I have 24V 8kWh battery. I was shocked how bad the effiency is. Highest charging I have managed is 2200W (10A) in and 1600W (27V, 60A) out, that is 72%.
Is that normal or is there something wrong with the unit or settings?
Sorry, the crystal ball is in for annual service. Perhaps provide a bit more detail about the installation and configuration, stats at the time etc.
An answer is only as good as the question and there is little to work with here.
None of that is an efficiency. The 72% is just a power ratio, however the power on discharging is given by the load, so i assume you’ve powered a 1500W load.
2200W while charging is actually a lot for a 24/3000/70, since the 70 is the max charge current. At 25.6V and 70A that would be 1792W, or lets say 1800W, of charge power. Some of the missing 400W will be gone due to the actual charge efficiency, the rest i assume was powering some load on the AC output.
But, the overall roundtrip efficiency of charging from AC and then again inverting to AC will be around 75 to 85% with all the losses in inverter, cables and the battery
1 Like
You are right, I totally ignored inverter load. With inverter off, charging is done with ~85% efficient which is expected, I guess. But battery charging never exceeds 60A for some reason.