GSIKE Build a 24V LiFePO4 Off-Grid System: 28.8V, 2S 51.2V, 4P4S 40.96kWh

GSIKE 25.6V 100Ah LiFePO4 (24V class) · 8S1P · 2560Wh · 2560W continuous · 100A charge & discharge · 400A/1s pulse · charge 28.8–29.2V, cut-off 20V±0.5V · charger 25.6V 20–100A · 6000+ cycles at 100% DoD · M8 terminals · IP65 · price EUR 279.99, free EU shipping

Short answer: the GSIKE 25.6V 100Ah is a 24V DC energy store, not a complete power station. You build a system around it by pairing it with separate external parts: a solar charge controller between your panels and the battery, a charger set to the 28.8V LiFePO4 profile, fusing and M8 cabling, and — when you want household sockets — a separate 24V inverter. The battery itself holds 2560Wh and delivers up to 2560W through its 100A BMS. Expand by wiring identical packs in parallel for more runtime on the same 24V bus, in series only to reach 51.2V (a 48V-class bus), and all the way to 4P4S — sixteen packs — for a 40.96kWh house bank. This guide works through sizing, charging, wiring and expansion for RV, cabin and home storage across Europe.

The five build facts to lock in first

Before you buy panels or run a single cable, these five numbers define the whole bank.

1. Each pack stores 2560Wh at a nominal 25.6V. That is 25.6V × 100Ah = 2560Wh (2.56kWh), built as 8S1P — eight 3.2V LiFePO4 cells in series. Count packs to reach the stored energy you need.

2. Each pack draws and accepts 100A continuous — 25.6V × 100A = 2560W of continuous DC, in or out. This is the DC power ceiling. It runs an 1800W appliance comfortably (1800 < 2560). Add packs in parallel to raise that ceiling.

3. The charge setting is 28.8V ±0.4V (28.8–29.2V) on a CC/CV curve. Use a 25.6V-class charger rated 20–100A. The battery cuts itself off at 20V±0.5V when discharged.

4. The BMS protects the pack against over-charge, over-discharge, over-current, over-temperature and short circuits, and tolerates a 400A pulse for one second for motor and compressor starts.

5. Maximum expansion is 4P4S — sixteen packs. Four in series reach 102.4V, four parallel groups reach 400Ah, and 102.4V × 400Ah = 40,960Wh = 40.96kWh. The common step-up for a 48V-class bus is simply two packs in series = 51.2V / 5.12kWh.

What the 2560W DC ceiling actually means

A common mistake is reading 2560Wh of capacity and assuming the battery can pour 3000W into a heater. It cannot, from a single pack. The 100A BMS limits continuous discharge to 100A, and at 25.6V that is 2560W. The same 100A limit applies to charging. This is a DC limit on energy flow, not an alternating-current rating — the battery produces low-voltage direct current only.

If your load is a 60W fridge, the ceiling is irrelevant. If you want to run an 1800W appliance, one pack does it (70A, well under 100A). If you want 3000W continuously, one pack trips its BMS; two identical packs in parallel double the current budget to roughly 5.1kW on the same 24V bus. The 400A one-second pulse covers brief motor kicks — a compressor fridge or a pump start — without tripping anything; only sustained draws count against the 2560W figure.

Derate roughly 10–15% if the load runs through an inverter. That 1800W row is the key 24V differentiator: a 12V-class 100Ah pack (~1280W ceiling) cannot run that appliance at all, while one GSIKE 25.6V pack runs it for about 1.4 hours.

Solar charging: a separate controller, not something inside the battery

The GSIKE 25.6V 100Ah has no built-in solar regulator. Solar panels produce a varying, higher voltage that the battery cannot accept directly, so you must place an external solar charge controller between the panels and the battery. That controller converts the panel output into a clean, battery-safe current and is set to a LiFePO4 absorption voltage of 28.8V.

The battery itself follows a CC/CV (constant-current then constant-voltage) charge curve: at low state of charge it accepts current steadily, then tapers as it approaches the 28.8V±0.4V limit. The recommended everyday charger is a 25.6V-class unit rated 20–100A; the BMS will accept up to its 100A charge limit when a suitable charger supplies it. A 50A lithium charger refills a flat 2560Wh pack in roughly the time energy-divided-by-current implies — about five hours in round terms, faster on a bright solar day.

Practical charging notes: match the controller to the chemistry. Set its battery type to LiFePO4 / lithium with a 28.8V absorption. A lead-acid profile that floats lower will under-charge the pack and leave it perpetually half full. Respect the temperature window — the battery charges between 0°C and 55°C and will not charge below freezing. Size your panels to refill your daily use plus losses; the battery holds the buffer, the panels refill it.

The BMS and the 20V cut-off

Every GSIKE 25.6V 100Ah carries a 100A battery management system on board. Its job is to keep each of the eight cells within safe limits, and it disconnects rather than lets a fault propagate. The protections cover over-charge, over-discharge, over-current, over-temperature and short circuits. When discharged, the BMS disconnects at around 20V±0.5V to stop the cells being pulled too low — so plan your loads so you do not routinely ride into that cut-off.

Two consequences for your build. First, the BMS is the reason the 2560W ceiling exists: if your load demands more, the BMS limits it, so size your loads or add parallel packs rather than fighting the limit. Second, match identical units when you parallel or series them — same model, and packs bought within roughly a month of each other so their cell voltages and states of charge are close. Mixing old and new, or different models, is the most common avoidable mistake in a multi-pack bank.

Series vs parallel: how to actually wire the bank

Two wiring rules do all the work. Parallel (positive to positive, negative to negative) keeps the voltage at 25.6V and adds the amp-hours — it raises both stored energy and the current ceiling together. Series (positive of one to negative of the next) adds voltage and keeps the amp-hours the same — only do this when your inverter and charger are rated for the higher voltage.

The flagship expansion is 4P4S — sixteen packs. Four in series bring the voltage from 25.6V to 102.4V, and four of those strings in parallel bring the capacity to 400Ah. Multiply them out: 102.4V × 400Ah = 40,960Wh, or 40.96kWh. That is a genuine off-grid home-scale store. For the typical RV, cabin or small home build you will almost never need the 102.4V tier. The common step-up is just 2S — two packs in series to 51.2V — which is the everyday "48V" bus for higher-power inverters. Stay at 25.6V and add parallel packs for more runtime, and only an installer designing a 40kWh house bank would step up to 4P4S.

M8 terminals, cable lugs and fusing

The packs have M8 bolt terminals (8mm bolt, 12mm nut). Strip the cable, crimp a proper copper ring lug sized for the M8 bolt, slide it onto the post, add a washer and torque the nut down evenly. Use cable heavy enough for the current: at 100A continuous on the 24V bus, short runs want roughly 25–35mm², and longer runs should be upsized further to limit voltage drop. Because 24V pulls half the current of 12V for the same watts, your cable gauge can be noticeably thinner than a 12V equivalent.

Fit a DC fuse or circuit breaker close to the positive terminal of the battery bank — it is the device that disconnects a fault, not the BMS alone. Fuse each parallel string and again at the main bus so a short circuit in one branch cannot feed back through the others. Keep all runs short and direct, route red and black away from places they could chafe, and mount the packs on a fixed tray: at 21.15 kg each, a multi-pack bank is heavy and wants solid fixing rather than sitting loose on a shelf.

Pairing with a 24V inverter: the battery is DC, the inverter is separate

If you want to run household AC sockets — a laptop charger, a small kitchen appliance, lights on a normal plug — you need an inverter. It is a separate device that converts the battery's 25.6V direct current into the alternating current your plugs expect. The GSIKE battery itself contains no inverter and outputs no AC. As a matched companion you choose a 24V-class inverter whose DC input is rated for a 25.6V battery; its own AC ratings and sockets belong to that inverter and are read from the inverter's manual, not from the battery.

The number that constrains the pairing is the battery's 2560W per-pack DC ceiling: a single pack will not sustainably feed an inverter drawing more than about 2500W continuously, so match the inverter's continuous draw to your pack count — one pack for up to roughly 1800W of real appliances, two in parallel for a larger inverter. Keep the fused DC feed as short as possible, and size the inverter to your actual loads rather than to the biggest label on the shelf.

Sizing your build: worked examples

Build 1 — off-grid cabin, ~400Wh/day, 3 days autonomy. Stored energy needed ≈ 1200Wh of usable buffer. Add a 20–50A 28.8V charger or a sized solar controller. Simplest, lightest build: one 21.15kg pack, one fuse, one M8 feed.

Build 2 — weekend motorhome, ~1000Wh/day, 2–3 days. One pack gives about 2.5 days at 1000Wh/day on runtime alone, and handles a 60W fridge with margin. If you also want to run an 1800W kettle or heater while off-grid, the single pack covers it (1.4 hours) without a second box. Add a 24V inverter sized to that 1800W appliance and a 28.8V charger for shore power.

Build 3 — home storage / small off-grid house, ~3–5kWh/day. Move to 2P (two packs in parallel, 5.12kWh, ~5.1kW ceiling) or 4P (10.24kWh) for real daily cycling with cloudy-day buffer, paired with solar and a 24V inverter. Only a full house-scale design steps up to 2S for a 51.2V bus, or to the 4P4S sixteen-pack, 102.4V, 40.96kWh bank — and that is a job for a qualified installer.

The battery carries a 3-year warranty with a design life around 10 years, and is rated for 6000+ cycles at 100% depth of discharge, so a properly built bank is a decade-plus asset.

Final verdict — build around the box, not into it

The GSIKE 25.6V 100Ah is a rugged, 21.15kg, IP65-sealed 2560Wh DC store: 100A BMS, 2560W continuous, 28.8V charging, 20V cut-off, M8 terminals and room to expand to 40.96kWh across sixteen packs. Build the rest of the system as external, matched parts — a solar charge controller, a 28.8V lithium charger, fused M8 cabling, and a separate 24V inverter when you need AC. Respect the 2560W per-pack ceiling, parallel identical units for more runtime, and keep the whole bank at 25.6V unless a qualified installer designs the 51.2V or 102.4V series tier.

The Bottom Line — the battery stores DC; everything that makes it useful is a separate box

Avoid treating the 2560Wh pack as a complete power station. It stores 2560Wh of 25.6V DC and delivers it at up to 2560W through a 100A BMS. The solar controller, the 28.8V charger, the fuses and M8 cables, and the 24V inverter are all external partners you select and wire around it — matched, fused, and expanded in parallel for more runtime on the 24V bus, in series only up to 51.2V for a 48V-class build or the 40.96kWh ceiling when the whole house is designed for it.

Frequently asked questions

The GSIKE 25.6V 100Ah LiFePO4 battery (model GSK-25.6V-100AH) is an 8S1P, 24V-class energy-storage pack that stores 2560Wh and delivers up to 2560W continuous through a 100A BMS, rated for more than 6000 cycles at full depth of discharge in a 21.15kg IP65 ABS case — sold across Europe at €279.99, struck from a real €420.00 regular price, with free delivery and a 30-day return.

2560 Wh 25.6V / 24V class 8S1P 100A BMS 2560W ceiling 6000+ cycles 400A pulse / 1s 28.8V CC/CV IP65 M8 terminals up to 40.96 kWh bank

Same GSIKE line, three SKUs. This page sells the 25.6V 100Ah (the 24V-class pack). The table below compares it against the two 12V-class siblings so you can choose by voltage and use case. The decisive difference: at 25.6V the same 100A BMS delivers 2560W — double the 1280W of the 12V 100Ah — while pulling half the current for the same watts.

This 25.6V pack is the direct replacement for two 12V 100Ah lead-acid batteries wired IN SERIES to make 24V . Because LiFePO4 safely delivers close to its full capacity while flooded lead-acid is limited to about 50% depth of discharge, one GSIKE 25.6V 100Ah gives roughly 2.1× the usable energy of that lead-acid pair.

Keep every continuous load at or below the 2560W ceiling. The 1800W row is valid because 1800 < 2560 — that is the whole point of the 24V class over a 12V 100Ah (which tops out at 1280W and could not run it). When running through a separate 24V inverter, derate by about 90–95% efficiency and leave depth-of-discharge headroom.

The battery supports parallel and series building. Two units in series (2S) give 51.2V / 5.12kWh — the common 48V-class setup. 4P4S = four in parallel × four in series: 16 units total = 40.96 kWh (4S raises the voltage to 102.4V ; 4P raises capacity to 400Ah ; 102.4V × 400Ah = 40,960Wh).

On a wooden bench base it runs the fridge, water pump and chargers through the evening — the 2560W ceiling covers a compact 24V leisure load.

On a workbench it charges from the 28.8V source and supplies bench lighting, pumps and chargers — the 20V cut-off protects the cells.

Here the battery sits beside a separate 24V-class inverter — remember the pack itself is a battery, not an inverter, and must be matched to 24V gear.

Wire two of these in series to reach 51.2V / 5.12kWh — the common 48V setup — matching identical units within a month of age.

These are the eleven accurate official images (main unit first). Two marketing infographics are deliberately excluded: one overstates the cycle count and one labels a higher one-second peak current — neither figure is used on this page. None of the excluded numbers appear here.

Verbatim buyer reviews as submitted. This listing has no buyer photographs, so none are shown — the words are left to speak for themselves. The distribution is 12 five-star and 2 four-star reviews (Anna Nowak and Kari Virtanen), averaging 4.857, rounded to 4.9.

We upgraded our solar storage from a pair of 12V lead-acid batteries to this single 25.6V 100Ah unit and the change has been remarkable, because the higher voltage means far less current loss through the cables and the usable capacity easily covers our whole evening load, and the fact that it is lighter and a quarter smaller than the old setup while delivering two times the energy makes it a no brainer for anyone running a solar system at home.

Our off-grid cabin relies completely on solar power and this 25.6V battery has been the backbone of the system since we installed it, because it charges quickly from the panels during the day and comfortably carries the lights, the water pump and the small fridge through the night, and with the IP65 waterproof rating we do not even worry about the damp mountain air affecting it.

We fitted this battery in our motorhome to replace the original lead-acid unit and the difference in weight alone was worth it, because we have lost a huge amount of unnecessary mass and gained far more usable energy at the same time, and we can now run the fridge all night and still have plenty of power left for charging our devices in the morning.

I wanted to increase the amount of solar energy we actually use ourselves and this battery has done exactly that, because the 25.6V system integrates perfectly with our hybrid inverter and stores a serious amount of power during the sunny hours, and the intelligent Easun BMS keeps everything protected against over-charging and deep discharge so we can simply set it and forget it.

I run a small workshop with a solar setup and this battery has been powering my tools and lighting reliably for months, and the 100A continuous discharge current means even my heavier equipment runs without any noticeable voltage drop, and knowing that the cells are rated for more than six thousand cycles at full depth of discharge gives me real confidence that it will last for many years to come.

We live in an area where power cuts happen more often than we would like, so we installed this battery as a backup for our essential home loads, and it has carried us through every outage without a single problem, switching over instantly and holding its charge perfectly even when the grid was down for several hours at a time.

What really impressed me is how quickly this battery accepts a charge from my solar panels compared with the lead-acid bank I used before, because the much higher charging efficiency means I capture far more of the available sunlight, and in practice this has noticeably increased the amount of stored energy I have available in the evening, which is exactly what I was hoping for.

We take this battery on all our caravan trips and it has never disappointed us, powering the fridge, the water pump and all our electronics for the entire weekend without any issues, and the clean, maintenance free design means we simply charge it and forget about it, which is exactly the kind of hassle free experience you want when you are on the road.

The most surprising thing about this battery is how small and light it is for the amount of energy it stores, because it takes up a fraction of the space of the old battery bank and weighs far less, yet it delivers more usable power than we ever had before, and the well built casing together with the thoughtful design made the installation in our campervan completely straightforward.

When you calculate the total cost of ownership, this battery is honestly a bargain, because it is designed to last more than ten years with a three year warranty and requires absolutely no maintenance, whereas our old lead-acid batteries needed replacing every couple of years, and the eco-friendly lithium chemistry means we are also doing something good for the environment.

We use this battery with our electric trolling motor and it has performed flawlessly all season, because the high discharge current means the motor gets full power even under heavy load and there is no noticeable sag like we used to see with lead-acid, and the surge capability of 400A for a second handles the start-up current without any trouble at all.

It is still relatively early days but after two months of daily use this battery has been everything we hoped for, charging reliably from our solar panels and discharging smoothly through the night, and the peace of mind that comes from the comprehensive BMS protection against over-current, over-temperature and short circuits makes it a very easy recommendation.

We started with two of these batteries in parallel and the expandable design meant adding more units later was completely straightforward, because the system simply scales up as our energy needs grow, and now we have plenty of stored capacity to cover our whole household through the night, which has genuinely transformed how much solar energy we manage to use ourselves.

You can tell from the build quality that this is a properly engineered product, because everything from the casing to the BMS feels solid and well thought out, and after several months of daily cycling in our home energy system it still performs exactly as it did on day one, and with its ten year design life I fully expect it to serve us faithfully for many years.

With the same 100A BMS, doubling the voltage from 12.8V to 25.6V doubles the continuous DC ceiling: 12.8V×100A = 1280W, while 25.6V×100A = 2560W. That is why this pack can run an 1800W appliance (1800 < 2560), whereas a 12V 100Ah tops out at 1280W and cannot. For the same wattage the current is halved, so the runs cooler and you can use thinner cables with less voltage drop. You pay about €120 more than the 12V 100Ah for that power headroom and the 2.56kWh of energy.

No. This is an 8S1P 25.6V pack that needs a 28.8–29.2V CC/CV charge profile (28.8V ±0.4V), with a 20V cut-off. A standard 12V charger finishes at roughly 14.2–14.6V — less than half of the required charge voltage — so it will never fully charge this battery and could leave the cells chronically under-charged. Use a dedicated 25.6V LiFePO4 charger rated 20–100A.

Yes. This pack is the direct replacement for two 12V 100Ah lead-acid batteries wired in series to make 24V. Those two lead-acid cells give about 1200 usable Wh at a 50% depth of discharge, while this LiFePO4 delivers the full ~2560 usable Wh near 100% DoD — roughly 2.1× the usable energy, in one 21.15kg unit instead of ~55–60kg of lead. Keep it on the 24V bus; do not parallel it with 12V packs.

It is valid: 1800W is below the 2560W DC ceiling, so it runs continuously rather than triggering the BMS. Dividing 2560Wh by 1800W gives about 1.42 hours. On the runtime table you also get 50W 51.2h, 300W 8.53h, 1000W 2.56h and, at the full 2560W ceiling, about 1.0h. Through a separate 24V inverter, derate by 90–95% efficiency and leave DoD headroom.

No. This is a single 24V-class (25.6V) bus — do not wire it in parallel with 12V packs, and do not treat it as a 12V parallel-bank replacement. When you expand, add units that are identical in model and matched within about one month of production / charge history. Mixing new and heavily-used cells in one bank causes imbalance and shortens life; keep the whole bank on the 28.8V charge profile with the 20V cut-off.

Two units in series (2S) give 51.2V and 5.12kWh — that is the common "48V" nominal setup, and it is the usual route if you need a 48V-class inverter. At the top end, 4P4S (four parallel × four series) = 16 units for 102.4V and 400Ah, i.e. 40.96kWh. Always match identical units within about a month before wiring them in series or parallel.

A 25.6V LiFePO4 charger delivering 28.8–29.2V CC/CV at 20–100A, with the battery's 20V cut-off respected. The terminals are M8 bolts (8mm bolt / 12mm nut), so fit battery lugs that match an M8 stud and size the cables for up to 100A continuous at 25.6V — thicker short cables keep voltage loss low. Because this is a 24V pack, pair it with a 24V-rated inverter, not a 12V unit.

No. The charge window is 0°C to 55°C — do not charge below 0°C, because charging a LiFePO4 cell when it is cold can cause lithium plating and damage. It will still discharge down to −20°C. Unlike some rivals with a self-heating element or low-temperature charge cut-off, this pack has no heater and no app, so mount it where the space stays above freezing in winter.

The product-specific diagrams we use as the headline give 520×250×320mm over the terminals and 21.15kg net. Other documents list slightly different case and box figures, most likely the bare ABS case versus the packaged / shipping dimensions rather than a second product. These alternate numbers are collected in the specification note on this page, and you should confirm the true case and box dimensions with the merchant before designing a battery bay.

The 400A figure is a one-second pulse for startup inrush, not a continuous rating; one excluded marketing graphic labels a higher one-second peak, which we have not used — confirm the true peak with the merchant. The pack is priced at €279.99 struck from €420.00, in stock and new, with a 3-year warranty against a ~10-year design life. Shipping is free to 15 European countries (1–3 days handling plus 2–7 days transit), with 30-day returns by post.

Safety rules for an isolated installation: never work live, protect every branch against short circuit and sparks, protect the battery against overcharge and deep discharge, and do not exceed the continuous output limit. A pure sine wave protects sensitive electronics but does not replace correct cable and fuse sizing. If you are unsure of the wiring or battery profile, use a qualified installer; a wrong install endangers equipment and safety.

When designing an off-grid or hybrid system, start from real daily consumption: list every permanent and starting appliance, its rated power and run time, then build a daily energy budget in Wh. Only after that choose the inverter, PV array and battery; buying the equipment first and sizing the load later leads to undersizing or needlessly high cost. Homes, caravans, holiday cabins and workshops have different load profiles, so a generic recommendation for a fridge, pump or heat pump is always individual.

The MPPT charge controller is the heart of solar charging: it tracks the maximum-power point of the panels and adjusts voltage so the battery receives as much energy as possible. Compare not only the total controller current but also the panel-voltage range and the module wattage it accepts; an undersized MPPT does no damage but limits array harvest. Wire panels in series or parallel so the working voltage falls inside the controller range, respecting insulation and fuses on the PV side.

The battery provides the reserve for cloudy days and night operation. Its capacity is chosen from daily consumption and the desired autonomy days, respecting the depth of discharge of the chemistry. Lead-acid tolerates shallower depth and more frequent top-ups; LiFePO4 accepts deeper cycles. Regardless of chemistry, care for equal cell voltage, the correct charge profile and current sizing, because a mismatched profile shortens life more than the cycles themselves.

Cables and fuses are often underestimated but are a decisive part of a safe installation. At the battery's low voltage the current is high, so conductors must be short, thick and sized by current and length, keeping voltage drop and heating within normal limits. On every safety boundary (battery, panel, output) use a properly rated fuse and isolator switches; an undersized cable can overheat, and the fuse protects against short circuit and fire.

Connecting the inverter to the grid and generator has a precise procedure and switch order. Always isolate the input branches first, then connect battery, panel and AC circuit, and finally set the charge profile and parameters. Off-grid and backup mode require a clean output waveform and fast transfer time; sensitive electronics, computers and network gear need a stable wave without oscillation. Have all work checked by a qualified electrician if you do not hold the relevant competence.

Wi-Fi and monitoring let you track voltage, power, charge current and battery state directly on a phone or computer. The app shows daily gain, consumption and history, so you can spot overload or a failing cell before a fault. Daytime battery-free running with clear sun is practical, but overnight and continuous backup need the battery bank; monitoring helps distinguish array-only running from battery running.

Maintenance extends equipment life: check terminal torque, ventilation cleanliness and cooling regularly in a dry, airy room free of damp and dust. Watch charge voltage and any cell heating, and after a few years confirm battery condition and connection tightness. Avoid high humidity, dust or frost risk; respect the operating and storage temperatures stated in the manual.

When comparing models, match the same class: continuous kW, starting peak, MPPT current and range, acceptable PV wattage, battery input voltage, number of outputs and Wi-Fi connection. The listing name may not match true continuous power, so read the manual table and rating plate. A cheaper model with a smaller MPPT or no monitoring can behave worse under real load, so total value depends on the sum of parameters, not the ad slogan.

European availability and logistics affect delivery speed and return conditions. Confirm warehouse location, estimated lead time, return rules and spare-parts/support availability before buying. Prices in EUR may be shown without hidden fees, but the final price, duties and local taxes are always confirmed by the checkout. Warranty terms and the possibility of support matter more than a single monthly discount badge.

Final Verdict

Frequently asked questions

Sources and basis

1. GSIKE – 25.6V 100Ah spec sheet — https://gesike.com/products/gsike-256v100ah-product
2. LiTime – reference — https://www.litime.com
3. Renogy – reference — https://www.renogy.com
4. Battery University – LiFePO4 — https://batteryuniversity.com
5. US DOE – off-grid solar — https://www.energy.gov/energysaver

Further guides and comparisons

Direct to model: GSIKE 25.6V 100Ah LiFePO4 battery page.

GSIKE 25.6V 100Ah at 279.99 EUR (instead of 420.00 EUR) – free delivery to 15 EU countries, 30-day returns, warranty.