12-18-2025, 06:32 PM
Since your solar battery keeps the house powered once it takes over, what matters most is the behaviour during that thirty second to two minute window before the battery picks up the load. Your current UPS shutdown timer of five to ten minutes is fine, but you can tune it a bit so the NAS does not shut down unnecessarily.
Here is the cleanest setup.
Keep the UPS in USB mode so the DS920 plus receives status directly.
Set the UPS to shut down the NAS only when the UPS itself is about to run out of power, not after a fixed delay. Most models allow you to change this from a timed shutdown to a low battery threshold. This way short outages never trigger a shutdown, because the UPS still has plenty of charge while the battery system kicks in.
If your UPS does not support low battery threshold control, change the delay to something longer, for example fifteen to twenty minutes. The house battery will stabilise power long before that, so the NAS will not shut down unless you lose both grid and battery.
If you are not home, this is the safest behaviour. The UPS covers the gap. The solar battery then takes over and the NAS keeps running without interruption. Only a true multi hour outage would drain the UPS and trigger a clean shutdown.
There is no need to manually shut down the NAS when the home switches to solar battery. The whole point of the UPS is to make these transitions smooth.
If you want, you can also set the NAS to auto power on once regular power is restored, but if the system is stable on the home battery this may not matter.
Here is the cleanest setup.
Keep the UPS in USB mode so the DS920 plus receives status directly.
Set the UPS to shut down the NAS only when the UPS itself is about to run out of power, not after a fixed delay. Most models allow you to change this from a timed shutdown to a low battery threshold. This way short outages never trigger a shutdown, because the UPS still has plenty of charge while the battery system kicks in.
If your UPS does not support low battery threshold control, change the delay to something longer, for example fifteen to twenty minutes. The house battery will stabilise power long before that, so the NAS will not shut down unless you lose both grid and battery.
If you are not home, this is the safest behaviour. The UPS covers the gap. The solar battery then takes over and the NAS keeps running without interruption. Only a true multi hour outage would drain the UPS and trigger a clean shutdown.
There is no need to manually shut down the NAS when the home switches to solar battery. The whole point of the UPS is to make these transitions smooth.
If you want, you can also set the NAS to auto power on once regular power is restored, but if the system is stable on the home battery this may not matter.