Marstek JUPITER C Plus
An all-in-one balcony battery with a built-in micro-inverter, four solar inputs and 800 W grid output, expandable from 2.56 kWh to 10.24 kWh.
- Best for balcony solar
- All-in-one battery
- 2.56 to 10.24 kWh
- 800 W grid output
- Made by Marstek.
- Capacity: 2.56 kWh in the main unit, plus up to three 2.56 kWh extension batteries for 10.24 kWh.
- Solar: four MPPT inputs for up to 2,400 W of panels, with a built-in micro-inverter.
- Output: up to 800 W on-grid, set by hand or automatically through a smart meter.
- Rules: whether you can use it as a plug-in battery depends on your country.
Not tested by us
We have not tested the Marstek JUPITER C Plus. The figures on this page come from the sources listed at the end of the page, checked on 11 November 2026, and we do not show prices. "Best for" is based on what the maker says the product is designed for, not on our own tests.
Key figures
2.56 kWh
Capacity, up to 10.24 kWh
2,400 W
Solar input, 4 MPPT
800 W
On-grid output
Specifications
Last checked on 11 November 2026. The grey text under each name explains what the value means.
| Specification | Value |
|---|---|
| Storage | |
| CapacityHow much energy the battery stores. Bigger means longer runtime or more of your own solar power used later. | 2.56 kWh in the main unit. Each extension battery (JC+ B2500) adds 2.56 kWh, for 2.56 to 10.24 kWh in total. |
| Battery chemistryLFP (lithium iron phosphate) cells are known for long life and stable behaviour with heat. | Lithium iron phosphate (LiFePO4) |
| Cycle lifeHow many full charge and discharge cycles the cells are rated for before they hold less than the stated share of their original capacity. | More than 6,000 cycles at 25 °C, as listed for the extension battery |
| ExpansionExtra battery units that add storage to the same system. | Up to three extension batteries. They do not expand the Jupiter C/E. |
| Power | |
| AC output, grid-connectedThe lower output allowed when it feeds power into the home's circuits or the grid. | 800 VA rated (3.48 A at 230 V, 50 Hz). Marstek says 800 W on-grid, adjustable by hand or through a smart meter. |
| Backup outputA separate socket that keeps selected devices running when the grid is down. | Not stated in the sources we read |
| AC charging inputHow fast it charges from a wall socket or the grid. | Not stated in the sources we read |
| Efficiency and standby useLosses when charging, discharging and doing nothing. | MPPT efficiency up to 99.8%. Battery-to-AC efficiency and standby use are not stated. |
| Solar | |
| Solar inputsThe number of panel strings it can track separately (MPPT) and the total DC power. | Four MPPT inputs, up to 2,400 W in total, 16 to 60 V, short-circuit current 20 A. A Marstek FAQ on the same page gives a maximum of 2,000 W. |
| Grid connectionThe supply type it is built for. Check it matches your home's supply. | Single phase (L/N/PE), 230 V, 50 Hz, with a built-in micro-inverter. Works with the Marstek CT002 and Shelly Pro 3EM smart meters, and with the CT003 on a P1 meter. |
| Connection and housing | |
| Dimensions (W × D × H)Check the space before you buy, including room around it for airflow and cables. | Not stated in the sources we read |
| WeightMatters for lifting, wall mounting and moving it. | Not stated in the sources we read |
| Protection ratingIP ratings show protection from dust and water. IP55 and IP65 are rated for outdoor-style exposure; check the installation guidance. | IP65 |
| Operating temperatureThe range it is rated to work in. Cold and heat can reduce performance. | -20 to 60 °C |
| Noise levelFan noise while working. | Not stated in the sources we read |
| ConnectivityHow you monitor and control it, usually through an app. | Bluetooth, Wi-Fi and RS485; touchscreen display and the Marstek app |
| Warranty | |
| WarrantyThe period the maker covers. Read the terms: conditions and capacity guarantees differ. | Not stated in the sources we read |
Compatible with
What Marstek says this product works with. Anything not listed here is not confirmed.
- Smart meters
- Marstek says it supports the Marstek CT002 and the Shelly Pro 3EM, and the Marstek CT003 together with a P1 meter.
- Extension batteries
- Up to three JC+ B2500 extension batteries. They do not expand the Jupiter C/E.
Rules where you live
Rules for plug-in batteries differ by country, and we could not confirm a version or plug for Great Britain. In Great Britain, plug-in solar kits of up to 800 VA have been legal since 27 August 2026, but the rules exclude plug-in batteries.
Check the rules, incentives and tariffs for your own country in our country guides.
Strengths and things to check
Strengths
- Battery, BMS and micro-inverter in one unit
- Four MPPT inputs for up to 2,400 W of panels
- Expandable to 10.24 kWh
- IP65 and -20 to 60 °C operating range
Worth checking before you buy
- Whether it counts as a plug-in product depends on your country: check the rules below
- No backup output, size, weight, noise level or warranty on Marstek's product page
- Marstek's page gives 2,400 W and 2,000 W for the maximum solar input
- Grid output is 800 W
Change log
We record changes to this page here, so you can see when figures such as the warranty were last updated.
- 11 November 2026
- Page published. Warranty at publication: not stated on the Marstek product page. This page covers the JUPITER C Plus, not the JUPITER C/E.
Where this information comes from
We have not tested the JUPITER C Plus. Every figure above comes from Marstek's JUPITER C Plus product page, last checked on 11 November 2026. The page's specification table gives no size, weight, noise level, backup output or warranty, so these are shown as not stated. A value this page does not state is shown as not stated.
We do not show prices, because they change often and differ between sellers.
- Manufacturer Marstek JUPITER C Plus product page
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Common questions about Marstek JUPITER C Plus
Can I use the Marstek JUPITER C Plus as a plug-in battery in my country?
It depends on local rules. In Great Britain, plug-in solar kits up to 800 VA are legal since 27 August 2026 but the rules exclude plug-in batteries. Check our country guides.
How far can the JUPITER C Plus be expanded?
Marstek says up to three extension batteries of 2.56 kWh each, for 2.56 to 10.24 kWh. The extension batteries do not work with the Jupiter C/E.
Does the JUPITER C Plus need a separate micro-inverter?
No. Marstek describes it as an all-in-one design with the battery, BMS and micro-inverter in a single unit.
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