Growatt ARK and HOPE batteries: models and specifications

Growatt sells two families of home battery in the UK, and the one that fits a given house is decided by the inverter already on the wall rather than by the capacity wanted. The ARK range is high-voltage, built from 2.56 kWh modules that stack from three to ten in series, giving 7.68 kWh at the bottom and 25.6 kWh at the top¹. The HOPE range is low-voltage, built from 51.2 V LiFePO4 packs sold in ready-made sets of 5, 10 and 15 kWh, with a larger 16 kWh single unit alongside them³.

The two are not interchangeable. Growatt states plainly that a battery of the wrong voltage class will not work, so an ARK stack cannot be hung on a low-voltage inverter and a HOPE pack cannot be hung on a high-voltage one¹. That single rule shapes everything else on this page: which models exist, how they expand, what they weigh and what they cost to install.

The Growatt range at a glance: ARK and HOPE

Growatt's home storage splits along a voltage line. The ARK 2.5H series is described by the maker as a modular high-voltage battery for three-phase SPH hybrid inverters, where a household starts with three modules and expands up to 25.6 kWh without replacing any accessories⁷. The HOPE 5.0L series is described as compact low-voltage rack modules for residential off-grid systems and single-phase hybrid inverters, expandable in parallel³.

That difference in voltage class is not a marketing distinction. It determines which inverter the battery can talk to, how the cells are wired, and what the installer has to do on site. A high-voltage stack runs at a few hundred volts and needs a battery management controller in the chain; a low-voltage pack runs at 51.2 V and connects in parallel³.

The wider Growatt catalogue shows how tightly the pairing is drawn. The SPH 10000TL3 and SPH 7000TL3 list the ARK 2.5H-A2 as their compatible battery¹¹. The MIN 2500-XH2 lists the ARK 2.5H-A2 and the APX 5.0P-B1¹³. The WIT-HU hybrid inverters and the SPF off-grid inverters list the HOPE packs instead¹⁴. The MOD 8000TL3-HU takes a different route again: Growatt states that a high-voltage battery can be added at any point without replacing the inverter, which is the battery-ready design in practice¹⁶.

For a household, the practical consequence is that the battery decision is usually made once, at the point the inverter is chosen. Changing voltage class later means changing the inverter, not just the battery. The wider range of Growatt storage is covered in Growatt home batteries, and the stackable principle itself in modular and stackable home batteries.

ARK 2.5H series: modular stacks from 7.68 to 25.6 kWh

The ARK family is built from one repeating part. The ARK 2.5H-A2 module is listed at 2.56 kWh of capacity and about 27 kg¹. Growatt's own product pages describe the expansion in two ways that agree on the endpoints but not on the starting point: several sets state that three to ten modules in series form a 7.68 to 25.6 kWh system, while others state that two to ten modules of 2.56 kWh in series form a 5.12 to 25.6 kWh system⁸.

The ready-made sets map onto that ladder. The 7.68 kWh set is three modules, the 10.24 kWh set is four, the 12.8 kWh set is five, and the 25.6 kWh set is ten⁸. A 20.48 kWh set is listed as eight ARK 2.5H-A2 modules plus an HVC 60050-C2 controller¹⁹. The controller is the part that manages the stack: Growatt states that battery management relies on the HVC 60050-C2 for safe operation, with an integrated BMS monitoring cell voltages, temperature and cell balance².

Usable capacity is lower than the nominal figure because the sets run to a stated depth of discharge of 90%. That gives about 6.9 kWh usable from the 7.68 kWh set, about 9.2 kWh from the 10.24 kWh set, about 11.5 kWh from the 12.8 kWh set and about 23 kWh from the 25.6 kWh set⁸. The gap between nominal and usable is the single most useful number for sizing, and it is explained further in battery capacity and usable capacity.

HOPE 5.0L-B1 packs: 5, 10 and 15 kWh low-voltage options

The HOPE range works the other way round. Instead of one module size stacked to order, Growatt sells the 5.0L-B1 as a 51.2 V LiFePO4 pack of around 5 kWh, and the sets are simply one, two or three of those packs³. The 5 kWh set is one module, the 10 kWh set is two, and the 15 kWh set is three⁴. The maker states that up to 48 packs can be connected in parallel, so capacity can grow with the installation³.

The chemistry is the same LiFePO4 used across the ARK sets, and the expansion route is parallel rather than series: Growatt states that up to 48 packs can be connected in parallel, with capacity growing to suit the installation³. That is a much larger ceiling than the ARK stack's ten modules, and it points at the off-grid and larger single-phase market the HOPE range is aimed at.

Weight is the practical constraint. The 10 kWh set is listed at 98.90 kg⁴, and the 15 kWh set at 148.40 kg⁵. These are not wall-hung units; they are floor-standing racks that need a base and a route in. The ARK range has its own mounting component, the ARK-2.5H-A1 battery base, described as providing stable, safe seating of the battery modules and accessories²⁰.

There is a naming wrinkle worth knowing. The 5.0L-B1 pack is described as around 5 kWh on some pages and 5.1 kWh on others, and the weight is given as 43±2 kg in one place and 46.25 kg in another³.

HOPE 16.0LM-A1: 16 kWh with 15.3 kWh usable

The 16.0LM-A1 sits apart from the 5.0L-B1 sets. It is a single low-voltage residential unit of 16 kWh nominal capacity with 15.3 kWh usable, which is a smaller nominal-to-usable gap than the ARK sets show⁶. Growatt lists it with a cycle life of 6000 cycles and an expansion path of up to 48 packs in parallel, giving a stated range of 16 kWh to 768 kWh in total⁶.

That ceiling is far beyond a domestic installation, and it is the clearest sign that this unit is built for stacking. For a single house, the relevant figure is the 15.3 kWh usable, which is a little more than the ARK 15 kWh set's stated 13.8 kWh usable and a little less than the ARK 25.6 kWh set's 23 kWh⁷.

The 16.0LM-A1 appears on the compatibility lists for the WIT-HU inverters alongside the AXE 5.0L-C1 and the HOPE 14.3L-A1, so it is a low-voltage partner for that inverter family rather than for the SPH three-phase range¹⁵. Weight is given as 120 kg on one page and 132.50 kg on another, another unresolved difference between documents⁶.

Specifications compared: capacity, DoD, cycle life and IP rating

The headline specifications are consistent across the ARK sets. Depth of discharge is 90%, cycle life is 6000+ cycles, and ingress protection is IP65 on the sets where it is stated⁸. The 16.0LM-A1 is listed at 6000 cycles⁶. The charge temperature across the ARK range is -10 to 50 degrees C⁸.

Two of those numbers deserve a plain reading. A 90% depth of discharge means the battery is designed to give up most of its stored energy in a cycle, which is high for lithium chemistry and is why the usable figures sit close to the nominal ones. A 6000 cycle figure is a laboratory count, not a promise about a particular house; how it translates into years depends on how hard the battery is worked, which is set out in battery cycle life and degradation.

IP65 means the enclosure is protected against dust and against water jets from any direction. It is not a licence to site a battery in a flood-prone outbuilding, and it says nothing about the temperature inside the case. The charge window of -10 to 50 degrees C is wide, but charging a cold battery is the condition most likely to be restricted in practice, and the siting questions are covered in ventilation, temperature and operating conditions.

Which inverter each battery works with, and why voltage class matters

The matching rule is the one Growatt repeats most often. The ARK 2.5H-A2 page states that the voltage class of the battery must match the inverter or the system will not work, and adds that a battery of the wrong voltage class will not work¹. The ARK 15 kWh set page puts it as: the battery must match the inverter's voltage class, otherwise the system will not work⁷. The BDC 95045-A1 base repeats the same condition for its own pairing²⁵.

In practice that produces a short compatibility list per battery. The ARK 2.5H-A2 is listed for the SPH 10000TL3, the SPH 7000TL3 and the MIN 2500-XH2¹¹. The ARK 12.8 kWh set is listed for the MIN-XH and MID-XH hybrid inverters¹⁰. The ARK 10.24 kWh set is listed for three-phase MID TL3-XH hybrid inverters¹⁸. The ARK 25.6 kWh set is listed for three-phase SPH hybrid inverters².

On the low-voltage side, the HOPE 10 kWh and 15 kWh sets are listed for the WIT-HU hybrid inverters and the SPF off-grid inverters⁴. At least one WIT-HU model is described as a low-voltage battery class inverter, and several other WIT models list the AXE 5.0L-C1, HOPE 14.3L-A1 and HOPE 16LM-A1 as compatible batteries¹⁵. The SPF 6000ES lists the AXE 5.0L-C1, ARK 2.5L-A2, HOPE 5.0L-B1 and HOPE 14.3L-A1¹⁴.

The wider point for a household is that the battery is not a standalone purchase. It is one half of a pair, and the inverter half is usually already installed or already specified. The coupling arrangements behind that pairing are explained in AC-coupled and DC-coupled battery systems.

Backup power and monitoring: what owning one means day to day

Backup is a function of the inverter, not the battery. Growatt states across the ARK and HOPE sets that, combined with a hybrid inverter, the energy storage battery keeps selected circuits running during a grid outage through the inverter's backup or EPS function⁸. The WIT 25K-HU lists a built-in EPS backup module²⁴. The phrase to hold onto is selected circuits: this is not whole-house backup, and it depends on those circuits being wired to a backed-up supply. The mechanics are set out in battery backup power and EPS.

Monitoring runs through the inverter too. The ShinePhone app and the ShineServer portal show the state of charge, the charge and discharge power and the operating history, with fault notifications⁹. That means the data depends on the inverter being online and on Growatt's servers being reachable. Local operation continues without a connection; the remote view does not. Independent guidance notes that most battery storage systems monitor battery health and will alert when a replacement is needed, which is the useful part of that data stream²⁷.

For energy independence, the position is mixed. A Growatt battery stores excess generation for later use, which is the core of self-consumption²⁸. It does not remove the grid connection, and the monitoring layer adds a dependence on broadband and a manufacturer's platform. The wider picture is in home batteries and household energy independence and monitoring a home battery.

Warranty and installation requirements

The warranty terms differ by family. The ARK sets carry a European service warranty of 10 years per the manufacturer's terms⁸. The HOPE sets are covered by a European service warranty of 5 or 10 years depending on variant³. The ARK-2.5H-A1 mounting base is listed separately at 1 year²⁰. The variant bought therefore determines the term, and the base is not covered for anything like as long as the modules it carries.

Installation is a stated condition rather than a suggestion. Growatt states that the ARK sets should be installed by a qualified installer according to the manufacturer's manual, and that the battery base is connected by a qualified installer according to the instructions and wiring diagram of the specific device, a condition of keeping the warranty⁸. The HOPE sets carry the same installer expectation through their inverter pairing.

Two independent schemes matter at the point of purchase. MCS certification is the route by which a UK installation is recognised, and the consumer standards attached to it cover how a system is sold and handed over²⁹. Battery storage is one of the technologies listed under that scheme²⁷. Checking an installer's registration before work starts is the practical step, and the process itself is covered in home battery installation and home battery warranties.