Bluetti AC300 split phase pv priority

I have 2 AC300s, 2 B300 and 4 B300k, I have the fusion box for the mean time and the integration kit to install. I need more panels. But my question is when I plugged in the fusion box and made them split phase, I could not pv priority with both plugged into power for backup at a certain low percentage. The other question is can I grid backup pv priority successfully? I heard that if the grid power goes down, the fusion box quits. Is this true?

Hi @DragonbloggerSheilaB, The purpose of the fusion box is to cut off the circuit by blowing the fuse when the current exceeds the rated value.
When you mentioned that the PV priority mode did not operate as set, it is possible that grid charging was enabled because the SOC fell below the configured threshold.
Please provide a screenshot of your UPS settings, the set SOC value, the actual SOC at the time grid charging occurred, and the PV input power.

Hi @dwatrous, We appreciate you taking the time to test your AC180’s performance. For the most accurate capacity measurements, we recommend using a load of around 1000W during testing.

With smaller loads, the unit’s base power consumption (self-discharge) becomes a significant factor, skewing your results
Larger loads minimize this effect, giving you a truer measure of actual capacity.

The AC180 has different running times depending on the device you’re using it with.
For high-power devices, the running time = Battery capacity × DoD × η ÷ load power.
For low-power devices, the running time = Battery capacity × DoD × η ÷ (load power + self-consumption of AC180).
DoD refers to Depth of Discharge and η is local inverter efficiency.
For AC180, DoD is 90%, η is 85%, and self-consumption is about 15W.
E.g. If you run a 100W blender with it, the running time will be:
1152Wh × 90% × 85% ÷ (100W+15W) ≈ 7.66 hrs
Note:

  1. The formula is NOT suitable for inductive loads with compressors, like refrigerator, air conditioner, etc.
  2. The above data is for reference ONLY.