Marstek Venus E 3.0

Cost

Price

£1,400

Price per kWh The unit on its own, divided by its capacity. No installation is included.

£273

See it at Marstek

Battery

Battery chemistry LFP packs tolerate regular charging to 100%; NMC packs are usually happier kept below it.

LFP

Usable capacity Marstek's rated capacity. At the 90% it warrants its cycles to, about 4.6 kWh of it comes back out.

5.12 kWh

Continuous output 2.5 kVA off grid, 3.5 kVA for ten seconds, and 800 W exported to the grid as it is set up for Britain.

2.5 kW

Warranted cycles Marstek quotes more than 6,000.

6,000 cycles

Can be added to Whether you can bolt on more capacity later.

Yes

Solar input None at all. The Venus E is AC coupled: it charges off the grid when power is cheap, or off an inverter that already has the panels.

0 kW

Smart meter Marstek's own CT002, or a Shelly Pro 3EM, EM Gen3 or Pro EM-50.

Its own or Shelly

Home Assistant Nothing official, but several community integrations reach it over Modbus TCP on your own network, with no cloud in the way.

Community, local

UPS switchover Under 15 ms on the 3.0. Marstek quotes under 10 for the Venus E 4.0, which Britain does not get.

15 ms

Noise Under 30 dB, and there is no fan in it at all: the Venus E cools by natural convection.

30 dB

Depth of discharge Marstek warrants its cycles at 90%, so a 5.12 kWh Venus E is a 4.6 kWh one in practice and its price per kWh is that much worse than the table shows.

90 %

Operating temperature The range the maker will stand behind. The cold end is the one that matters in a British garden, and a battery that stops charging at zero stops charging most winter mornings.

-20 °C to 55 °C

AC sockets One emergency power socket, rated 2,500 W.

1

Charging

Weather rating The IP rating: the first digit is how well it keeps dust out, the second water. Below IP65 it wants to be indoors. Ranked as the higher number, though strictly a 7 is an immersion test where a 6 is a jets test, so one does not always include the other.

IP65

Warranty

10 years

Ethernet port Wired LAN, and RS485 on top for anyone wiring it into something older.

Yes

Wi-Fi

Yes

Bluetooth

Yes

Dimensions

Length

153 mm

Width Marstek lists 480 by 153 by 624 mm, width then depth then height.

480 mm

Height

624 mm

Weight Sixty kilos. This is not a one person lift, whatever the rest of the category manages.

60 kg

Tech

App

Yes