setup.
Grow the system when you're ready. Add modules as your usage changes — an EV, a heat pump, a home office — up to a total of 16.08kWh.
See exactly what it's doing. Monitor generation, storage and consumption through the Hoymiles app over Wi-Fi or Bluetooth.
Modularity is the core of the HiBattery platform. Begin with the compact 4.02kWh HiBattery 4020X and add further battery units as your energy needs increase, scaling the system to 16.08kWh in total.
Each battery contains its own bidirectional DC/DC module. That means the system automatically manages and balances differences in state of charge when new capacity is added — so a module fitted in year three works alongside your original unit without dragging it down.
The HiBattery 4020X uses lithium iron phosphate (LFP) cells, the chemistry chosen across the industry for its thermal stability. On top of that, an intelligent battery management system provides multiple layers of protection:
Internal fire-extinguishing system, activated automatically
PV input over-temperature protection
Pressure relief valve
Stack connector temperature monitoring
Intelligent cell balancing
Low-temperature battery heating
Independent overcharge and over-discharge protection
With an IP66 rating against dust and water ingress and an operating range of -20°C to 55°C, the unit is built for real British weather rather than laboratory conditions.
Hoymiles HiBattery 4020X
Battery capacity 4.02 kWh
Maximum system capacity 16.08 kWh
Maximum output power 2.5 kVA
Maximum PV input 4 × 1,000 W
Battery chemistry LFP (lithium iron phosphate)
Cycle life8,000 cycles
Energy management Hoymiles AI-EMS
Protection rating IP66
Connectivity Wi-Fi 2.4 GHz / Bluetooth
Operating temperature -20°C to +55°C
Dimensions 520 × 199 × 384 mm
Warranty10 years
Whether you're retrofitting storage to an existing solar array or designing a solar-plus-battery system from scratch, the HiBattery 4020X is a straightforward place to start — compact enough for a utility room or garage wall, and modular enough to scale when your household's demands change.
Not sure how much storage you need, or which panels and accessories pair best with it? Get in touch with our team and we'll help you specify the right system for your home.
How much is 4.02kWh in practical terms? For a typical household, roughly a third to a half of a day's electricity use — enough to cover the evening peak for most homes, and the reason many customers start here and add a second module later.
Can I add the HiBattery 4020X to solar panels I already have? Yes. It accepts up to 4,000W of PV input and is designed for retrofit as well as new installations.
How long will the battery last? The LFP cells are rated for 8,000 cycles and the unit carries a 10-year warranty.
Can I install it outside? The IP66 rating covers dust and water ingress, and the battery operates from -20°C to 55°C with low-temperature cell heating built in.
How many batteries can I link together? Up to four modules, giving a maximum system capacity of 16.08kWh.
The Fogstar Energy 48V 16.1kWh ECO battery is an energy storage solution built for homes and small commercial installs, providing reliable performance, long cycle life.
Fire Suppression
Automatic heat-activated aerosol system provides protection inside the battery.
Cold-Weather Ready
Integrated battery heating allows charging down to -10°C.
Scalable
Connect up to 16 units. That’s up to 257.6 kWh of storage.
Performance
6-year manufacturer’s warranty, backed by 10 years of Fogstar customer support.
Long Lifespan
Up to 8000 cycles at 80% Depth of Discharge.
Integration
Pre-loaded compatibility with Victron, Sunsynk, Solis, Luxpower, Voltacon and more.
Smart Connectivity
CAN and RS485 communication for smooth system integration.
User-Friendly
Integrated LCD touchscreen for real-time monitoring.
Advanced Cell Management
Advanced 200A BMS paired with JK 2A Active Balancer.
Outstanding Value
Just £108.69 per kWh.
Model: FE51.2-16
Rated Energy: 16.1kWh
Cell Assembly: 1P16S
Nominal Voltage (V): 51.2V
Operating Voltage (V): 42V - 58.2V
Cycle Life: 8000 Cycles (at 25°C 50A charge and discharge current) at 91% DOD.
Working Temperature: -10°C - 40°C Charge. -20°C - 40°C Discharge.
Rated Charge/Discharge Current (A): 100A/200A @25±2℃
Maximum Discharge Current: 200A
Capacity: 314Ah
Active Balancer: JK 2A
Weight: 119.5kg ± 3kg
Nominal Voltage: 51.2V
Size: 898.5(H) x 415(L) x 260(W)
What's Included?
1.5 m 50 mm² battery cables with M8 ring lugs, suitable for direct inverter connection or via an external busbar
1.5 m communication cable for fast, hassle-free data integration.
Installation note; always connect all negative conductors before attaching the positive. The supplied cables work with most inverter setups. However in some installations, routing via a busbar and using manufacturer-supplied inverter leads may be required.
SRNE 12V 25A Intelligent Battery Charger
The SRNE 12V 25A is a compact, durable charger for 12V batteries (LiFePO₄, AGM, GEL, flooded lead‑acid, and user-defined types). It delivers up to 25A and uses multi-stage charging (bulk, absorption, float) for fast, safe charging that extends battery life.
Features:
Automatic six-stage charging
Protections: reverse polarity, overvoltage, overcurrent, overheating, short circuit, under-temperature
Supports Li-ion activation and low‑temperature charging
Built-in Bluetooth for monitoring and adjustments
IP65 rugged housing with good heat dissipation
LED indicators for charging status
Specs:
Charging current: 25A
System voltage: 12V (battery range 9–17V)
Input: 180–264VAC, 45–65Hz
Standby power: <5W
Operating temp: -35°C to 65°C
Protection rating: IP65
Size: 347.7 × 124.1 × 66.0 mm
Weight: 1.7 kg
Bluetooth: built-in
Why Choose SRNE?
Whether for leisure batteries, marine systems, or off-grid energy storage, the SRNE 12V 25A Intelligent Charger provides dependable, efficient, and adaptable power management — the perfect companion for maintaining your batteries in peak condition.
Skyenergi Edge – Power Without Limits
Meet the Skyenergi Edge: a high-reliability, budget-friendly leisure battery featuring a 280A JBD BMS and EVE lithium cells.
Designed to be a straight swap for Lead acid batteries - simply take out your old battery and drop in the new one.
Key features
280A JBD BMS
EVE lithium cells
Durable IP67-rated housing
Customisable 4S and 4P configurations
Weight: 27.00 kilogram
Battery Capacity: 280Ah
Energy (Wh): 3584Wh
Voltage (V): 12.8V
Max Continuous Discharge Current (A): 200A
Cell Type: Eve LF280K /280Ah / 3.2v
BMS Type: JBD 200A
Heat Pads: NO
Bluetooth: NO
Dimensions: L:384mm D:194mm H:255mm
Warranty: 10 Years (Original Purchaser)
Please note: The Edge range of leisure batteries do not include bluetooth or heat pad technologies. Just connect them to your system for maintenance free use. Alternatively, you can connect them to a Victron Shunt as part of your Victron monitoring system.
Affordable. Powerful. Built to Perform.
The Skyenergi Edge is a no-nonsense lithium leisure battery designed for those who want dependable performance without paying for features they do not need with a 10-year warranty.
Do not be fooled by the price.
100A JBD BMS – A trusted battery management system for safe, stable performance
Grade A EVE Lithium Cells – High-quality cells offering excellent longevity, efficiency and consistent output
Designed for Reliability – Built to perform day after day.
Encased in a rugged IP65-rated waterproof housing, the Edge is ready for life on the move. Ideal for motorhomes, campervans, boats and off-grid systems.
Available in 4S or 4P configurations, the Skyenergi Edge gives you the flexibility to scale your battery system to match your energy requirements. It is easy to integrate into most existing setups, making installation simple and straightforward.
The Edge focuses on what matters most: rock-solid, maintenance-free performance. No unnecessary extras, no inflated price tag, just dependable lithium power you can rely on.
For customers who want detailed system monitoring, the Edge can be paired with a Victron SmartShunt for accurate real-time battery data, or pick up the data from your charge controller
Why pay more for features you do not need? The Skyenergi Edge combines rugged durability, professional-grade components and outstanding value, making it a smart choice for any off-grid power setup.
Weight: 11.00 kilogram
Battery Capacity: 100AH
Energy (Wh): 1280Wh
Voltage (V): 12.8V
Max Continuous Discharge Current (A): 100A
Cell Type: EVE LF100 /100Ah / 3.2v
BMS Type: JBD
Heat Pads: NO
Bluetooth: NO
Dimensions: L:260mm D:168mm H:209mm
Warranty: 10 Years (Original Purchaser)
For advanced battery monitoring, we recommend integration with a Victron SmartShunt.
Designed in the UK, the Fogstar Energy Storage Cabinet is built from quality materials and smart design to optimize your system. Recommended for Fogstar 51.2V 5.12kWh rack batteries, it simplifies installation, boosts performance, and offers a clean finish.
Features:
Integrated nickel-plated copper busbars for even load distribution and safe parallel connections
Vented front panels and top/bottom cable access for airflow and tidy routing
Tempered glass front door for a premium look and quick visual checks
This is the 6-rack (30 kWh) cabinet. A 3-rack (15 kWh) option is also available. Dimensions: 600 x 650 x 1250 mm
Cabinet only; batteries sold separately.
Designed in the UK, the Fogstar Energy Storage Cabinet is built from quality materials and smart engineering for reliable battery storage. Made for Fogstar 51.2V 5.12kWh Rack Batteries, it speeds up installation, boosts performance, and keeps a neat look.
Available in two sizes: 3-rack (15 kWh) and 6-rack (30 kWh) to support future expansion. Instead of individual terminal links, the cabinet uses integrated nickel-plated copper busbars for even load sharing and easy, safe parallel connections. Vented front panels improve airflow, and round cable entry points at top and bottom keep wiring tidy. A tempered glass front door provides a premium finish and quick visual checks.
Dimensions: 600 × 650 × 800 mm.
Please note that this is add is for the battery cabinet and does not include the batteries which are sold seperately.
Maximize energy independence with the Fogstar SR51.2V Server Rack Battery — UK-designed to fit off-grid systems.
Key specs:
Capacity: 5.12 kWh
Cells: EVE, 4000 cycles at 80% DOD
Integration: Pre-loaded inverter protocols (e.g., Victron, Pylontech)
Interface: LCD touchscreen to change protocols without software
Cold performance: Auto-heating to charge down to -20°C
Safety: 125 A DC breaker
Scalability: Up to 32 units (31 with Victron)
Compact, durable, and easy to integrate for reliable off-grid power.
Harness the full potential of your solar energy with the Fogstar Energy SR51.2V server rack battery. This system lets you store excess solar power generated during the day and reliably supply your home or business through the night, maintaining essential loads and comfort even during extended grid outages.
Manufacturer: Fogstar Energy
Model: ESR51.2V 5.12KWH
EVE Cell Model: LF100LA
Cell Assembly: 16S1P
Cycle Life: 4000 Cycles at 1C to 80%. (After 4000 cycles, you will still have a battery that can deliver 80% of the stated capacity) 5.12Kwh is fully useable.
BMS: PACE 100A BMS
Maximum Discharge: 100A
Balance Current: 0.5A
Capacity: 100ah
Weight: 45.2kg
Nominal Voltage: 51.2V
Rack Unit Size: 3.5U
Size: 3.5U or 450(W) x160(H) x 440(L) mm
Cabinets are available in either 3 or 6 battery configurations.
What’s included: Fogstar ESR 51.2V 5.12 kWh rack battery, PC communication cable RS232 to USB, positive 35 mm cable, and negative 35 mm cable.
Fogstar Energy warrants the Fogstar Energy 48V 5.12 kWh rack battery ("Product") to be free from defects in LiFePO4 cells, the battery management system (BMS), and overall workmanship for a period of ten (10) years from the date of purchase ("Warranty Period").
The Drift ECO is a 1,280Wh (1,250Wh usable) LiFePO4 battery for heavy-duty use — home solar, campervans, remote work, and more.
Key points:
6-year warranty.
Uses matched 12V 100A REPT cells.
Up to 3,000 cycles at 80% depth of discharge (about a 10-year life).
100A JBD BMS protects against over/under voltage, short circuits and temperature issues.
100A continuous discharge.
Chain up to 4 in series or 16 in parallel for larger systems.
Bluetooth monitoring via the Fogstar Drift app.
IP67 rugged case (dustproof and splashproof).
Compact and light: 10 kg; 260 × 168 × 209 mm.
Priced at £1.59 per Ah in the UK.
A reliable, long-lasting, cost-effective 12V leisure battery.
Free delivery and price includes VAT
The Fogstar Drift 12V 105Ah Lithium Leisure Battery — UK-designed with UK support — gives reliable power for caravans, campervans, boats, golf carts, wheelchairs, or off-grid use.
Key points:
UK design and UK-based support for peace of mind
Long life: 3500+ cycles at 80% DOD (10–15 years)
10-year warranty
Great value: £2.86 per Ah
Grade A EVE LiFePO4 cells for safety and stability
IP67 water and dust resistant
100A JBD BMS for safe, high discharge
Bluetooth monitoring via the free Fogstar Drift app
Built-in automatic heater for cold conditions
Lightweight and compact: 10 kg
Stackable: up to 4 batteries in series or parallel
Inverter-ready for up to 1000W appliances
QUICK SPECS
Energy 1280Wh
Nominal Capacity 105Ah
Nominal Voltage 12V
Recommended Charge Voltage 14.4V
Max Continuous Discharge 100A
Dimensions 260mm L x 168mm W x 209mm H
Weight 10Kg
IP67 Rated
The Fogstar Drift terminals are all M8 in size, with a 1.25mm thread pitch and 12mm length. All of our Drift Leisure batteries include M8 bolts as standard for easy, secure connections.
You can connect up to four (4) Drift batteries in series for a maximum system voltage of 48V, or link up to sixteen (16) in parallel to increase total capacity (Ah) while keeping the voltage the same. These batteries are ideal for use with inverters up to 1000W for reliable off-grid and leisure power.
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