Hello BLUETTI team,
I would like to ask for a confirmation or clarification regarding the operating logic of the BLUETTI EP600 in grid-connected mode, based on extensive real-world testing.
System configuration
• BLUETTI EP600 with battery modules
• DC PV connected (strings within voltage range, PV confirmed working)
• Grid connected to inverter input
• Loads connected to backup/critical-loads output
• No feed-in contract (Feed Into Grid = OFF)
• Typical constant house load: 300–500 W
Settings used (verified multiple times)
• Charge From Grid: OFF
• Time of Use: ON (tested with multiple schedules)
• SOC Low Limit: OFF
• Balanced Mode: OFF
• Winter Mode: OFF
• Generator Mode: OFF
• SOC range tested: e.g. 50–85%
All settings were applied, saved, and the system was rebooted via System Switch OFF → ON.
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Observed behavior (reproducible)
1. When the grid is available:
• The inverter remains in Grid-connected Operation
• The battery is charged and held at ~100% SOC
• PV input shows 0 W, despite sunlight being available
• House loads (300–500 W) are supplied from the grid
• This behavior persists even with Charge From Grid = OFF
2. When the grid is physically disconnected (via breaker/isolator):
• The system switches to Off-grid Operation
• PV immediately starts supplying the loads
• Battery SOC decreases normally and/or is supported by PV
• System behaves exactly as expected for PV self-consumption
3. When the grid is restored:
• The system returns to grid-connected mode
• Battery is again charged to 100%
• PV is ignored until battery SOC drops significantly or grid is removed again
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Key question to confirm
Based on the above, it appears that:
In grid-connected mode, EP600 prioritizes maintaining battery SOC (≈100%) for backup purposes and does not operate as a PV-first / self-consumption system when grid power is available, especially at low loads (300–500 W).
Please confirm:
1. Is this behavior by design?
2. Is there any firmware or setting that allows:
• PV to supply loads first
• Battery to discharge for self-consumption
• While the grid remains physically connected (but not used)?
3. Or is physical disconnection of the grid (manual or automatic via contactor) the only supported method to force PV self-consumption with EP600?
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Reason for clarification
This information is important for users who:
• Want to maximize PV self-consumption
• Use EP600 both as backup and daytime energy optimizer
• Have frequent grid outages and want predictable system behavior
At the moment, all evidence suggests that EP600 is primarily designed as an ESS / backup-oriented inverter, not a PV-first grid-tied inverter.
An official confirmation would be greatly appreciated to help users design correct and safe system architectures.
Thank you in advance.