review.solar · Sourced values document
Venus E 4.0
3 kW
MARSTEK
Plug-in ESS
Released 2026 · Evidence checked 2026-08-23 · Scored to Solar Analytica plug-in ESS rubric v1.2.0
60/100
Good
Overall
Score by category
Capacity & Usability
100
Output Power
78
Longevity (verified)
40
Safety & Chemistry
55
Guarantee & Backbone
46
Connectivity & Ecosystem
44
Sourced specification values
Published power range3 kW
Scored benchmark3 kW
Cell chemistryLFP (LiFePO4)
Usable energy / DoD100% DoD
Safety certificationCertifications not listed
Manufacturing track record4-10 years

Some values are estimated where independent verification was not available: see the full scorecard and review.solar/terms.

Page 2 · Audit sheet: complete sourced record

Venus E 4.0 · every criterion scored by the live rubric (Solar Analytica plug-in ESS rubric v1.2.0), with its recorded value, evidence status, and any linked source. Page 1 carries the buying-decision summary; this page is the full record for verification and right of reply.

Capacity & Usability
Usable energy / DoD (%)100datasheetSource +1
Modularity & scalabilityFully modular, ≤5 kWh increments, expandable in fielddatasheetSource +1
Energy density / footprintCompact high-density (integrated)datasheetSource +1
Output Power
Grid-injection power (kW)3.0datasheetSource +1
Backup output power (kW)3.0datasheetSource +1
Backup switching speed<20ms (appliance-safe)datasheetSource +1
Operating temperature rangeWide (-20°C to 55°C+)datasheetSource +1
Longevity (verified)
Cell balancing architecturePack-level only / not disclosedreviewed absenceSource +1
Warranty degradation guaranteeWarranty degradation terms not specifiedreviewed absenceSource +2
Safety & Chemistry
Cell chemistryLFP (LiFePO4)datasheetSource +1
Safety certificationCertifications not listedreviewed absenceSource +1
Thermal & fire mitigationNot specifiedreviewed absenceSource +1
Self-heating capabilityCold-weather operation not statedreviewed absenceSource +1
Ingress protection (outdoor)IP65+ outdoor-rateddatasheetSource +1
Guarantee & Backbone
Warranty assuranceNot listedreviewed absenceSource +2
Financial strength & warranty backingMid-tier private, no distress signalsdatasheetSource +1
Manufacturing track record4-10 yearsdatasheetSource +1
Connectivity & Ecosystem
Open protocol & API maturityProprietary / no documented APIreviewed absenceSource +1
VPP & grid services readinessVPP-capable, protocol readydatasheetSource +1
Smart home & IoT depthNo documented smart home integrationreviewed absenceSource +1

review.solar · audit sheet · Solar Analytica plug-in ESS rubric v1.2.0 · https://review.solar/cards/marstek-marstek-venus-e-4-0