review.solar · Sourced values document
SUN-BK250
2.5 kW
Deye
Plug-in ESS
Released 2026 · Evidence checked 2026-07-29 · Scored to Solar Analytica plug-in ESS rubric v1.2.0
70/100
Very good
Overall
Score by category
Capacity & Usability
100
Output Power
73
Longevity (verified)
58
Safety & Chemistry
84
Guarantee & Backbone
52
Connectivity & Ecosystem
51
Sourced specification values
Published power range2.5 kW
Scored benchmark2.5 kW
Cell chemistryLFP (LiFePO4)
Usable energy / DoD100% DoD
Cycle life6000 cycles
Warranty period10 yr
Safety certificationIEC 62619 (system-level) + EN 50549 / VDE-AR-N 4105
Manufacturing track record10-15 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

SUN-BK250 · 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
Modularity & scalabilityFully modular, ≤5 kWh increments, expandable in fielddatasheetSource
Energy density / footprintCompact high-density (integrated)datasheetSource
Output Power
Grid-injection power (kW)2.5datasheetSource
Backup output power (kW)2.5datasheetSource
Backup switching speed<5ms (UPS-grade)datasheetSource
Operating temperature rangeStandard (-10°C to 50°C+)datasheetSource
Longevity (verified)
Cycle life (cycles to stated EOL)6000datasheetSource
Warranty period (yrs)10datasheetSource
Cell balancing architecturePack-level only / not disclosedstatedNo link
Warranty degradation guaranteeWarranty degradation terms not specifiedstatedNo link
Safety & Chemistry
Cell chemistryLFP (LiFePO4)datasheetSource
Safety certificationIEC 62619 (system-level) + EN 50549 / VDE-AR-N 4105datasheetSource
Thermal & fire mitigationNot specifiedstatedNo link
Self-heating capabilitySelf-heating documented as a factory option, -20°C with option fitteddatasheetSource
Ingress protection (outdoor)IP65+ outdoor-rateddatasheetSource
Guarantee & Backbone
Warranty assuranceNot listedstatedNo link
Financial strength & warranty backingMid-tier private, no distress signalsstatedNo link
Manufacturing track record10-15 yearsstatedNo link
Connectivity & Ecosystem
Open protocol & API maturityCloud API onlystatedNo link
VPP & grid services readinessVPP-capable, protocol readystatedNo link
Smart home & IoT depthNo documented smart home integrationstatedNo link

review.solar · audit sheet · Solar Analytica plug-in ESS rubric v1.2.0 · https://review.solar/cards/deye-deye-sun-bk250